What They Do, What the Evidence Shows & Safety.
Explore popular herbs: what each is traditionally used for, what trials in people actually found, and which medicines or conditions call for caution.
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Withania somnifera
RootLeaf
What ashwagandha (Withania somnifera) is, what trials found for stress and sleep, and the liver, thyroid, pregnancy and medicine cautions to know before using it.
Hibiscus sabdariffa L.
Flower
Hibiscus (roselle) calyces: what trials and reviews found for blood pressure and cholesterol, why medicine users and pregnant readers should ask first, and what is not known.
Taraxacum officinale
RootLeaf
Dandelion (Taraxacum officinale): what the EU herbal committee and human studies say about digestion and urine output, and the allergy, gallstone, ulcer and potassium cautions.
Lavandula angustifolia
Flower
Lavender (Lavandula angustifolia) as a herb: what trials of an oral standardized lavender oil preparation found for anxiety, what the EU says, and safety cautions.
Crocus sativus L.
Flower
Saffron (Crocus sativus) as a spice and as a supplement: what meta-analyses say about mood and anxiety, how common side effects are, bleeding and mania cautions, and fakes.
Curcuma longa, Curcuma domestica (synonym)
Rhizome
Turmeric (Curcuma longa) rhizome: what NIH and European regulators say, what joint and liver studies found, why some curcumin products are linked to liver injury, and who should ask first.
Salvia rosmarinus, Rosmarinus officinalis
Leaf
Rosemary (Salvia rosmarinus, also Rosmarinus officinalis): the EU leaf monograph and its cautions, two small oral trials on memory, and what is not known about supplement amounts.
Salvia officinalis, Salvia lavandulaefolia
Leaf
Common sage (Salvia officinalis): thujone and seizure risk at high amounts, small studies on hot flashes and memory, EU monograph limits, and pregnancy cautions.
Cynara cardunculus, Cynara scolymus
Leaf
Artichoke leaf (Cynara cardunculus): what Cochrane and meta-analyses found for indigestion and cholesterol, and EU contraindications for bile-duct, gallstone and liver disease.
Cinnamomum verum, Cinnamomum aromaticum (also called Cinnamomum cassia)
Bark
Cinnamon (Ceylon Cinnamomum verum and cassia): coumarin and liver caution, mixed blood sugar evidence, species confusion on labels, and food amounts versus supplements.
Zingiber officinale
Rhizome
Ginger rhizome (Zingiber officinale): what research and EU regulators say about nausea and digestion, plus blood-thinner, surgery, pregnancy and side-effect cautions.
Origanum vulgare
Leaf
Oregano (Origanum vulgare): food versus supplement amounts, what small studies found, a reported blood-thinner interaction, pregnancy and allergy cautions, and oil of oregano.
Vaccinium macrocarpon, Vaccinium oxycoccos
Berry / fruit
Cranberry (Vaccinium macrocarpon) and urinary tract infections: what Cochrane and NIH found for prevention, why it is not a treatment, and warfarin and kidney stone cautions.
Sambucus nigra
Berry / fruitFlower
Elderberry (Sambucus nigra): why raw berries, leaves and stems are poisonous, what reviews found for colds and flu, what is unknown, and how elderflower differs.
Silybum marianum
Seed
Milk thistle (Silybum marianum) and silymarin: what NIH and a large US trial found for liver disease and blood sugar, plus allergy, quality and pregnancy points.
Aloe vera (L.) Burm.f., Aloe barbadensis, Aloe africana, Aloe arborescens
Leaf
Aloe vera gel, latex and whole-leaf extract are different products: what NCCIH and FDA say about burns, laxative use, liver reports, animal cancer findings and pregnancy.
Foeniculum vulgare Mill., Foeniculum vulgare subsp. vulgare var. dulce (sweet fennel), Foeniculum vulgare subsp. vulgare var. vulgare (bitter fennel)
Seed
Fennel fruit or seed (Foeniculum vulgare): EU regulator limits, estragole limits for children and pregnancy, and what trials found for infant colic and digestion.
Trigonella foenum-graecum
Seed
Fenugreek (Trigonella foenum-graecum): pregnancy warning, legume allergy, blood sugar medicine cautions, mixed evidence for diabetes and milk supply, and the maple-syrup body odor.
Humulus lupulus
Flower
Hops (Humulus lupulus) beyond beer: what European regulators and trials say about sleep, stress and menopause, the estrogen-like compound, and who should ask first.
Momordica charantia
Berry / fruit
Bitter melon (Momordica charantia): a Cochrane review found insufficient evidence for blood sugar, newer reviews are more positive, and pregnancy and medicine safety data are thin.
Matricaria chamomilla, Matricaria recutita
Flower
Chamomile (Matricaria chamomilla): what NIH and EU regulators say, what trials found for anxiety and sleep, allergy risks with daisy-family plants, and medicine interactions.
Echinacea purpurea, Echinacea angustifolia, Echinacea pallida
RootWhole plant / above-ground
Echinacea (Echinacea purpurea and related species): what Cochrane, NCCIH and the EU herbal committee found for colds, and the allergy, medicine and pregnancy cautions.
Allium sativum
Bulb
Garlic (Allium sativum): bleeding risk and surgery, burns from raw garlic on skin, what reviews found for cholesterol, blood pressure and blood sugar, and safety in pregnancy.
Arnica montana
Flower
Arnica (Arnica montana) flower: skin use for bruises and sore joints, what trials found, why swallowing it is unsafe, and the daisy-family allergy, blood thinner and homeopathic cautions.
Calendula officinalis
Flower
Calendula (Calendula officinalis), pot marigold flowers: traditional skin use, what wound and radiation-skin trials found, and the daisy-family allergy and pregnancy cautions.
Solidago virgaurea
Whole plant / above-ground
Goldenrod (Solidago virgaurea): the EU traditional-use monograph for minor urinary complaints, why it is not trial-proven, and heart, kidney, diuretic and daisy-family cautions.
Melissa officinalis
Leaf
Lemon balm (Melissa officinalis): what an EU regulator, systematic reviews and liver-safety records say about stress, anxiety and sleep, and what safety questions remain open.
Mentha x piperita, Mentha × piperita L.
Leaf
Peppermint (Mentha x piperita): what research shows for IBS and indigestion, how leaf and oil differ, and heartburn, gallstone, liver and child cautions from EU and NIH sources.
Serenoa repens, Serenoa serrulata (synonym), Sabal serrulata (synonym)
Berry / fruit
Saw palmetto (Serenoa repens) berry extract: what NIH, the Cochrane Library and EU regulators say about prostate symptoms and hair loss, plus the safety points to know.
Senna alexandrina, Cassia senna, Cassia angustifolia
LeafBerry / fruit
Senna (Senna alexandrina) is a stimulant laxative for short-term constipation: what EU, UK and US guideline sources say, plus limits on use, potassium, pregnancy and laxative misuse.
Hypericum perforatum
Whole plant / above-groundFlower
St. John's wort (Hypericum perforatum): trial evidence for mild to moderate depression, and well-documented interactions with antidepressants, birth control, transplant and other medicines.
Phyllanthus emblica L., Emblica officinalis Gaertn.
Berry / fruit
Amla, or Indian gooseberry (Phyllanthus emblica), is an Ayurvedic fruit; this guide separates tradition from trial findings and covers blood-thinner and diabetes cautions.
Arctium lappa, Arctium minus, Arctium tomentosum
Root
Burdock root (Arctium lappa): EU traditional-use findings, the lack of controlled human trials, belladonna contamination reports, and daisy-family allergy cautions.
Passiflora incarnata
Whole plant / above-ground
Passionflower (Passiflora incarnata): what NIH, EU regulators and trials say about anxiety and sleep, and the cautions for pregnancy, surgery and sedating medicines.
Valeriana officinalis
Root
Valerian (Valeriana officinalis): what NIH, a sleep medicine guideline and EU regulators say about sleep, plus alcohol and sedative cautions, withdrawal effects and rare liver reports.
Nigella sativa
Seed
Black seed (Nigella sativa): what the seed is, how it has been used traditionally, what blood pressure and blood sugar trials found, and the medicine, skin and pregnancy cautions.
Eschscholzia californica
Whole plant / above-ground
California poppy (Eschscholzia californica) is used for nervousness and sleep. What the few human trials and lab studies show, and what the sources do not say about safety.
Crataegus monogyna, Crataegus laevigata, Crataegus mexicana, Crataegus pinnatifida
Berry / fruitLeafFlower
Hawthorn (Crataegus): what a Cochrane review and EMA say about heart failure and "nervous" heart complaints, digoxin and blood pressure medicine cautions, and a toxic look-alike product warning.
Lepidium meyenii, Lepidium peruvianum
Root
Maca (Lepidium meyenii) is an Andean root eaten as food and sold as a supplement; this guide separates traditional use from trial results and covers safety questions.
Rhodiola rosea
Root
What rhodiola (Rhodiola rosea) is, what trials found for fatigue, stress and mood, and cautions about antidepressants, other medicines, pregnancy and look-alike products.
Ulmus rubra
Bark
Slippery elm (Ulmus rubra) inner bark: traditional use for sore throat and gut upset, what little human evidence exists, safety notes, and why the tree is a conservation concern.
Althaea officinalis
Root
Marshmallow root (Althaea officinalis): the EU traditional-use assessment for throat irritation and dry cough, the limited trials, and the advice to space it from other medicines.
Berberis vulgaris
Berry / fruitBarkRoot
Barberry (Berberis vulgaris): what meta-analyses found for blood sugar, cholesterol and blood pressure, the berberine link, and cautions for medicines, pregnancy and newborns.
Boswellia serrata
Resin
Boswellia serrata gum-resin extract (frankincense family): what research on knee osteoarthritis found, what NIH says about safety, and the bleeding and medicine cautions from the sources.
Stellaria media
Whole plant / above-ground
Chickweed (Stellaria media): a common garden plant with traditional uses but, in the sources we read, only lab and animal research and no human trials or safety data.
Tanacetum parthenium
Leaf
Feverfew (Tanacetum parthenium) is used to try to prevent migraine: what Cochrane and EU reviews found, post-feverfew symptoms, pregnancy, bleeding and daisy-family allergy cautions.
Astragalus mongholicus, Astragalus membranaceus
Root
Astragalus (Astragalus mongholicus, also sold as A. membranaceus) is a root used in Chinese medicine; this guide covers NIH's evidence summary and the immune-medicine caution.
Vaccinium myrtillus
Berry / fruit
Bilberry (Vaccinium myrtillus): what reviews found for night vision, eye strain and blood sugar, what EU regulators accept for the fruit, and what safety information we could not find.
Centella asiatica (L.) Urb.
Whole plant / above-groundLeaf
Gotu kola (Centella asiatica): reports of liver injury, the EU skin-use monograph for minor wounds, small studies on memory and anxiety, and why "brahmi" can mean two plants.
Aesculus hippocastanum
Seed
Horse chestnut (Aesculus hippocastanum): why raw seeds, bark and leaves are toxic, what standardized seed extract showed for leg vein problems, and the EU and NIH cautions.
Glycyrrhiza glabra, Glycyrrhiza uralensis, Glycyrrhiza inflata
Root
Licorice root (Glycyrrhiza glabra): what research and EU and NIH sources say, why glycyrrhizin can raise blood pressure and lower potassium, medicine interactions, and how DGL differs.
Morinda citrifolia
Berry / fruit
Noni (Morinda citrifolia) juice and fruit: traditional use, why human evidence is thin, liver injury reports, potassium cautions for kidney disease and medicine interactions.
Frangula purshiana, Rhamnus purshiana
Bark
Cascara sagrada (Frangula purshiana, also named Rhamnus purshiana) is a bark used as a stimulant laxative: what the EU committee and US FDA say, and limits on use, potassium and pregnancy.
Gentiana lutea L.
Root
Gentian root (Gentiana lutea) is a bitter herb used traditionally for appetite and mild indigestion: what the EU herbal committee concluded, the limited evidence and the cautions.
Harpagophytum procumbens, Harpagophytum zeyheri
Root
Devil's claw root (Harpagophytum procumbens): Southern African traditional use, what trials and the EU herbal committee found for joint and back pain, stomach and gallstone cautions, and harvest concerns.
Olea europaea
Leaf
Olive leaf (Olea europaea): what EU regulators and trials say about blood pressure, blood sugar and water retention, who should ask first, and what is not known.
Schisandra chinensis, Schisandra sphenanthera
Berry / fruit
What schisandra (Schisandra chinensis) is, where the adaptogen idea began, what little human research exists, and cautions about enzyme interactions and the tacrolimus findings.
Panax quinquefolius
Root
What American ginseng (Panax quinquefolius) is, how it differs from Asian ginseng, what trials found for colds and blood sugar, the warfarin finding, and wild-harvest concerns.
Prunus africana (Hook.fil.) Kalkman, Pygeum africanum Hook f. (older name)
Bark
Pygeum (Prunus africana) bark extract is used for prostate urinary symptoms. What a Cochrane review and EU and NIH sources say, the conservation status of the tree, and safety points.
Salix alba, Salix purpurea, Salix daphnoides, Salix fragilis
Bark
White willow bark (Salix alba): the salicin and aspirin link, what trials found for back pain and osteoarthritis, and the aspirin allergy, children, blood-thinner and ulcer cautions regulators and sources list.
Inula helenium
Root
Elecampane (Inula helenium) root: traditional use for chest and skin complaints, why human evidence is not found, and the daisy-family allergy point to know.
Andrographis paniculata
Whole plant / above-groundLeaf
Andrographis (Andrographis paniculata): what systematic reviews found for cough and sore throat, reports of allergic reactions, and what the sources we read do not say.
Eleutherococcus senticosus, Acanthopanax senticosus (older name)
Root
What eleuthero (Siberian ginseng, Eleutherococcus senticosus) is, why it is not true ginseng, what trials and the EMA found, and cautions on adulteration, pregnancy and medicines.
Pelargonium sidoides, Pelargonium reniforme
Root
Pelargonium (Umckaloabo, Pelargonium sidoides): Southern African traditional use, Cochrane and EU findings on colds and bronchitis, and the disputed liver reports.
Panax ginseng
Root
What Asian ginseng (Panax ginseng) is, what research found for fatigue, thinking, blood sugar and more, and cautions about warfarin, diabetes medicines, insomnia and pregnancy.
Actaea racemosa, Cimicifuga racemosa
RootRhizome
Black cohosh (Actaea racemosa) root extract for menopause symptoms: what NIH and EU regulators found, the rare liver injury reports, adulteration and who should be careful.
Ruscus aculeatus
RhizomeRoot
Butcher's broom (Ruscus aculeatus): EU traditional-use status for heavy legs and hemorrhoid itching, what trials found, why combination-product results do not transfer, and cautions.
Petasites hybridus, Petasites officinalis, Tussilago hybrida
RootLeaf
Butterbur (Petasites hybridus) was studied for migraine, but pyrrolizidine alkaloids and rare liver injury led guidelines to stop recommending it. What the sources say.
Nepeta cataria
Whole plant / above-groundLeaf
Catnip (Nepeta cataria) is a mint-family herb used as a tea for people. We looked for human trials on calm and sleep and report what we found and did not find.
Uncaria tomentosa, Uncaria guianensis
BarkRoot
Cat's claw (Uncaria tomentosa), also called una de gato: Amazonian traditional use, why human evidence is inconclusive, and cautions for autoimmune disease, bleeding and pregnancy.
Vitex agnus-castus
Berry / fruit
Chasteberry (Vitex agnus-castus) fruit extract for PMS and breast pain: what NIH, EU regulators and a meta-analysis found, with cautions on hormone medicines and pregnancy.
Cichorium intybus
Root
Chicory root (Cichorium intybus) and its inulin fiber: what trials and meta-analyses found for constipation, how gas and bloating can limit use, and reported allergy to chicory.
Cistanche deserticola, Cistanche tubulosa
Stem
Cistanche (rou cong rong) is a parasitic plant used in Chinese medicine. What small trials found, why wild plants were protected, and what is not known about safety.
Galium aparine
Whole plant / above-ground
Cleavers (Galium aparine): what the plant is, its traditional skin and wound use, why human evidence is not found, and what safety information we could not locate.
Codonopsis pilosula, Codonopsis pilosula var. modesta, Codonopsis tangshen
Root
Codonopsis (dang shen, Codonopsis pilosula) is a Chinese herbal root sometimes called an adaptogen; this guide shows what human evidence exists, which is limited, and the safety gaps.
Coleus forskohlii (Willd.) Briq., Plectranthus barbatus Andrews, Coleus barbatus, Coleus hadiensis
Root
Coleus forskohlii and forskolin: which plant name is used, what small trials found for body fat and weight loss claims, and cautions for blood pressure and blood-thinning medicines.
Symphytum officinale, Symphytum asperum, Symphytum x uplandicum
LeafRoot
Comfrey (Symphytum officinale): why swallowing it is linked to liver injury, what the FDA, Health Canada guidance and EU regulators say, and what is known about creams and gels for the skin.
Angelica sinensis
Root
Dong quai (Angelica sinensis) root as a single herb: one placebo-controlled trial, an EU regulator statement, and cautions on warfarin, sun sensitivity, hormones and pregnancy.
Hydrastis canadensis
RootRhizome
Goldenseal (Hydrastis canadensis): no rigorous human studies for colds, why pregnancy, breastfeeding and newborns are flagged, medicine interactions, and wild-harvest concerns.
Tinospora cordifolia
Stem
Guduchi, or giloy (Tinospora cordifolia), is an Ayurvedic climber linked to liver injury reports; this guide covers the debate over causes, look-alike species and autoimmune cautions.
Commiphora wightii, Commiphora mukul (older synonym)
Resin
Guggul (Commiphora wightii): Ayurvedic tradition, why Western cholesterol trials found no benefit, rash and medicine-interaction reports, and why the wild tree is endangered.
Gymnema sylvestre
Leaf
Gymnema sylvestre leaf: its traditional use for sugar, what trials and reviews found for blood glucose and sweet cravings, and the low blood sugar caution with diabetes medicines.
Reynoutria multiflora, Polygonum multiflorum
Root
He shou wu (fo-ti, Reynoutria multiflora) is a Chinese root linked to documented liver injury. What the sources found, why processing is discussed, and who should be most careful.
Armoracia rusticana
Root
Horseradish (Armoracia rusticana) is a pungent root condiment. Human trials test it only inside a nasturtium combination for bronchitis and cystitis, and other safety data are thin.
Equisetum arvense
Whole plant / above-ground
Horsetail (Equisetum arvense) is used for urine flow, wounds and hair or nail claims. What EU assessments and trials show, plus thiaminase, nicotine, look-alike species and medicine cautions.
Hedera helix
Leaf
Ivy leaf (Hedera helix) extract for chesty cough: the EU well-established use, systematic reviews that call the benefit minimal, and allergy, age and stomach cautions.
Gynostemma pentaphyllum
Leaf
Jiaogulan (Gynostemma pentaphyllum) is a Chinese vine used as tea and extract; this guide covers small human trials, a platelet case report, and unanswered safety questions.
Juniperus communis
Berry / fruit
Juniper berry (Juniperus communis): the 2023 EU traditional-use monograph for urinary flushing and digestion, with kidney, fluid, pregnancy and children cautions.
Aloysia citrodora, Lippia citriodora (older synonym)
Leaf
Lemon verbena (Aloysia citrodora) as a tea and extract: small trials on stress, sleep, muscle recovery and blood pressure, their company links, and what is not known about safety.
Cymbopogon citratus
Leaf
Lemongrass (Cymbopogon citratus) in cooking, tea and aromatherapy: what small trials show, one trial of tea and kidney function, and cautions for pregnancy, kidney disease and allergy.
Aristotelia chilensis
Berry / fruit
Maqui berry (Aristotelia chilensis): what the fruit is, what a 2026 review of 12 human trials found for blood sugar, dry eye and other uses, and what is unknown about safety.
Leonurus cardiaca
Whole plant / above-ground
Motherwort (Leonurus cardiaca) for nervous tension and heart-related nervousness: the European traditional-use statement, one small trial, and the pregnancy contraindication.
Verbascum thapsus, Verbascum densiflorum, Verbascum phlomoides
LeafFlower
Mullein (Verbascum thapsus): what traditional use and EU herbal assessments say, why human evidence for coughs is thin, and the safety points for pregnancy, children and medicines.
Azadirachta indica
LeafBarkSeed
Neem (Azadirachta indica): why swallowing neem oil has caused severe poisoning in children and adults, what research shows for mouth rinses and skin, and Ayurvedic background.
Mahonia aquifolium, Berberis aquifolium (synonym)
RootBark
Oregon grape (Mahonia aquifolium): what reviews and trials found for psoriasis creams, its berberine content, and cautions for medicines, pregnancy and newborns.
Panax notoginseng (Burkill) F.H.Chen ex C.H.Chow
Root
Notoginseng (sanqi, Panax notoginseng) is a Chinese root used for bruising and bleeding. What trials of hospital preparations show, and why blood thinner cautions matter.
Vinca minor
Whole plant / above-groundLeaf
Lesser periwinkle (Vinca minor) and vinpocetine, the lab-made compound sold as a memory supplement: what FDA, Cochrane and other sources say about evidence and pregnancy.
Pinus massoniana Lamb., Pinus radiata D.Don, Pinus spp.
Pollen
Pine pollen, collected from Pinus trees, is sold for energy and testosterone. We found no human trials, only animal and cell studies, plus allergy reports to check.
Plantago major
LeafSeed
Plantain leaf (Plantago major): what this common leaf is, how it differs from psyllium and the cooking fruit, and what trials, animal studies and EU monographs say about wounds and cough.
Rubus idaeus L.
Leaf
Red raspberry leaf (Rubus idaeus) is widely used in pregnancy. What the labor trials and reviews found, what is not known about safety, and why to tell your midwife.
Trifolium pratense
Flower
Red clover (Trifolium pratense) isoflavone extracts for menopause symptoms: what NIH and a meta-analysis found, plus cautions on blood thinners, hormone-sensitive cancers and pregnancy.
Rhaponticum carthamoides, Leuzea carthamoides
Root
Rhaponticum (maral root, Russian leuzea) is a Soviet-era adaptogen herb; this guide covers its ecdysteroids, the very limited human evidence and sports-supplement label problems.
Hippophae rhamnoides
Berry / fruitLeaf
Sea buckthorn (Hippophae rhamnoides): what small trials found for cholesterol, vaginal dryness, dry eye and burns, how oil and cream studies differ, and what safety data we could not find.
Scutellaria lateriflora
Whole plant / above-ground
Skullcap (Scutellaria lateriflora): small studies on mood and sleep, documented liver injury cases and germander adulteration, and why Chinese skullcap is a different plant.
Mentha spicata
Leaf
Spearmint (Mentha spicata): what two small tea trials found for hormone levels in women with excess hair growth, what is unknown, and how it differs from peppermint.
Urtica dioica, Urtica urens
LeafRoot
Stinging nettle (Urtica dioica) leaf and root: what research and EU and NIH sources say about prostate symptoms, allergies and blood sugar, and the cautions for medicines and pregnancy.
Eurycoma longifolia
Root
Tongkat ali (Eurycoma longifolia) is a Southeast Asian root sold for testosterone and vitality. What small trials found, what is unproven, and old reports of metal contamination.
Tribulus terrestris
Berry / fruitWhole plant / above-ground
Tribulus (Tribulus terrestris) is marketed to raise testosterone. What systematic reviews found for testosterone and erectile function, a kidney and liver case report, and doping-test studies.
Arctostaphylos uva-ursi
Leaf
Uva ursi (bearberry leaf, Arctostaphylos uva-ursi): the EU traditional-use monograph, its limits on kidney disease, men, children and pregnancy, and the lack of trials we could read.
Dioscorea villosa
Root
Wild yam (Dioscorea villosa) is sold as a "natural progesterone" cream or supplement. What the sources say about hormones, menopause trials and safety, and what they do not.
Hamamelis virginiana
BarkLeaf
Witch hazel (Hamamelis virginiana): how the distilled water differs from bark and leaf products, what EU and US rules say about skin and hemorrhoid use, and the allergy and oral cautions.
Achillea millefolium
Whole plant / above-groundFlower
Yarrow (Achillea millefolium): what the EU says about its traditional uses for appetite, cramps and small wounds, why daisy-family allergy matters, and cautions for pregnancy and children.
Ocimum tenuiflorum, Ocimum sanctum (synonym)
Leaf
What holy basil or tulsi (Ocimum tenuiflorum) is, how it differs from sweet basil, what small trials found for stress and blood sugar, and the safety gaps that remain.
Berberis aristata, Berberis vulgaris, Coptis chinensis, Hydrastis canadensis, Berberis aquifolium
RootBark
Berberine from Berberis, Coptis and goldenseal plants: what trials found for blood sugar and cholesterol, why newborns and many medicines are a concern, and what is unproven.
Paeonia lactiflora
Root
White peony root (Paeonia lactiflora, Bai shao): what European regulators and trial reviews found, why there is no EU monograph, and pregnancy and medicine cautions.
Plantago ovata
Seed
Psyllium seed husk (Plantago ovata): what trials and EU regulators say about constipation, IBS and cholesterol, plus choking, allergy, medicine-timing and pregnancy cautions.
Moringa oleifera
Leaf
Moringa leaf (Moringa oleifera): what small human trials and reviews found on blood sugar, blood pressure and breast milk, plus pregnancy, medicine and allergy cautions.
Commiphora myrrha, Commiphora molmol
Resin
Myrrh resin (Commiphora myrrha): what the EU says about mouth and skin use, what small trials found, and warfarin, pregnancy, allergy and quality cautions.
Euterpe oleracea
Berry / fruit
Acai fruit (Euterpe oleracea): what NIH says about the very limited human research, weight-loss marketing, raw-juice Chagas risk, blood sugar and MRI cautions.
Eucalyptus globulus
Leaf
Eucalyptus leaf and leaf oil (Eucalyptus globulus): why swallowing the oil is dangerous, what EU regulators and trials say about cough and colds, and cautions for children and pregnancy.
Cucurbita pepo
Seed
Pumpkin seed and seed oil (Cucurbita pepo): the EU traditional-use status for urinary symptoms, what prostate and other trials found, and allergy and pregnancy cautions.
Garcinia mangostana
Berry / fruit
Mangosteen fruit rind (Garcinia mangostana): what the sources say about gum, blood sugar and other uses, plus cautions on medicines, cancer treatment, kidney disease and diabetes.
Adansonia digitata
Berry / fruit
Baobab fruit pulp powder (Adansonia digitata): what the few human trials found on blood sugar and iron, what regulators allow as a food ingredient, and what is unknown about safety.
Piper methysticum
Root
Kava root (Piper methysticum): rare but serious liver injury, bans in several countries, mixed trial results for anxiety, and sedative, alcohol and pregnancy cautions.
Artemisia vulgaris
Whole plant / above-ground
Mugwort (Artemisia vulgaris) herb: traditional uses, what little human research exists, the Cochrane review of mugwort moxibustion for breech babies, and pregnancy and allergy cautions.
Artemisia absinthium
Whole plant / above-ground
Wormwood (Artemisia absinthium), the bitter herb behind absinthe: what EU regulators and small trials say, plus thujone, seizure, liver, pregnancy and sweet wormwood cautions.
Smilax ornata, Smilax regelii (synonym of S. ornata per GBIF), Smilax aristolochiifolia, Smilax glabra (tu fu ling)
Root
Sarsaparilla root (Smilax species): what we could and could not verify about psoriasis and gout claims, plus kidney, pregnancy, digoxin and lithium cautions.
Angelica archangelica
Root
European angelica root (Angelica archangelica): what the sources say about digestive use, the sun-sensitivity risk from furanocoumarins, and why it is not the same as dong quai.
Nymphaea caerulea
Flower
Blue lotus flower (Nymphaea caerulea): no good human trials, psychoactive alkaloids that vary by product, reports of confusion after vaping, and unclear legal status.
Alpinia galanga
Rhizome
Galangal rhizome (Alpinia galanga): a Southeast Asian spice with little human research, a few small trials, and unanswered questions on medicines, pregnancy and safety.
Lobelia inflata
Whole plant / above-ground
Lobelia (Lobelia inflata, "Indian tobacco"): why it carries a poisoning risk from lobeline, what the Cochrane review found on quitting smoking, and what is not proven.
Turnera diffusa
Leaf
Damiana leaf (Turnera diffusa): traditional use as an aphrodisiac and tonic, the small human studies we could read, and cautions on medicines, pregnancy and blood sugar.
Verbena hastata
Whole plant / above-ground
Blue vervain (Verbena hastata): a North American plant used in folk medicine for nerves and sleep, with no human trials found and little modern safety testing.
Terminalia arjuna
Bark
Arjuna bark (Terminalia arjuna): what small heart-health trials found, what is unclear, and cautions on heart medicines, pregnancy, allergy and heavy-metal contamination.
Citrus aurantium
Berry / fruit
Bitter orange (Citrus aurantium) peel and synephrine supplements: heart rhythm and blood pressure warnings, what weight-loss trials found, label problems, and who should ask first.
Viburnum prunifolium
Bark
Black haw bark (Viburnum prunifolium): a traditional uterine herb with almost no modern human research, plus pregnancy, aspirin-allergy, kidney-stone and blood-thinner cautions.
Viburnum opulus
Bark
Cramp bark (Viburnum opulus) is used traditionally for period and muscle cramps, but the sources we read found no human trials and too little safety data to judge it.
Eclipta prostrata
Leaf
Bhringraj (Eclipta prostrata), an Ayurvedic leaf herb used in hair oils: what the sources say about hair and liver claims, and why human evidence is still very thin.
Caulophyllum thalictroides
Root
Blue cohosh root (Caulophyllum thalictroides): why it is linked to heart and stroke harms in newborns when used for labor, what research exists, and how it differs from black cohosh.
Salvia hispanica
Seed
Chia seed (Salvia hispanica): what trials found on blood pressure, cholesterol and weight, and why dry seeds can block the throat, plus allergy and medicine cautions.
Coriandrum sativum
Leaf
Cilantro (Coriandrum sativum leaf): why the heavy-metal "detox" claim lacks human proof, real food-safety risks such as Cyclospora and lead, allergy, and the thin research.
Asparagus racemosus
Root
Shatavari root (Asparagus racemosus): what small trials and reviews show for lactation, menopause and women's health, and what is not yet known about safety.
Ilex paraguariensis
Leaf
Yerba mate leaf (Ilex paraguariensis): caffeine content, what IARC says about very hot drinks and esophageal cancer, what trials found, and EU cautions on pregnancy and heart conditions.
Paullinia cupana
Seed
Guarana seed (Paullinia cupana): a caffeine-rich herb. What research shows on focus and fatigue, and cautions for the heart, blood pressure, pregnancy, children and surgery.
Aspalathus linearis
Leaf
Rooibos leaf (Aspalathus linearis), red and green: what small human studies show, plus liver-case, transplant-drug, chemotherapy and hormone-sensitive-cancer cautions.
Epimedium sagittatum, Epimedium brevicornum, Epimedium grandiflorum
Leaf
Horny goat weed (Epimedium, yin yang huo): what sources say about bone loss and sexual health claims, plus heart, hormone-sensitive cancer, liver and medicine cautions.
Lactuca virosa
Whole plant / above-ground
Wild lettuce (Lactuca virosa), sometimes sold as "lettuce opium": what the sources say about sleep and pain claims, the poisoning case reports, and why human evidence is missing.
Linum usitatissimum
Seed
Flaxseed (Linum usitatissimum): what regulators and trials say about constipation, cholesterol and hot flashes, plus choking, hormone, pregnancy and medicine cautions.
Terminalia chebula, Terminalia bellirica, Phyllanthus emblica
Berry / fruit
Triphala is an Ayurvedic blend of three fruits (haritaki, bibhitaki, amla); what trials found on mouthwash, cholesterol and bowels, plus medicine, pregnancy and metal-quality cautions.
Filipendula ulmaria
Flower
Meadowsweet (Filipendula ulmaria): a salicylate-containing flowering herb used in tea for colds and aching joints. Read what EU regulators say, what trials are missing, and the salicylate cautions.
Handroanthus impetiginosus, Tabebuia avellanedae
Bark
Pau d'arco inner bark (Handroanthus impetiginosus): what the few human studies and many lab studies show, plus bleeding, blood-thinner, pregnancy and quality cautions.
Ptychopetalum olacoides
Bark
Muira puama (Ptychopetalum olacoides) bark and root: what the sources say about libido and nerve-tonic claims, how little human safety data exists, and what to ask before using it.
Alchemilla vulgaris, Alchemilla xanthochlora, Alchemilla mollis
Whole plant / above-ground
Lady's mantle (Alchemilla vulgaris): a tannin-rich herb used for diarrhea and women's complaints; what the limited research shows and the cautions to know about.
Capsella bursa-pastoris
Whole plant / above-ground
Shepherd's purse (Capsella bursa-pastoris): what EU regulators and one small trial say about heavy periods, why heavy bleeding needs a doctor, and pregnancy cautions.
Rehmannia glutinosa
Root
Rehmannia root (Rehmannia glutinosa, di huang): raw versus prepared forms, what small and mixed-quality trials show, and honest safety gaps on medicines, pregnancy and digestion.
Bupleurum chinense, Bupleurum scorzoneraefolium, Bupleurum falcatum
Root
Bupleurum root (Bupleurum chinense, chai hu): what research shows, why liver-injury and lung reports matter, and what to know about the Xiao Chai Hu Tang formula.
Salvia miltiorrhiza
Root
Danshen (red sage root, Salvia miltiorrhiza): warfarin and blood-thinner bleeding warnings first, then what trials of danshen pills found for angina and what is unproven.
Forsythia suspensa
Berry / fruit
Forsythia fruit (Forsythia suspensa, lian qiao): what human trials, lab studies and traditional use show for colds and inflammation, plus pregnancy, bleeding and surgery cautions.
Lonicera japonica
Flower
Honeysuckle flower (Lonicera japonica, jin yin hua): what the research shows on COVID-19 add-on use and skin rash, why the berries are not safe, and why species and form matter.
Sceletium tortuosum, Mesembryanthemum tortuosum
Whole plant / above-ground
Kanna (Sceletium tortuosum) is a psychoactive southern African plant sold for mood and stress. Small trials, an antidepressant (SSRI) interaction concern, and legal and quality cautions.
Nardostachys jatamansi
Root
Jatamansi (Nardostachys jatamansi), an Ayurvedic root also called spikenard: little human research, a critically endangered wild plant, and why safety data are thin.
Hyssopus officinalis
Leaf
Hyssop leaf (Hyssopus officinalis): what research shows, why the essential oil is linked to seizures, and cautions for pregnancy, children and epilepsy.
Corydalis yanhusuo
Root
Corydalis yanhusuo tuber (yan hu suo): what is known about pain and sleep claims, plus the liver-injury reports, drowsiness, heart-rhythm and pregnancy cautions to know first.
Cnicus benedictus
Whole plant / above-ground
Blessed thistle (Cnicus benedictus): what EU regulators say about its traditional use for poor appetite and indigestion, why no trials exist, and daisy-family allergy and lactation cautions.
Marrubium vulgare
Whole plant / above-ground
White horehound (Marrubium vulgare): what the EU says about traditional use for cough and indigestion, how little human research exists, and pregnancy, diabetes and kidney cautions.
Euphrasia officinalis
Whole plant / above-ground
Eyebright (Euphrasia officinalis): why EU regulators advise against homemade eye washes, what small trials found for conjunctivitis, and what is unknown about other uses.
Agrimonia eupatoria
Whole plant / above-ground
Agrimony (Agrimonia eupatoria) above-ground parts: EU traditional use for mild diarrhoea, mouth and skin, with no human trials found and pregnancy and children cautions.
Stachys officinalis, Betonica officinalis
Whole plant / above-ground
Wood betony (Stachys officinalis): a traditional European herb for nerves and headaches. We found no human trials, so here is what is known and not known about safety.
Rumex crispus
Root
Yellow dock root (Rumex crispus): a traditional laxative and "blood cleanser" with no human trials found, plus oxalate and kidney stone cautions and a thrombocytopenia case report.
Elymus repens, Agropyron repens
Rhizome
Couch grass rhizome (Elymus repens, also Agropyron repens): what EU regulators say about its traditional use for flushing the urinary tract, the thin evidence, and the cautions.
Zea mays
Flower
Corn silk (Zea mays styles and stigmas): traditional urinary and diuretic use, thin trial evidence on blood pressure and blood sugar, and cautions for kidney disease, water pills and pregnancy.
Agathosma betulina, Barosma betulina
Leaf
Buchu leaf (Agathosma betulina): a South African herb long used for urinary complaints, why a German expert panel did not recommend it, and the liver, pregnancy and quality cautions.
Fucus vesiculosus
Whole plant / above-ground
Bladderwrack (Fucus vesiculosus), a brown seaweed: why its iodine can disturb the thyroid, the arsenic and heavy-metal concern, and what EU regulators and trials say about weight-loss claims.
Pueraria montana var. lobata, Pueraria lobata
Root
Kudzu root (ge gen, Pueraria montana var. lobata): small trials on alcohol drinking and menopause, plus estrogen-like activity, tamoxifen, methotrexate and liver or kidney cautions.
Morus alba
Leaf
White mulberry leaf (Morus alba): what research says about blood sugar after meals, why it can add to diabetes medicines, and what is unknown for pregnancy and surgery.
Ziziphus jujuba
Berry / fruit
Jujube fruit (Ziziphus jujuba, da zao) and the sleep seed suan zao ren: what small trials and reviews found, and the sedative, blood-sugar, surgery and pregnancy cautions.
Scutellaria baicalensis
Root
Baikal skullcap (Scutellaria baicalensis, huang qin) root: liver injury reports, what small human trials and lab studies show, and why it is not American skullcap.
Magnolia officinalis
Bark
Magnolia bark (Magnolia officinalis, hou po): honokiol and magnolol, what small trials of blends found for stress and sleep, and sedative, pregnancy and kidney-case cautions.
Phellodendron amurense, Phellodendron chinense
Bark
Phellodendron bark (Phellodendron amurense, huang bai): what small trials of branded blends found, why its berberine matters for newborns, pregnancy and medicines, and what is unproven.
Coptis chinensis
Rhizome
Coptis (goldthread, huang lian), a berberine-rich root: what trials found for blood sugar, and why newborn jaundice, pregnancy and many medicines call for caution.
Platycodon grandiflorus
Root
Platycodon (balloon flower, jie geng), the root of Platycodon grandiflorus: its use for cough and sore throat, the few small human trials, and the safety gaps to know.
Eucommia ulmoides
Bark
Eucommia bark (Eucommia ulmoides, du zhong): what small blood pressure and bone trials show, what is only lab or animal work, and why safety data in people are thin.
Ligustrum lucidum
Berry / fruit
Ligustrum (glossy privet fruit, nu zhen zi): a Chinese-medicine tonic with very little human research. What sources say about use, safety, pregnancy and plant look-alikes.
Isatis tinctoria, Isatis indigotica
Root
Isatis (ban lan gen, woad root, Isatis tinctoria): what the sources say about colds and flu, the thin human evidence, and medicine, pregnancy and Qing Dai cautions.
Atractylodes macrocephala
Rhizome
Atractylodes macrocephala rhizome (bai zhu): how it is used in Chinese formulas for digestion, what the few human studies show, and cautions on pregnancy and daisy-family allergy.
Opuntia ficus-indica
Berry / fruit
Prickly pear (nopal), Opuntia ficus-indica: what small human studies found for blood sugar, cholesterol and bowel symptoms, plus diabetes-medicine, skin and home-canning cautions.
Myrciaria dubia
Berry / fruit
Camu camu fruit (Myrciaria dubia): how much vitamin C it holds, what the few small human studies found, and the vitamin C safety points that still apply to powders and capsules.
Annona muricata
Leaf
Graviola or soursop (Annona muricata): why cancer claims are unproven in people, and the nerve-toxicity and parkinsonism concerns linked to regular fruit, juice and leaf-tea use.
Phyllanthus niruri
Whole plant / above-ground
Chanca piedra (Phyllanthus niruri): what reviews show for kidney stones and chronic hepatitis B, plus pregnancy, medicine and kidney or liver cautions.
Hoodia gordonii
Stem
Hoodia (Hoodia gordonii) is sold for appetite and weight loss, but the one small human trial found no effect, some worrying changes in blood pressure and tests, and copies are common.
Croton lechleri
Resin
Dragon's blood (sangre de grado) is the red latex of Croton lechleri. See what the prescription drug crofelemer proves, what the raw sap lacks, and key safety cautions.
Ilex guayusa
Leaf
Guayusa leaf (Ilex guayusa): a caffeine-containing Amazonian tea. What traditional use, small trials and lab work show, and the caffeine, pregnancy and blood pressure cautions.
Pfaffia paniculata, Hebanthe erianthos (accepted name per GBIF match)
Root
Suma, or Brazilian ginseng (Pfaffia paniculata): what we found on traditional use, the thin human evidence, the ecdysterone sports claims, and safety unknowns.
Boerhavia diffusa
Root
Punarnava (Boerhavia diffusa), an Ayurvedic root herb used for kidney and water-retention claims: what the sources say, why human evidence is thin, and kidney, pregnancy and quality cautions.
Rubia cordifolia
Root
Manjistha root (Rubia cordifolia, Indian madder): traditional blood and skin herb with almost no human trials, and a safety warning about related madder (Rubia tinctorum) compounds.
Aegle marmelos
Berry / fruit
Bael fruit (Aegle marmelos): traditional Ayurvedic digestive and blood-sugar use, what little human research exists, and cautions with diabetes medicines and supplements.
Picrorhiza kurroa
Root
Kutki root (Picrorhiza kurroa), a bitter Ayurvedic herb sold for the liver: what the few small trials show, pregnancy caution, endangered wild stocks and quality concerns.
Saraca asoca
Bark
Ashoka bark (Saraca asoca): an Ayurvedic tree bark used for menstrual problems, with very little human research, a threatened wild supply, and a known look-alike bark sold in its place.
Piper longum
Berry / fruit
Long pepper, or pippali (Piper longum): its piperine content, why it may change how medicines are absorbed, and the near-absence of human trials on the fruit itself.
Trachyspermum ammi
Seed
Ajwain, or carom seed (Trachyspermum ammi): what small trials and lab studies show, why its thymol-rich oil needs care, and what we could not verify on pregnancy and medicines.
Rosa damascena, Rosa x damascena Mill.
Flower
Rose petals (Rosa damascena): what the EU says about the traditional mouth and skin use, what small trials found for constipation and calming scent, and the pregnancy and allergy cautions.
Chrysanthemum morifolium
Flower
Chrysanthemum flower (Chrysanthemum morifolium, ju hua tea): traditional use in Chinese dietary medicine, the very thin human research, and the daisy-family allergy caution.
Ligusticum porteri
Root
Osha root (Ligusticum porteri), also called bear root: what is known about colds and coughs, why no human trials exist, the deadly hemlock look-alike, and wild-harvest concerns.
Eupatorium perfoliatum
Whole plant / above-ground
Boneset (Eupatorium perfoliatum): a fever and cold herb of North American tradition. Lab tests found liver-toxic pyrrolizidine alkaloids in it, and human trials are missing or weak.
Tussilago farfara
Leaf
Coltsfoot leaf (Tussilago farfara) has been used for coughs, but it can contain liver-toxic pyrrolizidine alkaloids. What EU, EFSA and research sources say, and why the evidence for benefit is thin.
Mentha pulegium, Hedeoma pulegioides (American pennyroyal)
Whole plant / above-ground
Pennyroyal (Mentha pulegium and American pennyroyal): why swallowing the oil or herb has caused liver failure and deaths, including infants and abortion attempts, and what research shows.
Ruta graveolens
Whole plant / above-ground
Rue (Ruta graveolens): why this garden herb can burn skin in sunlight and has caused severe poisoning and deaths when swallowed to end a pregnancy, and what little research exists.
Tanacetum vulgare
Whole plant / above-ground
Tansy (Tanacetum vulgare): a thujone-containing plant that sources call unsafe to swallow, with no proven medical benefit, plus pregnancy, seizure and allergy cautions.
Santalum album
Stem
Sandalwood heartwood and oil (Santalum album): what small studies found for calm, skin and warts, why the oil is not for swallowing, skin allergy, fake oils and overharvesting.
Pausinystalia johimbe
Bark
Yohimbe bark (Pausinystalia johimbe): what research and health agencies say about sexual-health and weight-loss claims, plus heart, blood pressure, anxiety and label-accuracy warnings.
Mitragyna speciosa
Leaf
Kratom leaf (Mitragyna speciosa) acts on opioid receptors. What FDA, NIH, WHO and poison-center data say about dependence, deaths, liver injury, 7-OH products and legal status.
Rheum palmatum, Rheum officinale
Root
Rhubarb root (Rheum palmatum, da huang) is a stimulant laxative: what EU and US sources say, why the leaves of garden rhubarb are poisonous, and kidney and pregnancy cautions.
Siraitia grosvenorii
Berry / fruit
Monk fruit (Siraitia grosvenorii, luo han guo): what the FDA and EFSA say about its sweet extract, what little human research exists on blood sugar, and who should ask first.
Garcinia gummi-gutta, Garcinia cambogia
Berry / fruit
Garcinia cambogia fruit rind (Garcinia gummi-gutta): what weight-loss trials found, and why liver-injury reports, a USP caution and NCCIH safety warnings matter before use.
Mucuna pruriens
Seed
Mucuna pruriens (velvet bean) seed is a natural source of levodopa. What Parkinson's trials show, and the medicine, psychiatric, seed-hair and fertility-claim cautions.
Coffea arabica, Coffea canephora
Seed
Green (unroasted) coffee bean extract: the retracted weight-loss study behind the hype, what later trials found, and caffeine, medicine, pregnancy and heart cautions.
Phaseolus vulgaris
Seed
White kidney bean extract (Phaseolus vulgaris), sold as a "starch blocker": what trials show about small weight changes, and why raw or undercooked kidney beans are poisonous.
Irvingia gabonensis
Seed
Irvingia (African mango seed, Irvingia gabonensis): what weight-loss and cholesterol trials show, why their quality is questioned, and blood sugar, kidney and pregnancy cautions.
Citrus bergamia
Berry / fruit
Bergamot fruit (Citrus bergamia): what trials of bergamot extract found for cholesterol, why the oil makes skin sun-sensitive, and the medicine, pregnancy and Earl Grey cautions.
Griffonia simplicifolia
Seed
Griffonia seed (Griffonia simplicifolia) is the commercial source of 5-HTP. What research shows for low mood, and why antidepressant, surgery and contamination cautions come first.
Fadogia agrestis, Vangueria agrestis (accepted name per GBIF)
Stem
Fadogia agrestis stem: popular online as a testosterone booster, yet the sources we read show only rat studies, signs of organ stress in those animals, and no human trials.
Trichilia catigua
Bark
Catuaba bark (Trichilia catigua and look-alike plants sold under the same name): what the lab research shows, why products are often mixed up, and safety cautions.
Artemisia annua
Whole plant / above-ground
Sweet wormwood (Artemisia annua), the plant behind artemisinin: why WHO does not support the plant or its tea for malaria, plus liver, resistance, pregnancy and look-alike cautions.
Cinchona officinalis, Cinchona pubescens, Cinchona calisaya
Bark
Cinchona bark (Cinchona officinalis and relatives), the source of quinine: why it is a risky herb, what quinine warnings say, and what research shows about malaria and leg cramps.
Digitalis purpurea
Leaf
Foxglove (Digitalis purpurea) is a poisonous garden plant, not a herbal remedy. Why every part can harm the heart, how it gets mistaken for comfrey, and who to call.
Areca catechu
Seed
Betel nut (areca nut, Areca catechu): why health agencies link chewing it to oral cancer, mouth scarring and dependence, with pregnancy and medicine cautions. Information only.
Cola nitida
Seed
Kola nut seed (Cola nitida): a caffeine-containing West African chewing seed. What the EU assessment found, why trials are missing, and cautions for pregnancy, children, ulcers and the heart.
Carthamus tinctorius
Flower
Safflower flower (Carthamus tinctorius, hong hua): what is known about its use in Chinese medicine, the thin human evidence, and bleeding, pregnancy and allergy cautions.
Polygala tenuifolia
Root
Polygala root (yuan zhi, Polygala tenuifolia): what reviews say about memory and sleep claims, saponin stomach and throat irritation, pregnancy cautions and look-alike species.
Gastrodia elata
Rhizome
Gastrodia (tian ma, Gastrodia elata) is an orchid tuber used in Chinese medicine for headache and dizziness; the human trials we found tested the isolated compound gastrodin, and safety data are thin.
Uncaria rhynchophylla
Stem
Uncaria (gou teng, Uncaria rhynchophylla): a Chinese medicine hooked stem tied to blood pressure formulas. What trials show, why it is not cat's claw, and medicine cautions.
Ligusticum chuanxiong, Ligusticum striatum
Rhizome
Chuanxiong rhizome (Ligusticum chuanxiong), a Chinese herb used for headache and circulation: what trials show, blood-thinner and pregnancy cautions, and what is not proven.
Houttuynia cordata
Whole plant / above-ground
Houttuynia (Houttuynia cordata, fish mint, yu xing cao): a leafy herb eaten in parts of Asia, with serious allergic reactions reported to its injection and little human research on teas or capsules.
Imperata cylindrica
Rhizome
Imperata (bai mao gen, cogongrass rhizome): traditional use for bleeding and urination, a small human diuretic trial that found no effect, and cautions on potassium, kidneys and quality.
Ophiopogon japonicus
Root
Ophiopogon (mai dong, Ophiopogon japonicus): traditional Chinese use for dry cough and the heart, what trials of Shenmai products really show, and cautions about injections and look-alike roots.
Polygonatum sibiricum, Polygonatum kingianum, Polygonatum cyrtonema
Rhizome
Polygonatum rhizome (huang jing, Solomon's seal; Polygonatum sibiricum): used in Chinese medicine for centuries, with one small sleep trial and mostly lab research behind it.
Dendrobium officinale
Stem
Dendrobium (shi hu, Dendrobium officinale) is an orchid stem used in Chinese medicine; human evidence is small, products are often mixed with other species, and wild plants are threatened.
Alisma orientale, Alisma plantago-aquatica subsp. orientale
Rhizome
Alisma (ze xie, water plantain rhizome): a Chinese medicine herb used as a diuretic and for blood fats. See what research shows, kidney cautions and quality issues.
Coix lacryma-jobi
Seed
Job's tears or coix seed (Coix lacryma-jobi, yi yi ren): what trials and reviews found, why kanglaite injection is a different product, and pregnancy, blood sugar and mold cautions.
Dioscorea polystachya
Root
Chinese yam (shan yao, Dioscorea polystachya): a food and traditional East Asian tonic. What the sources say about digestion and blood sugar (mostly animal work), and what is not known about safety.
Saposhnikovia divaricata
Root
Saposhnikovia root (fang feng, Saposhnikovia divaricata): a Chinese-medicine root known from Yu Ping Feng San, with sun-sensitivity chemistry, look-alike roots and thin human evidence.
Acorus calamus
Rhizome
Calamus or sweet flag (Acorus calamus) rhizome: animal studies link its asarone to liver cancer, US law bars it from food, and human evidence of benefit is missing.
Justicia adhatoda, Adhatoda vasica
Leaf
Vasaka leaf (Justicia adhatoda, also called Adhatoda vasica): traditional cough remedy and source plant of bromhexine, with pregnancy and uterine-stimulant cautions and little human evidence.
Chlorophytum borivilianum
Root
Safed musli root (Chlorophytum borivilianum): Ayurvedic use for stamina and libido, the few small human trials, wild-stock decline, look-alike roots and what is not known about safety.
Vitex negundo
Leaf
Nirgundi (Vitex negundo), the Chinese chaste tree leaf used in Ayurveda for joint pain: what the few human trials found, skin-reaction and pregnancy cautions, and how it differs from chasteberry.
Sida cordifolia
Root
Bala (country mallow, Sida cordifolia): a plant the FDA names as a source of ephedrine, the stimulant banned in US supplements. What the sources say about heart risk, quality and evidence.
Convolvulus prostratus, Convolvulus pluricaulis
Whole plant / above-ground
Shankhpushpi (Convolvulus prostratus, also called C. pluricaulis) in Ayurveda: one small human trial, mostly lab and animal findings, and why products may hold other plants.
Pueraria tuberosa
Root
Vidari kanda (Indian kudzu, Pueraria tuberosa) tuber: what Ayurveda uses it for, what little human research exists, and cautions on hormones, pregnancy and look-alikes.
Garcinia indica
Berry / fruit
Kokum (Garcinia indica), the sour Indian fruit rind and seed butter: what is known about garcinol and HCA, why human evidence is thin, and the liver caution borrowed from Garcinia cambogia.
Eriodictyon californicum
Leaf
Yerba santa leaf (Eriodictyon californicum): a California plant used traditionally for coughs and colds and as a flavoring, with almost no human research and unclear safety data.
Prunella vulgaris
Whole plant / above-ground
Self-heal (Prunella vulgaris, xia ku cao): traditional use for thyroid swelling and cold sores, what trials and lab studies show, and the cautions that apply.
Lycopus virginicus, Lycopus europaeus
Whole plant / above-ground
Bugleweed (Lycopus virginicus, also L. europaeus) is promoted for an overactive thyroid. Read what little human research exists and why thyroid medicines and scans matter.
Prunus serotina
Bark
Wild cherry bark (Prunus serotina) in cough syrups: why the plant contains cyanide-releasing compounds, how thin the human evidence is, and cautions for pregnancy, children and medicines.
Asclepias tuberosa
Root
Pleurisy root (Asclepias tuberosa, butterfly weed): a traditional chest herb with no human trials, cardiac glycoside and heart-medicine cautions, pregnancy warnings and milkweed look-alikes.
Myrica cerifera
Bark
Bayberry or wax myrtle (Myrica cerifera) root bark: no good evidence it works, and consumer references warn about liver, cancer-risk and blood pressure concerns.
Usnea barbata
Whole plant / above-ground
Usnea (old man's beard lichen, Usnea barbata) contains usnic acid, linked to serious liver injury and liver failure in weight-loss products; what the sources say and why caution matters.
Malva sylvestris
Flower
Common mallow (Malva sylvestris): what the EU herbal committee says about flower and leaf teas for throat irritation, the single small constipation trial, and cautions for pregnancy and children.
Viola tricolor
Whole plant / above-ground
Heartsease or wild pansy (Viola tricolor): an EU traditional herbal tea and skin wash for mild seborrhoeic skin conditions, with no human trials found and clear cautions.
Betula pendula, Betula pubescens
Leaf
Birch leaf (Betula pendula, B. pubescens): what EU regulators say about its traditional use for urinary flushing, plus pollen-allergy, fluid, heart, kidney and pregnancy cautions.
Galega officinalis
Whole plant / above-ground
Goat's rue (Galega officinalis): the plant that led to metformin, why it can lower blood sugar and poison livestock, and what is known about its use for milk supply.
Centaurium erythraea
Whole plant / above-ground
Centaury (Centaurium erythraea), a bitter flowering herb: the EU accepts it only as a traditional medicine for mild indigestion and loss of appetite, with no trials, and warns about ulcers.
Phytolacca americana
Root
Poke root (pokeweed, Phytolacca americana) is a poisonous plant, not a safe herbal remedy. What the sources say about root, berry and leaf poisoning, and who to call.
Pulmonaria officinalis
Whole plant / above-ground
Lungwort (Pulmonaria officinalis) is an old cough herb named for its lung-shaped leaves. See what the sources say, why human evidence is missing, and the open liver-alkaloid question.
Albizia julibrissin
Bark
Albizia (mimosa tree bark, he huan pi): a Chinese calming herb with no human trials in the sources we read, plus sedative, pregnancy and surgery cautions.
Terminalia chebula
Berry / fruit
Haritaki (Terminalia chebula fruit), one of the three fruits of triphala: what the few small human trials found, plus medicine, diabetes, pregnancy and product-quality cautions.
Terminalia bellirica
Berry / fruit
Bibhitaki (Terminalia bellirica, bahera) is one of the three fruits of triphala; what the sources say about evidence, blood sugar, pregnancy, surgery and product quality.
Rauvolfia serpentina
Root
Sarpagandha (Indian snakeroot, Rauvolfia serpentina) is the plant source of reserpine: what sources say about blood pressure, depression, cancer worries, pregnancy and a threatened wild plant.
Celastrus paniculatus
Seed
Malkangani or intellect tree (Celastrus paniculatus, jyotishmati): memory claims rest on animal studies, no human trial results found, and human safety data are missing.
Valeriana wallichii, Valeriana jatamansi
Root
Tagara (Indian valerian, Valeriana wallichii): an Ayurvedic calming root. What small trials and reviews show, why sedation and sourcing matter, and what is known about its safety.
Cyperus rotundus
Rhizome
Nut grass rhizome (Cyperus rotundus; mustaka, xiang fu): traditional menstrual and digestive use, one small weight trial, what is unknown about safety, and a garden weed.
Ferula assa-foetida
Resin
Asafoetida (hing), the resin of Ferula assa-foetida: a serious infant blood-oxygen warning, what small trials show for indigestion and IBS, and what we could not verify.
Solanum virginianum, Solanum xanthocarpum, Solanum surattense
Whole plant / above-ground
Kantakari, the yellow-berried nightshade (Solanum virginianum): its Ayurvedic cough and asthma use, the one small human trial found, and why a nightshade with glycoalkaloids needs care.
Plumbago zeylanica
Root
Chitrak (Plumbago zeylanica), an Ayurvedic root: what the sources say about its toxic plumbagin, skin irritation, pregnancy, liver and kidney cautions, and the lack of human trials.
Holarrhena antidysenterica, Holarrhena pubescens
Bark
Kutaja or kurchi bark (Holarrhena antidysenterica, accepted name H. pubescens): Ayurvedic use for dysentery and diarrhoea, thin human evidence, animal toxicity signals and look-alike bark.
Symplocos racemosa
Bark
Lodhra bark (Symplocos racemosa): an Ayurvedic bark used for periods, PCOS and uterine complaints, with almost no human research, mixed-formula trials only, and look-alike barks sold as substitutes.
Psoralea corylifolia, Cullen corylifolium
Seed
Bakuchi or babchi seed (Psoralea corylifolia, bu gu zhi): skin-sensitising psoralens, vitiligo use with little proof, and published liver injury case reports.
Cuscuta chinensis
Seed
Cuscuta seed (tu si zi, Chinese dodder seed, Cuscuta chinensis): traditional kidney and fertility use, what a 2025 review found, and why pregnancy and medicine cautions matter.
Morinda officinalis
Root
Morinda root (ba ji tian, Morinda officinalis): what research says about bone and mood use, why it is not noni, and what is unknown about liver, laxative and drug-interaction risks.
Achyranthes bidentata
Root
Achyranthes root (niu xi, Achyranthes bidentata): what the sources say about joints and bones, why pregnancy caution matters, and how it differs from Cyathula.
Dipsacus asper, Dipsacus asperoides
Root
Dipsacus root (Dipsacus asper, xu duan, Japanese teasel): traditional bone and tendon use, why human fracture and osteoporosis evidence is missing, and how it differs from Lyme teasel.
Paeonia suffruticosa, Paeonia x suffruticosa Andrews
Bark
Moutan, the root bark of tree peony (Paeonia suffruticosa, mu dan pi): what reviews say about its evidence, why it is not white peony, and pregnancy and heavy-period cautions.
Gardenia jasminoides
Berry / fruit
Gardenia fruit (zhi zi, Gardenia jasminoides): what is known about traditional use, the thin human evidence, liver cautions from animal studies, and its use as a natural food colour.
Angelica dahurica
Root
Angelica dahurica (bai zhi) root: traditional use for headache and stuffy nose, what research does and does not show, and sun-sensitivity, pregnancy and medicine cautions.
Angelica pubescens, Angelica biserrata
Root
Angelica pubescens root (du huo): its traditional use for joint pain, the thin human evidence, and the sun-sensitivity, poisoning and pregnancy cautions to know first.
Notopterygium incisum, Notopterygium franchetii, Hansenia weberbaueriana (GBIF accepted name for N. incisum)
Root
Notopterygium (qiang huo) root: its traditional use for upper-body joint pain and colds, the lack of human trials, a possible drug-interaction signal, and concerns about endangered wild stock.
Xanthium sibiricum, Xanthium strumarium
Berry / fruit
Xanthium fruit (cang er zi, cocklebur, Xanthium sibiricum) is used in Chinese medicine for nasal complaints, but it contains liver-toxic compounds and has been linked to organ failure and death.
Pinellia ternata
Rhizome
Pinellia (ban xia, Pinellia ternata): a Chinese-medicine tuber used for nausea and phlegm, toxic when raw, with processing, pregnancy and quality cautions and little human trial data.
Citrus reticulata
Berry / fruit
Tangerine peel (chen pi, Citrus reticulata): what we found on digestion and flavonoid research, mold in aged peel, and why strong claims are not yet backed by good human trials.
Nelumbo nucifera
Seed
Lotus seed (lian zi, Nelumbo nucifera) and its green core: traditional use for sleep and loose stools, one small unblinded sleep pilot, mostly lab research, and constipation and mold cautions.
Prunus armeniaca
Seed
Apricot kernel (Prunus armeniaca): why raw kernels can cause cyanide poisoning, what "vitamin B17" and laetrile really are, and what EFSA, the FDA and Cochrane found.
Alpinia oxyphylla
Berry / fruit
Alpinia oxyphylla fruit (yi zhi ren, bitter cardamom): used in Chinese medicine for urinary frequency and diarrhoea, with lab studies on the brain but no human trials found.
Asparagus cochinchinensis
Root
Chinese asparagus root (tian men dong, Asparagus cochinchinensis): its traditional use for dry cough, why human evidence is missing, and cautions on drug enzymes and look-alike roots.
Vitis vinifera
Seed
Grape seed extract (Vitis vinifera): what reviews found for blood pressure and cholesterol, what is only lab work, and the blood-thinner, medicine and pregnancy cautions.
Medicago sativa
Leaf
Alfalfa (Medicago sativa) leaf, sprouts and seeds: what sources say about cholesterol, plus lupus flare, sprout food-poisoning, warfarin, estrogen-like and pregnancy cautions.
Chondrus crispus
Whole plant / above-ground
Irish moss or sea moss (Chondrus crispus): what we found on iodine, heavy metals, carrageenan and thyroid cautions, and why the popular sea moss gel claims are not backed by human trials.
Saccharina japonica, Ascophyllum nodosum
Whole plant / above-ground
Kelp (Saccharina japonica, also Ascophyllum nodosum), a brown seaweed: why its iodine can upset the thyroid, the arsenic concern, and how little human evidence supports health claims.
Arthrospira platensis
Whole plant / above-ground
Spirulina (Arthrospira platensis), a blue-green alga sold as powder and tablets: what trials show for cholesterol and blood pressure, plus contamination, allergy and B12 cautions.
Chlorella vulgaris, Chlorella pyrenoidosa
Whole plant / above-ground
Chlorella (Chlorella vulgaris), a green microalga sold as tablets and powder: what trials found, plus vitamin K and warfarin, allergy, contamination and immune-condition cautions.
Triticum aestivum
Leaf
Wheatgrass (Triticum aestivum) young-leaf juice and powder: what small trials in ulcerative colitis show, plus gluten, raw-juice contamination and nausea cautions.
Chamaelirium luteum
Root
False unicorn root (Chamaelirium luteum): a threatened North American plant used traditionally for menstrual and fertility concerns, with almost no human research and real pregnancy and sourcing cautions.
Mitchella repens
Whole plant / above-ground
Partridgeberry (Mitchella repens) is a traditional late-pregnancy and labor herb. The only study we found was in mouse tissue; there are no human trials, and pregnancy safety is unproven.
Thuja occidentalis
Leaf
Thuja (northern white cedar, Thuja occidentalis): thujone toxicity, why it is avoided in pregnancy, what is known about warts and coughs, and Echinacea-thuja products.
Collinsonia canadensis
Root
Stone root (Collinsonia canadensis): old uses for hemorrhoids, varicose veins and kidney stones, why no human trials were found, and the thin safety information.
Hydrangea arborescens
Root
Hydrangea root (Hydrangea arborescens): traditionally used for kidney and bladder stones, with no human trials found, plus a cyanide-type compound, lithium and pregnancy cautions.
Eutrochium purpureum, Eupatorium purpureum (older name)
Root
Gravel root (Joe-Pye weed, Eutrochium purpureum): an old urinary-stone remedy from North America. Liver-toxic alkaloid risk is likely, and proper human evidence was not found.
Iris versicolor
Root
Blue flag rhizome (Iris versicolor): a wetland iris whose root is irritating and can cause vomiting, with no good human trials behind its traditional skin and lymph uses.
Orthosiphon aristatus, Orthosiphon stamineus (older name used in earlier EU monograph and ESCOP)
Leaf
Java tea (cat's whiskers, Orthosiphon aristatus): what EU regulators and trials say about urinary flushing, plus the heart and kidney fluid warning, pregnancy and potassium notes.
Leonotis leonurus
Leaf
Lion's tail or wild dagga (Leonotis leonurus), a South African plant smoked or brewed as tea: traditional use, no human trials found, rat toxicity findings, and look-alike warnings.
Garcinia kola
Seed
Bitter kola seed (Garcinia kola): a West African chewed seed used for cough and liver complaints. What the few human trials and many animal studies show, and the safety gaps.
Hypoxis hemerocallidea
Root
African potato corm (Hypoxis hemerocallidea): traditional immune tonic with no proven benefit for HIV or prostate; what reviews show, plus antiretroviral interaction and safety cautions.
Cyclopia intermedia, Cyclopia subternata, Cyclopia genistoides
Leaf
Honeybush (Cyclopia species) is a South African tea. See what reviews and lab work report on mangiferin and plant oestrogens, and why human evidence is thin.
Smallanthus sonchifolius
Root
Yacon (Smallanthus sonchifolius): what trials of the root syrup and flour show for blood sugar, weight and bowels, what is unproven for the leaf tea, and cautions.
Angelica keiskei
Leaf
Ashitaba (Angelica keiskei): what EFSA and human trials say about the leaf, stem sap and chalcones, plus cautions on blood clotting, pregnancy, allergy and look-alike Angelica herbs.
Lessertia frutescens, Sutherlandia frutescens
Whole plant / above-ground
Sutherlandia (cancer bush, Lessertia frutescens): what small human trials and lab studies show, and why antiretroviral and tuberculosis-prevention medicine interactions matter.
Psidium guajava
Leaf
Guava leaf (Psidium guajava) as tea or extract: what small trials and reviews say about diarrhoea and blood sugar, and what is still unknown about safety and medicine interactions.
Carica papaya
Leaf
Papaya leaf (Carica papaya): small dengue trials report higher platelet counts, but reviews say proof is weak; pregnancy, liver, diabetes-medicine and latex-allergy cautions.
Avena sativa
Whole plant / above-ground
Oat straw and milky oats (Avena sativa): what the EU says about traditional use for stress and sleep, small trials of green oat extract on thinking, and gluten questions for celiac disease.
Viscum album
Whole plant / above-ground
European mistletoe (Viscum album): why the leaves, berries and teas can poison, what research says about injected extracts such as Iscador in cancer care, and who needs medical advice.
Chelidonium majus
Whole plant / above-ground
Greater celandine (Chelidonium majus): why EU regulators call oral use a negative benefit-risk, the liver injury reports, the wart latex tradition, and a not-lesser-celandine warning.
Larrea tridentata
Leaf
Chaparral (creosote bush, Larrea tridentata): reports of serious liver injury, no proven benefit, and what the sources say about tea, capsules, tinctures and skin products.
Sassafras albidum
Bark
Sassafras (Sassafras albidum): why root bark and oil carry a cancer warning because of safrole, the US food ban, safrole-free extract, and how filé powder from leaves differs.
Peumus boldus
Leaf
Boldo leaf (Peumus boldus): what EU regulators say about its traditional use for indigestion, plus liver, gallstone, pregnancy and ascaridole safety cautions.
Dysphania ambrosioides
Whole plant / above-ground
Epazote (Dysphania ambrosioides): the Mexican cooking herb versus wormseed oil and strong infusions, which have caused child deaths. Evidence, pregnancy and safety cautions.
Perilla frutescens
Leaf
Perilla (shiso, su ye) leaf, Perilla frutescens: what small trials and reviews show for hay fever and digestion, plus perilla ketone, allergy and pregnancy cautions.
Reynoutria japonica, Polygonum cuspidatum, Fallopia japonica
Root
Japanese knotweed root (Reynoutria japonica, hu zhang): the main commercial source of resveratrol, also rich in laxative emodin compounds; what the research shows, cautions, and why it is an invasive plant.
Sophora flavescens
Root
Sophora flavescens (ku shen) root contains matrine and oxymatrine; what research says on hepatitis B and skin uses, plus liver and nerve-toxicity cautions.
Tetradium ruticarpum, Evodia rutaecarpa, Euodia rutaecarpa
Berry / fruit
Evodia fruit (wu zhu yu, Tetradium ruticarpum): its traditional use for headache and cold stomach pain, what human evidence exists, and the liver, heart and medicine-interaction cautions.
Agastache rugosa
Whole plant / above-ground
Korean mint (Agastache rugosa, called huo xiang) explained: how it differs from patchouli, what trials of the huo xiang zheng qi formula found, and its estragole and quality cautions.
Fritillaria cirrhosa, Fritillaria thunbergii, Fritillaria ussuriensis
Rhizome
Fritillaria bulb (chuan bei mu, Fritillaria cirrhosa and relatives): its traditional use for cough, why human trial evidence is missing, and aconite, adulteration and wild-harvest cautions.
Lilium brownii, Lilium brownii var. viridulum, Lilium lancifolium, Lilium pumilum
Bulb
Lily bulb (bai he, Lilium brownii and related species): a food-and-medicine bulb in Chinese tradition, what trials and reviews show for sleep and mood, and the cat-toxicity and quality cautions.
Cornus officinalis
Berry / fruit
Cornelian cherry fruit (shan zhu yu, Cornus officinalis): a Chinese-medicine fruit in Liu Wei Di Huang Wan. What human and lab research shows, and which cautions apply.
Amomum villosum, Wurfbainia villosa
Berry / fruit
Amomum fruit (sha ren, Amomum villosum, now Wurfbainia villosa): a Chinese digestive herb; what animal studies show, why pregnancy use rests on tradition only, and cautions.
Kigelia africana
Berry / fruit
Sausage tree (Kigelia africana): an African fruit used in skin creams. What the sources say, why the raw fruit is toxic, and why human trials are missing.
Vernonia amygdalina, Gymnanthemum amygdalinum (accepted name per GBIF)
Leaf
Bitter leaf (Vernonia amygdalina): a West African food and folk remedy. What small human studies and animal work show for malaria and blood sugar, and a serious Ugandan case report.
Cryptolepis sanguinolenta
Root
Cryptolepis (Cryptolepis sanguinolenta), a West African root tea used for malaria: small open studies, lab signs of DNA and cell toxicity, and why it is not a safe replacement for malaria medicine.
Artemisia afra
Whole plant / above-ground
African wormwood (Artemisia afra): a southern African herbal tea plant with no proven use against malaria or COVID-19, what WHO and lab studies say, and the safety questions still open.
Catha edulis
Leaf
Khat leaf (Catha edulis) is an amphetamine-like stimulant chewed in East Africa and Yemen. What the DEA and medical reviews say about dependence, heart, liver and mental-health risks, and legal status.
Maytenus macrocarpa, Maytenus krukovii
Bark
Chuchuhuasi bark (Maytenus macrocarpa and look-alike Amazon trees): traditional use for rheumatism and colds, why no human trials exist, and the safety unknowns.
Mimosa tenuiflora, Mimosa hostilis (older name)
Bark
Tepezcohuite bark (Mimosa tenuiflora): a Mexican skin-healing bark with mixed trial results for leg ulcers, birth-defect warnings in animals, and a DMT-containing, controlled-substance side.
Anemopsis californica
Root
Yerba mansa root (Anemopsis californica): a wetland plant of the American Southwest used in folk medicine, with only lab research behind it, plus habitat-conservation and safety notes.
Salvia apiana
Leaf
White sage (Salvia apiana), a California native: its sacred place for many Native peoples, poaching and habitat loss, smoke and air quality, and what lab studies do and do not show.
Zanthoxylum americanum
Bark
Northern prickly ash bark (Zanthoxylum americanum), the "toothache tree": traditional uses, what lab studies and the few reviews found, and stomach, pregnancy and medicine cautions.
Baptisia tinctoria
Root
Wild indigo root (Baptisia tinctoria): its cytisine-type alkaloids, vomiting at large amounts, pregnancy cautions, and what trials of Echinacea-Baptisia-Thuja cold products show.
Ceanothus americanus
Root
Red root (Ceanothus americanus, New Jersey tea): traditional uses for bleeding, lymph and spleen, what little research exists, and why a possible clotting effect needs care.
Impatiens capensis
Whole plant / above-ground
Jewelweed (Impatiens capensis), a North American wildflower used as a folk poison-ivy remedy: what the small controlled trials found, and cautions about eating it.
Asarum canadense
Rhizome
Wild ginger (Asarum canadense) is not true ginger. Its rhizome can contain aristolochic acid, which the FDA treats as a kidney toxin and carcinogen. See the evidence and cautions.
Podophyllum peltatum
Root
Mayapple (Podophyllum peltatum) is a poisonous woodland plant, not a herbal remedy: its root resin is the source of wart drugs, and poisoning can be severe. Information only.
Sanguinaria canadensis
Root
Bloodroot (Sanguinaria canadensis): why black salve cancer products cause tissue destruction, the FDA warnings, the old mouthwash link to white mouth patches, and what research shows.
Chimaphila umbellata
Leaf
Pipsissewa (prince's pine, Chimaphila umbellata): what we could and could not verify about its folk uses, the lack of human trials, the threatened status of wild plants, and safety cautions.
Geranium maculatum
Root
Cranesbill or wild geranium root (Geranium maculatum): an old tannin-rich astringent for diarrhoea and mouth problems with no good human evidence, and unknown safety.
Verbena officinalis
Whole plant / above-ground
European vervain (Verbena officinalis): the thin human evidence, its role in the five-herb Sinupret sinus product, and the pregnancy, children and alcohol-drops cautions.
Borago officinalis
Whole plant / above-ground
Borage (Borago officinalis): why its leaf and flower carry liver-toxic pyrrolizidine alkaloids, what research says about the seed oil, and the foxglove look-alike and pregnancy cautions.
Levisticum officinale
Root
Lovage root (Levisticum officinale): the 2012 EU traditional-use monograph for urinary flushing, plus sun-sensitivity, kidney, fluid, pregnancy and children cautions, and no trials found.
Tropaeolum majus
Whole plant / above-ground
Garden nasturtium (Tropaeolum majus): a mustard-oil herb tested only in a fixed horseradish combination for bronchitis and cystitis, with stomach, kidney and pregnancy cautions.
Nasturtium officinale
Whole plant / above-ground
Watercress (Nasturtium officinale) as an herb: what small trials of watercress and its compound PEITC found, plus warfarin, liver-fluke, drug-processing and quality cautions.
Cetraria islandica
Whole plant / above-ground
Iceland moss (Cetraria islandica) is a lichen, not a moss, used as a soothing tea or lozenge for dry cough and sore mouth and throat; what EU regulators say, and the lead and radioactivity cautions.
Primula veris
Flower
Cowslip (Primula veris) flower and root: why EU regulators allow it only as a traditional cough remedy, what thyme-primula trials show, and pregnancy, stomach and allergy cautions.
Drosera rotundifolia
Whole plant / above-ground
Sundew (Drosera rotundifolia), a carnivorous bog plant traditionally used for cough and whooping cough: what little research exists, safety cautions, and why wild picking is discouraged.
Melilotus officinalis
Whole plant / above-ground
Sweet clover or melilot (Melilotus officinalis): EU traditional use for heavy legs, thin evidence, and the coumarin issues behind liver and blood-thinner cautions, plus the spoiled-clover story.
Fumaria officinalis
Whole plant / above-ground
Fumitory (Fumaria officinalis): what the EU regulator says about digestive complaints and bile, the one negative IBS trial, and cautions for liver and gallbladder problems.
Ononis spinosa
Root
Restharrow root (Ononis spinosa): the EU traditional use for flushing the urinary tract, why it is not for people told to limit fluids, and what research does and does not show.
Oplopanax horridus
Bark
Devil's club bark (Oplopanax horridus): its place in Pacific Northwest and Alaska Indigenous medicine, why blood-sugar claims are not backed by trials, and diabetes-medicine cautions.
Monarda didyma, Monarda fistulosa
Whole plant / above-ground
Bee balm or Oswego tea (Monarda didyma, also Monarda fistulosa): thin evidence, one small human trial, no agency review, and pregnancy and safety-data gaps explained.
Centaurea cyanus
Flower
Cornflower (Centaurea cyanus), the blue petals in teas and cosmetics: old eye-wash use and why it is a sterility risk, daisy-family allergy, and the thin lab-only evidence.
Aconitum carmichaelii
Root
Aconite (monkshood, Aconitum carmichaelii) is a highly poisonous root: how it harms the heart and nerves, what processing (fuzi) changes, and what research does and does not show.
Nerium oleander
Leaf
Oleander (Nerium oleander) is a poisonous garden shrub, not a herbal remedy. Heart danger from every part, leaf-tea mix-ups, burning smoke, supplement look-alikes, and who to call.
Convallaria majalis
Whole plant / above-ground
Lily of the valley (Convallaria majalis) is a poisonous garden plant with heart-active compounds, not a safe herbal remedy. Symptoms, wild garlic mix-ups and who to call.
Atropa belladonna
Leaf
Belladonna or deadly nightshade (Atropa belladonna) is a poisonous plant, not a safe home remedy. Its dangers, why berries tempt children, and what sources say.
Tripterygium wilfordii
Root
Thunder god vine root (Tripterygium wilfordii): NCCIH and published reviews on rheumatoid arthritis, plus the serious kidney, liver, fertility, immune and birth-defect risks.
Stephania tetrandra
Root
Stephania (fang ji, Stephania tetrandra) root: the mix-up with Aristolochia that caused kidney failure and cancer, what tetrandrine research shows, and what to check before any product.
Saussurea costus, Dolomiaea costus, Saussurea lappa, Aucklandia lappa
Root
Costus root (mu xiang, Saussurea costus): an endangered Himalayan root, a skin allergen, and a name confused with a kidney-toxic plant. What the sources say, and how little human research exists.
Aquilaria malaccensis
Stem
Agarwood, oud or chen xiang (Aquilaria malaccensis): why there are no human trials, what lab and animal studies suggest, smoke and fake-product cautions, and its protected, overharvested status.
Anemarrhena asphodeloides
Rhizome
Anemarrhena (zhi mu, Anemarrhena asphodeloides): a Chinese medicine rhizome whose research is almost all in mice and cells, with no good human safety data.
Senna obtusifolia, Cassia obtusifolia
Seed
Cassia seed (jue ming zi, Senna obtusifolia): a traditional Chinese seed with laxative-type anthraquinones; what human evidence exists, and liver, kidney and pregnancy cautions.
Artemisia capillaris
Whole plant / above-ground
Capillary wormwood (Artemisia capillaris, yin chen hao): its Chinese medicine use for jaundice, what the evidence is, and the liver-injury case reports and allergy cautions to know.
Trichosanthes kirilowii
Root
Trichosanthes root (tian hua fen, Trichosanthes kirilowii): a Chinese medicine root whose protein, trichosanthin, was used to end pregnancies and can cause severe allergic reactions.
Gentiana macrophylla
Root
Qin jiao (large-leaf gentian root, Gentiana macrophylla) is used in Chinese medicine for joint pain; the research we read is animal and lab work, with no human trials found.
Scrophularia nodosa
Whole plant / above-ground
Figwort (Scrophularia nodosa): a traditional skin herb with iridoid compounds, no human trials found, thin safety data and a heart caution from practitioner and older reference sources.
Taxillus chinensis
Stem
Taxillus (sang ji sheng, Taxillus chinensis): a parasitic Chinese mistletoe whose chemistry depends on its host tree. What reviews say, why the host matters for safety, and why human evidence is missing.
Salacia reticulata
Root
Salacia reticulata root and stem: small trials on after-meal blood sugar and HbA1c, the low blood sugar caution with diabetes medicines, stomach effects, and pregnancy warnings.
Pterocarpus marsupium
Bark
Vijaysar (Indian kino, Pterocarpus marsupium) heartwood: its Ayurvedic use for diabetes, the small human studies behind it, and the low blood sugar caution with diabetes medicines.
Syzygium cumini
Seed
Jamun (Java plum) seed, Syzygium cumini: traditional use for diabetes, what small trials found, and why people on diabetes medicines or pregnant should check first.
Hemidesmus indicus
Root
Sariva or Indian sarsaparilla root (Hemidesmus indicus): a traditional Ayurvedic blood and skin herb with lab and animal findings but no human trials found, and unanswered safety questions.
Swertia chirayita
Whole plant / above-ground
Chirata (Swertia chirayita), an intensely bitter Himalayan herb: what is known about its traditional use, why human evidence is thin, and blood-sugar, supply and quality cautions.
Pluchea lanceolata
Leaf
Rasna (Pluchea lanceolata) is an Ayurvedic leaf herb used for joint pain; the human research is small or unfinished, and daisy-family allergy is a reason for care.
Alstonia scholaris
Bark
Saptaparna or devil's tree bark (Alstonia scholaris): its traditional use for malaria and fever, how thin the human evidence is, and cautions for pregnancy, liver and blood.
Calotropis gigantea
Root
Calotropis (arka, Calotropis gigantea) is a toxic plant, not a safe herbal remedy. Heart-poison compounds in all parts, caustic latex that injures the eye, and what research does and does not show.
Cissampelos pareira
Root
Patha (velvetleaf, Cissampelos pareira) root: what the sources say about its alkaloids, traditional uses and very thin human evidence, plus anesthesia and pregnancy cautions.
Woodfordia fruticosa
Flower
Dhataki (fire-flame bush, Woodfordia fruticosa) flowers: Ayurvedic use for menstrual and uterine problems, lab findings on tannins, and why human safety data are missing.
Cissus quadrangularis
Stem
Cissus quadrangularis stem: what small trials show for bone, joints and weight, and the cautions on blood sugar, pregnancy, surgery and unproven hormone claims.
Potentilla erecta
Root
Tormentil rhizome (Potentilla erecta): an EU traditional herbal medicine for mild diarrhoea and mouth inflammation, based on long use and lab work, with no good human trials found.
Potentilla anserina, Argentina anserina
Whole plant / above-ground
Silverweed (Potentilla anserina, now Argentina anserina): a tannin-rich traditional herb for cramps and diarrhea, with thin human evidence and pregnancy and medicine-timing cautions.
Rumex acetosa
Whole plant / above-ground
Common sorrel (Rumex acetosa): oxalic acid cautions for kidney stones and kidney disease, what trials of the five-herb Sinupret mix show for sinus infection, and why the herb alone is unproven.
Cytisus scoparius
Whole plant / above-ground
Scotch broom (Cytisus scoparius): why this alkaloid-containing shrub is listed as likely unsafe by mouth, with pregnancy, heart, blood pressure and MAOI antidepressant cautions.
Calluna vulgaris
Flower
Heather or ling (Calluna vulgaris) is a traditional urinary tea herb that contains arbutin. We found no human trials, no EU herbal monograph, and only lab studies.
Glechoma hederacea
Whole plant / above-ground
Ground ivy (Glechoma hederacea) is an old European cough and catarrh herb with no human trials; what the sources say about horse toxicity, pregnancy and kidney or liver cautions.
Ballota nigra
Whole plant / above-ground
Black horehound (Ballota nigra): what ESCOP and consumer references say about nervous tension and sleep, how little human research exists, and pregnancy and Parkinson's drug cautions.
Viola odorata
Whole plant / above-ground
Sweet violet (Viola odorata): a fragrant flower used as a cough syrup in folk medicine, with a few small trials, no EU monograph found, and cautions about roots and seeds.
Veronica officinalis
Whole plant / above-ground
Speedwell (Veronica officinalis): a traditional cough, skin and tonic tea with thin human evidence, a German negative monograph, and a real risk of getting a look-alike plant.
Galium odoratum
Whole plant / above-ground
Sweet woodruff (Galium odoratum): why its natural coumarin matters for headache and liver safety, Europe's coumarin limits for foods, and how little proper evidence exists for health uses.
Sanguisorba officinalis
Root
Great burnet root (Sanguisorba officinalis, di yu): used in Chinese medicine for bleeding and scalds, with thin human evidence and little published safety data.
Persicaria bistorta, Bistorta officinalis, Polygonum bistorta
Root
Bistort root (Persicaria bistorta): a very tannin-rich astringent used for diarrhoea and mouth problems, with no human trials found and no official safety assessment read.
Alcea rosea
Flower
Hollyhock flower (Alcea rosea): a mucilage and anthocyanin-rich garden plant used in traditional throat and cough teas, with no human trials found and little safety data.
Aegopodium podagraria
Whole plant / above-ground
Ground elder or goutweed (Aegopodium podagraria): a traditional gout and arthritis plant with no human trials, plus the real danger of confusing it with poisonous look-alikes.
Conium maculatum
Whole plant / above-ground
Poison hemlock (Conium maculatum) is a deadly plant, not a remedy. Why it is easily mistaken for wild carrot or parsley, what poisoning looks like, and who to call.
Colchicum autumnale
Seed
Autumn crocus (Colchicum autumnale) is a poisonous plant that contains colchicine, the gout drug. Why the margin is narrow, how it gets mistaken for wild garlic, and who to call.
Cinnamomum cassia
Stem
Cinnamon twig (gui zhi, Cinnamomi ramulus) from the cassia tree: how it differs from the bark, what we could and could not verify about coumarin, and liver and pregnancy cautions.
Magnolia biondii, Magnolia denudata, Magnolia sprengeri
Flower
Magnolia flower bud (xin yi, Magnolia biondii): a Chinese medicine herb for stuffy nose and allergic rhinitis, with little direct human evidence and thin safety data.
Atractylodes lancea
Rhizome
Atractylodes lancea rhizome (cang zhu): its place in Chinese medicine for dampness, digestion and eyes, the very thin human evidence, and why it is not bai zhu.
Lycium chinense, Lycium barbarum (pharmacopoeia co-source)
Bark
Lycium root bark (di gu pi, Lycii Cortex): a Chinese medicine herb, not goji berries. What lab and animal studies show on blood sugar and pressure, and why human evidence is thin.
Platycladus orientalis
Seed
Chinese arborvitae seed (bai zi ren, Platycladus orientalis): a Chinese-medicine seed used for sleep and constipation. Research is mostly mouse studies; mould toxins are a quality concern.
Curculigo orchioides
Rhizome
Curculigo (Curculigo orchioides, black or kali musli, xian mao): a rhizome used as a tonic in Ayurveda and Chinese medicine, with animal research only and no human safety data found.
Pueraria mirifica, Pueraria candollei var. mirifica
Root
Pueraria mirifica (kwao krua) root: a strongly estrogen-like Thai herb. What small menopause studies show, plus hormone-sensitive condition, bleeding and product-quality cautions.
Lycopodium clavatum
Whole plant / above-ground
Clubmoss (Lycopodium clavatum): why the spore powder should not be inhaled, how it differs from Huperzia and huperzine A, and why proper evidence of benefit is thin.
No herb matches all of these filters. Try removing one. Some topics (for example most herbs) are not herbs and live elsewhere on the site.
A link between a herb and a topic means the body needs the herb for that job, or that low intake is linked to it. It does not mean extra supplements help if your intake is already adequate. See each page’s evidence label.
Herbs traditionally used for relaxation, mood and sleep.
Herbs used around colds, infections and immune health.
Herbs used for nausea, stomach upset, bowel and liver complaints.
Herbs studied for blood pressure, cholesterol and blood sugar.
Herbs used for joint pain, inflammation and headaches.
Herbs used for menopause, urinary and prostate symptoms.
Herbs traditionally used to support stress resilience and stamina.
Herbs used on the skin for minor wounds, burns, bruises and irritation.
Culinary and other herbs that do not fit the groups above.
Herbs work alongside other nutrients. Here is what our sources link to them.
Vitamin A: The body can convert beta-carotene to vitamin A.
Vitamin A: Vitamin E and beta-carotene were tested together in the Finnish smoker trial.
Vitamin D: Vitamin D increases calcium absorption; both matter for bones, and treatment of rickets and osteomalacia includes both.
Vitamin D: NHS says vitamin D helps regulate calcium and phosphate.
Vitamin E: MedlinePlus says vitamin E helps the body use vitamin K; both affect blood clotting, which matters for people on blood thinners.
Vitamin E: Vitamin E and selenium were tested together and apart in the SELECT prostate cancer trial.
Vitamin E: Vitamin C and vitamin E were pooled with other antioxidants in the Cochrane mortality review.
Vitamin K: Vitamin D with K2 products exist; the site page does not claim an added benefit.
Vitamin B1 (thiamin): The NHS page covers B vitamins together; MedlinePlus says doctors may recommend other vitamins alongside thiamin for beriberi.
Vitamin B2: MedlinePlus says riboflavin works with the other B vitamins.
Vitamin B3 (niacin): Pellagra comes from too little niacin or tryptophan in the diet, so both matter for avoiding deficiency.
Vitamin B5: MedlinePlus covers pantothenic acid and biotin together; both are needed for growth and metabolism and for making fatty acids.
SupplementsOmega fatty acidsAntioxidantsSupplement formulasCompare supplementsNatural Remedy Safety
What herbs and botanicals are as health products, how traditional use differs from research, why scientific names matter, and where to start in this library.
An A to Z directory of the herb and botanical guides on AlternativeMed, with scientific names, the collection each guide belongs to, and cautions sources state.
How herbal products and conventional medicines differ in testing, regulation and labeling, what they share, and why telling your pharmacist about both matters.
How to read traditional use of herbs and modern research side by side, with real examples and the plain evidence labels used across this library.
How the terms herb, spice, tea, dietary supplement, natural health product and drug are defined, and why the same plant can fall into different categories.
Why the scientific name of an herb matters, how plant names work and change, and which common names cause mix-ups, with checked examples such as ginseng, chamomile and s…
Which part of a plant is in an herbal product, such as root, leaf, bark, flower or seed, and why the part named on a label changes what a study or a warning means.
Plain definitions of alkaloids, flavonoids, terpenes, glycosides and tannins in plants, with the point that a compound class is not a health claim and some compounds are…
What the title herbalist does and does not mean in the United States and the UK, how credentials and licenses differ, and what to ask before seeing a herbal practitioner.
Why picking wild or home-grown plants for health use carries poisoning and conservation risks, what the official sources advise, and where to get help.
How the United States, European Union, United Kingdom and Canada regulate herbal products, what claims are allowed on labels, and which herbal ingredients have been bann…
A short, respectful history of herbal medicine, from early written plant records in Egypt, China and Greece to monastery gardens and the isolation of plant compounds in …
Elderberry (Sambucus nigra): why raw berries, leaves and stems are poisonous, what reviews found for colds and flu, what is unknown, and how elderflower differs.
Echinacea (Echinacea purpurea and related species): what Cochrane, NCCIH and the EU herbal committee found for colds, and the allergy, medicine and pregnancy cautions.
Andrographis (Andrographis paniculata): what systematic reviews found for cough and sore throat, reports of allergic reactions, and what the sources we read do not say.
Goldenseal (Hydrastis canadensis): no rigorous human studies for colds, why pregnancy, breastfeeding and newborns are flagged, medicine interactions, and wild-harvest co…
Cat's claw (Uncaria tomentosa), also called una de gato: Amazonian traditional use, why human evidence is inconclusive, and cautions for autoimmune disease, bleeding and…
Pelargonium (Umckaloabo, Pelargonium sidoides): Southern African traditional use, Cochrane and EU findings on colds and bronchitis, and the disputed liver reports.
Mullein (Verbascum thapsus): what traditional use and EU herbal assessments say, why human evidence for coughs is thin, and the safety points for pregnancy, children and…
Marshmallow root (Althaea officinalis): the EU traditional-use assessment for throat irritation and dry cough, the limited trials, and the advice to space it from other …
Slippery elm (Ulmus rubra) inner bark: traditional use for sore throat and gut upset, what little human evidence exists, safety notes, and why the tree is a conservation…
Licorice root (Glycyrrhiza glabra): what research and EU and NIH sources say, why glycyrrhizin can raise blood pressure and lower potassium, medicine interactions, and h…
Ivy leaf (Hedera helix) extract for chesty cough: the EU well-established use, systematic reviews that call the benefit minimal, and allergy, age and stomach cautions.
Elecampane (Inula helenium) root: traditional use for chest and skin complaints, why human evidence is not found, and the daisy-family allergy point to know.
Eucalyptus leaf and leaf oil (Eucalyptus globulus): why swallowing the oil is dangerous, what EU regulators and trials say about cough and colds, and cautions for childr…
Lobelia (Lobelia inflata, "Indian tobacco"): why it carries a poisoning risk from lobeline, what the Cochrane review found on quitting smoking, and what is not proven.
Pau d'arco inner bark (Handroanthus impetiginosus): what the few human studies and many lab studies show, plus bleeding, blood-thinner, pregnancy and quality cautions.
Forsythia fruit (Forsythia suspensa, lian qiao): what human trials, lab studies and traditional use show for colds and inflammation, plus pregnancy, bleeding and surgery…
Honeysuckle flower (Lonicera japonica, jin yin hua): what the research shows on COVID-19 add-on use and skin rash, why the berries are not safe, and why species and form…
Hyssop leaf (Hyssopus officinalis): what research shows, why the essential oil is linked to seizures, and cautions for pregnancy, children and epilepsy.
White horehound (Marrubium vulgare): what the EU says about traditional use for cough and indigestion, how little human research exists, and pregnancy, diabetes and kidn…
Baikal skullcap (Scutellaria baicalensis, huang qin) root: liver injury reports, what small human trials and lab studies show, and why it is not American skullcap.
Platycodon (balloon flower, jie geng), the root of Platycodon grandiflorus: its use for cough and sore throat, the few small human trials, and the safety gaps to know.
Isatis (ban lan gen, woad root, Isatis tinctoria): what the sources say about colds and flu, the thin human evidence, and medicine, pregnancy and Qing Dai cautions.
Osha root (Ligusticum porteri), also called bear root: what is known about colds and coughs, why no human trials exist, the deadly hemlock look-alike, and wild-harvest c…
Boneset (Eupatorium perfoliatum): a fever and cold herb of North American tradition. Lab tests found liver-toxic pyrrolizidine alkaloids in it, and human trials are miss…
Coltsfoot leaf (Tussilago farfara) has been used for coughs, but it can contain liver-toxic pyrrolizidine alkaloids. What EU, EFSA and research sources say, and why the …
Sweet wormwood (Artemisia annua), the plant behind artemisinin: why WHO does not support the plant or its tea for malaria, plus liver, resistance, pregnancy and look-ali…
Cinchona bark (Cinchona officinalis and relatives), the source of quinine: why it is a risky herb, what quinine warnings say, and what research shows about malaria and l…
Houttuynia (Houttuynia cordata, fish mint, yu xing cao): a leafy herb eaten in parts of Asia, with serious allergic reactions reported to its injection and little human …
Saposhnikovia root (fang feng, Saposhnikovia divaricata): a Chinese-medicine root known from Yu Ping Feng San, with sun-sensitivity chemistry, look-alike roots and thin …
Vasaka leaf (Justicia adhatoda, also called Adhatoda vasica): traditional cough remedy and source plant of bromhexine, with pregnancy and uterine-stimulant cautions and …
Yerba santa leaf (Eriodictyon californicum): a California plant used traditionally for coughs and colds and as a flavoring, with almost no human research and unclear saf…
Self-heal (Prunella vulgaris, xia ku cao): traditional use for thyroid swelling and cold sores, what trials and lab studies show, and the cautions that apply.
Wild cherry bark (Prunus serotina) in cough syrups: why the plant contains cyanide-releasing compounds, how thin the human evidence is, and cautions for pregnancy, child…
Pleurisy root (Asclepias tuberosa, butterfly weed): a traditional chest herb with no human trials, cardiac glycoside and heart-medicine cautions, pregnancy warnings and …
Usnea (old man's beard lichen, Usnea barbata) contains usnic acid, linked to serious liver injury and liver failure in weight-loss products; what the sources say and why…
Common mallow (Malva sylvestris): what the EU herbal committee says about flower and leaf teas for throat irritation, the single small constipation trial, and cautions f…
Lungwort (Pulmonaria officinalis) is an old cough herb named for its lung-shaped leaves. See what the sources say, why human evidence is missing, and the open liver-alka…
Kantakari, the yellow-berried nightshade (Solanum virginianum): its Ayurvedic cough and asthma use, the one small human trial found, and why a nightshade with glycoalkal…
Angelica dahurica (bai zhi) root: traditional use for headache and stuffy nose, what research does and does not show, and sun-sensitivity, pregnancy and medicine caution…
Xanthium fruit (cang er zi, cocklebur, Xanthium sibiricum) is used in Chinese medicine for nasal complaints, but it contains liver-toxic compounds and has been linked to…
Pinellia (ban xia, Pinellia ternata): a Chinese-medicine tuber used for nausea and phlegm, toxic when raw, with processing, pregnancy and quality cautions and little hum…
Thuja (northern white cedar, Thuja occidentalis): thujone toxicity, why it is avoided in pregnancy, what is known about warts and coughs, and Echinacea-thuja products.
Sutherlandia (cancer bush, Lessertia frutescens): what small human trials and lab studies show, and why antiretroviral and tuberculosis-prevention medicine interactions …
Papaya leaf (Carica papaya): small dengue trials report higher platelet counts, but reviews say proof is weak; pregnancy, liver, diabetes-medicine and latex-allergy caut…
European mistletoe (Viscum album): why the leaves, berries and teas can poison, what research says about injected extracts such as Iscador in cancer care, and who needs …
Perilla (shiso, su ye) leaf, Perilla frutescens: what small trials and reviews show for hay fever and digestion, plus perilla ketone, allergy and pregnancy cautions.
Sophora flavescens (ku shen) root contains matrine and oxymatrine; what research says on hepatitis B and skin uses, plus liver and nerve-toxicity cautions.
Fritillaria bulb (chuan bei mu, Fritillaria cirrhosa and relatives): its traditional use for cough, why human trial evidence is missing, and aconite, adulteration and wi…
Cryptolepis (Cryptolepis sanguinolenta), a West African root tea used for malaria: small open studies, lab signs of DNA and cell toxicity, and why it is not a safe repla…
African wormwood (Artemisia afra): a southern African herbal tea plant with no proven use against malaria or COVID-19, what WHO and lab studies say, and the safety quest…
Yerba mansa root (Anemopsis californica): a wetland plant of the American Southwest used in folk medicine, with only lab research behind it, plus habitat-conservation an…
White sage (Salvia apiana), a California native: its sacred place for many Native peoples, poaching and habitat loss, smoke and air quality, and what lab studies do and …
Wild indigo root (Baptisia tinctoria): its cytisine-type alkaloids, vomiting at large amounts, pregnancy cautions, and what trials of Echinacea-Baptisia-Thuja cold produ…
Red root (Ceanothus americanus, New Jersey tea): traditional uses for bleeding, lymph and spleen, what little research exists, and why a possible clotting effect needs c…
Garden nasturtium (Tropaeolum majus): a mustard-oil herb tested only in a fixed horseradish combination for bronchitis and cystitis, with stomach, kidney and pregnancy c…
Watercress (Nasturtium officinale) as an herb: what small trials of watercress and its compound PEITC found, plus warfarin, liver-fluke, drug-processing and quality caut…
Iceland moss (Cetraria islandica) is a lichen, not a moss, used as a soothing tea or lozenge for dry cough and sore mouth and throat; what EU regulators say, and the lea…
Cowslip (Primula veris) flower and root: why EU regulators allow it only as a traditional cough remedy, what thyme-primula trials show, and pregnancy, stomach and allerg…
Sundew (Drosera rotundifolia), a carnivorous bog plant traditionally used for cough and whooping cough: what little research exists, safety cautions, and why wild pickin…
Bee balm or Oswego tea (Monarda didyma, also Monarda fistulosa): thin evidence, one small human trial, no agency review, and pregnancy and safety-data gaps explained.
Common sorrel (Rumex acetosa): oxalic acid cautions for kidney stones and kidney disease, what trials of the five-herb Sinupret mix show for sinus infection, and why the…
Ground ivy (Glechoma hederacea) is an old European cough and catarrh herb with no human trials; what the sources say about horse toxicity, pregnancy and kidney or liver …
Sweet violet (Viola odorata): a fragrant flower used as a cough syrup in folk medicine, with a few small trials, no EU monograph found, and cautions about roots and seed…
Speedwell (Veronica officinalis): a traditional cough, skin and tonic tea with thin human evidence, a German negative monograph, and a real risk of getting a look-alike …
Hollyhock flower (Alcea rosea): a mucilage and anthocyanin-rich garden plant used in traditional throat and cough teas, with no human trials found and little safety data.
Magnolia flower bud (xin yi, Magnolia biondii): a Chinese medicine herb for stuffy nose and allergic rhinitis, with little direct human evidence and thin safety data.
Chamomile (Matricaria chamomilla): what NIH and EU regulators say, what trials found for anxiety and sleep, allergy risks with daisy-family plants, and medicine interact…
Valerian (Valeriana officinalis): what NIH, a sleep medicine guideline and EU regulators say about sleep, plus alcohol and sedative cautions, withdrawal effects and rare…
St. John's wort (Hypericum perforatum): trial evidence for mild to moderate depression, and well-documented interactions with antidepressants, birth control, transplant …
Passionflower (Passiflora incarnata): what NIH, EU regulators and trials say about anxiety and sleep, and the cautions for pregnancy, surgery and sedating medicines.
Lemon balm (Melissa officinalis): what an EU regulator, systematic reviews and liver-safety records say about stress, anxiety and sleep, and what safety questions remain…
Lavender (Lavandula angustifolia) as a herb: what trials of an oral standardized lavender oil preparation found for anxiety, what the EU says, and safety cautions.
Skullcap (Scutellaria lateriflora): small studies on mood and sleep, documented liver injury cases and germander adulteration, and why Chinese skullcap is a different pl…
Hops (Humulus lupulus) beyond beer: what European regulators and trials say about sleep, stress and menopause, the estrogen-like compound, and who should ask first.
California poppy (Eschscholzia californica) is used for nervousness and sleep. What the few human trials and lab studies show, and what the sources do not say about safe…
Catnip (Nepeta cataria) is a mint-family herb used as a tea for people. We looked for human trials on calm and sleep and report what we found and did not find.
Linden flower (Tilia cordata and Tilia platyphyllos), also called lime flower: the European traditional-use statement, the missing human trials, and cautions for infants…
Motherwort (Leonurus cardiaca) for nervous tension and heart-related nervousness: the European traditional-use statement, one small trial, and the pregnancy contraindica…
Lemon verbena (Aloysia citrodora) as a tea and extract: small trials on stress, sleep, muscle recovery and blood pressure, their company links, and what is not known abo…
Saffron (Crocus sativus) as a spice and as a supplement: what meta-analyses say about mood and anxiety, how common side effects are, bleeding and mania cautions, and fak…
Kava root (Piper methysticum): rare but serious liver injury, bans in several countries, mixed trial results for anxiety, and sedative, alcohol and pregnancy cautions.
Blue lotus flower (Nymphaea caerulea): no good human trials, psychoactive alkaloids that vary by product, reports of confusion after vaping, and unclear legal status.
Blue vervain (Verbena hastata): a North American plant used in folk medicine for nerves and sleep, with no human trials found and little modern safety testing.
Wild lettuce (Lactuca virosa), sometimes sold as "lettuce opium": what the sources say about sleep and pain claims, the poisoning case reports, and why human evidence is…
Kanna (Sceletium tortuosum) is a psychoactive southern African plant sold for mood and stress. Small trials, an antidepressant (SSRI) interaction concern, and legal and …
Jatamansi (Nardostachys jatamansi), an Ayurvedic root also called spikenard: little human research, a critically endangered wild plant, and why safety data are thin.
Wood betony (Stachys officinalis): a traditional European herb for nerves and headaches. We found no human trials, so here is what is known and not known about safety.
Jujube fruit (Ziziphus jujuba, da zao) and the sleep seed suan zao ren: what small trials and reviews found, and the sedative, blood-sugar, surgery and pregnancy caution…
Magnolia bark (Magnolia officinalis, hou po): honokiol and magnolol, what small trials of blends found for stress and sleep, and sedative, pregnancy and kidney-case caut…
Griffonia seed (Griffonia simplicifolia) is the commercial source of 5-HTP. What research shows for low mood, and why antidepressant, surgery and contamination cautions …
Albizia (mimosa tree bark, he huan pi): a Chinese calming herb with no human trials in the sources we read, plus sedative, pregnancy and surgery cautions.
Tagara (Indian valerian, Valeriana wallichii): an Ayurvedic calming root. What small trials and reviews show, why sedation and sourcing matter, and what is known about i…
Lotus seed (lian zi, Nelumbo nucifera) and its green core: traditional use for sleep and loose stools, one small unblinded sleep pilot, mostly lab research, and constipa…
Lion's tail or wild dagga (Leonotis leonurus), a South African plant smoked or brewed as tea: traditional use, no human trials found, rat toxicity findings, and look-ali…
Oat straw and milky oats (Avena sativa): what the EU says about traditional use for stress and sleep, small trials of green oat extract on thinking, and gluten questions…
Lily bulb (bai he, Lilium brownii and related species): a food-and-medicine bulb in Chinese tradition, what trials and reviews show for sleep and mood, and the cat-toxic…
European vervain (Verbena officinalis): the thin human evidence, its role in the five-herb Sinupret sinus product, and the pregnancy, children and alcohol-drops cautions.
Sweet woodruff (Galium odoratum): why its natural coumarin matters for headache and liver safety, Europe's coumarin limits for foods, and how little proper evidence exis…
Chinese arborvitae seed (bai zi ren, Platycladus orientalis): a Chinese-medicine seed used for sleep and constipation. Research is mostly mouse studies; mould toxins are…
Ginger rhizome (Zingiber officinale): what research and EU regulators say about nausea and digestion, plus blood-thinner, surgery, pregnancy and side-effect cautions.
Peppermint (Mentha x piperita): what research shows for IBS and indigestion, how leaf and oil differ, and heartburn, gallstone, liver and child cautions from EU and NIH …
Fennel fruit or seed (Foeniculum vulgare): EU regulator limits, estragole limits for children and pregnancy, and what trials found for infant colic and digestion.
Caraway fruit (Carum carvi): traditional use for bloating, what trials found for peppermint-and-caraway oil combinations, and EU cautions on liver, gallbladder and aller…
Anise or aniseed (Pimpinella anisum): traditional digestive use, thin trial evidence, EU cautions for allergy, pregnancy and children, and how it differs from toxic-risk…
Cardamom seed (Elettaria cardamomum): mostly a food spice; what meta-analyses of small trials found for blood fats and inflammation markers, and gallstone and pregnancy …
Artichoke leaf (Cynara cardunculus): what Cochrane and meta-analyses found for indigestion and cholesterol, and EU contraindications for bile-duct, gallstone and liver d…
Dandelion (Taraxacum officinale): what the EU herbal committee and human studies say about digestion and urine output, and the allergy, gallstone, ulcer and potassium ca…
Aloe vera gel, latex and whole-leaf extract are different products: what NCCIH and FDA say about burns, laxative use, liver reports, animal cancer findings and pregnancy.
Senna (Senna alexandrina) is a stimulant laxative for short-term constipation: what EU, UK and US guideline sources say, plus limits on use, potassium, pregnancy and lax…
Gentian root (Gentiana lutea) is a bitter herb used traditionally for appetite and mild indigestion: what the EU herbal committee concluded, the limited evidence and the…
Chicory root (Cichorium intybus) and its inulin fiber: what trials and meta-analyses found for constipation, how gas and bloating can limit use, and reported allergy to …
Spearmint (Mentha spicata): what two small tea trials found for hormone levels in women with excess hair growth, what is unknown, and how it differs from peppermint.
Cascara sagrada (Frangula purshiana, also named Rhamnus purshiana) is a bark used as a stimulant laxative: what the EU committee and US FDA say, and limits on use, potas…
Psyllium seed husk (Plantago ovata): what trials and EU regulators say about constipation, IBS and cholesterol, plus choking, allergy, medicine-timing and pregnancy caut…
Wormwood (Artemisia absinthium), the bitter herb behind absinthe: what EU regulators and small trials say, plus thujone, seizure, liver, pregnancy and sweet wormwood cau…
European angelica root (Angelica archangelica): what the sources say about digestive use, the sun-sensitivity risk from furanocoumarins, and why it is not the same as do…
Triphala is an Ayurvedic blend of three fruits (haritaki, bibhitaki, amla); what trials found on mouthwash, cholesterol and bowels, plus medicine, pregnancy and metal-qu…
Blessed thistle (Cnicus benedictus): what EU regulators say about its traditional use for poor appetite and indigestion, why no trials exist, and daisy-family allergy an…
Agrimony (Agrimonia eupatoria) above-ground parts: EU traditional use for mild diarrhoea, mouth and skin, with no human trials found and pregnancy and children cautions.
Yellow dock root (Rumex crispus): a traditional laxative and "blood cleanser" with no human trials found, plus oxalate and kidney stone cautions and a thrombocytopenia c…
Coptis (goldthread, huang lian), a berberine-rich root: what trials found for blood sugar, and why newborn jaundice, pregnancy and many medicines call for caution.
Atractylodes macrocephala rhizome (bai zhu): how it is used in Chinese formulas for digestion, what the few human studies show, and cautions on pregnancy and daisy-famil…
Bael fruit (Aegle marmelos): traditional Ayurvedic digestive and blood-sugar use, what little human research exists, and cautions with diabetes medicines and supplements.
Rhubarb root (Rheum palmatum, da huang) is a stimulant laxative: what EU and US sources say, why the leaves of garden rhubarb are poisonous, and kidney and pregnancy cau…
Job's tears or coix seed (Coix lacryma-jobi, yi yi ren): what trials and reviews found, why kanglaite injection is a different product, and pregnancy, blood sugar and mo…
Chinese yam (shan yao, Dioscorea polystachya): a food and traditional East Asian tonic. What the sources say about digestion and blood sugar (mostly animal work), and wh…
Centaury (Centaurium erythraea), a bitter flowering herb: the EU accepts it only as a traditional medicine for mild indigestion and loss of appetite, with no trials, and…
Haritaki (Terminalia chebula fruit), one of the three fruits of triphala: what the few small human trials found, plus medicine, diabetes, pregnancy and product-quality c…
Bibhitaki (Terminalia bellirica, bahera) is one of the three fruits of triphala; what the sources say about evidence, blood sugar, pregnancy, surgery and product quality.
Chitrak (Plumbago zeylanica), an Ayurvedic root: what the sources say about its toxic plumbagin, skin irritation, pregnancy, liver and kidney cautions, and the lack of h…
Kutaja or kurchi bark (Holarrhena antidysenterica, accepted name H. pubescens): Ayurvedic use for dysentery and diarrhoea, thin human evidence, animal toxicity signals a…
Tangerine peel (chen pi, Citrus reticulata): what we found on digestion and flavonoid research, mold in aged peel, and why strong claims are not yet backed by good human…
Alpinia oxyphylla fruit (yi zhi ren, bitter cardamom): used in Chinese medicine for urinary frequency and diarrhoea, with lab studies on the brain but no human trials fo…
Guava leaf (Psidium guajava) as tea or extract: what small trials and reviews say about diarrhoea and blood sugar, and what is still unknown about safety and medicine in…
Greater celandine (Chelidonium majus): why EU regulators call oral use a negative benefit-risk, the liver injury reports, the wart latex tradition, and a not-lesser-cela…
Epazote (Dysphania ambrosioides): the Mexican cooking herb versus wormseed oil and strong infusions, which have caused child deaths. Evidence, pregnancy and safety cauti…
Evodia fruit (wu zhu yu, Tetradium ruticarpum): its traditional use for headache and cold stomach pain, what human evidence exists, and the liver, heart and medicine-int…
Korean mint (Agastache rugosa, called huo xiang) explained: how it differs from patchouli, what trials of the huo xiang zheng qi formula found, and its estragole and qua…
Amomum fruit (sha ren, Amomum villosum, now Wurfbainia villosa): a Chinese digestive herb; what animal studies show, why pregnancy use rests on tradition only, and cauti…
Cranesbill or wild geranium root (Geranium maculatum): an old tannin-rich astringent for diarrhoea and mouth problems with no good human evidence, and unknown safety.
Fumitory (Fumaria officinalis): what the EU regulator says about digestive complaints and bile, the one negative IBS trial, and cautions for liver and gallbladder proble…
Costus root (mu xiang, Saussurea costus): an endangered Himalayan root, a skin allergen, and a name confused with a kidney-toxic plant. What the sources say, and how lit…
Chirata (Swertia chirayita), an intensely bitter Himalayan herb: what is known about its traditional use, why human evidence is thin, and blood-sugar, supply and quality…
Tormentil rhizome (Potentilla erecta): an EU traditional herbal medicine for mild diarrhoea and mouth inflammation, based on long use and lab work, with no good human tr…
Silverweed (Potentilla anserina, now Argentina anserina): a tannin-rich traditional herb for cramps and diarrhea, with thin human evidence and pregnancy and medicine-tim…
Black horehound (Ballota nigra): what ESCOP and consumer references say about nervous tension and sleep, how little human research exists, and pregnancy and Parkinson's …
Bistort root (Persicaria bistorta): a very tannin-rich astringent used for diarrhoea and mouth problems, with no human trials found and no official safety assessment rea…
Atractylodes lancea rhizome (cang zhu): its place in Chinese medicine for dampness, digestion and eyes, the very thin human evidence, and why it is not bai zhu.
Garlic (Allium sativum): bleeding risk and surgery, burns from raw garlic on skin, what reviews found for cholesterol, blood pressure and blood sugar, and safety in preg…
Hawthorn (Crataegus): what a Cochrane review and EMA say about heart failure and "nervous" heart complaints, digoxin and blood pressure medicine cautions, and a toxic lo…
Cinnamon (Ceylon Cinnamomum verum and cassia): coumarin and liver caution, mixed blood sugar evidence, species confusion on labels, and food amounts versus supplements.
Fenugreek (Trigonella foenum-graecum): pregnancy warning, legume allergy, blood sugar medicine cautions, mixed evidence for diabetes and milk supply, and the maple-syrup…
Bitter melon (Momordica charantia): a Cochrane review found insufficient evidence for blood sugar, newer reviews are more positive, and pregnancy and medicine safety dat…
Gymnema sylvestre leaf: its traditional use for sugar, what trials and reviews found for blood glucose and sweet cravings, and the low blood sugar caution with diabetes …
Barberry (Berberis vulgaris): what meta-analyses found for blood sugar, cholesterol and blood pressure, the berberine link, and cautions for medicines, pregnancy and new…
Oregon grape (Mahonia aquifolium): what reviews and trials found for psoriasis creams, its berberine content, and cautions for medicines, pregnancy and newborns.
Coleus forskohlii and forskolin: which plant name is used, what small trials found for body fat and weight loss claims, and cautions for blood pressure and blood-thinnin…
Hibiscus (roselle) calyces: what trials and reviews found for blood pressure and cholesterol, why medicine users and pregnant readers should ask first, and what is not k…
Olive leaf (Olea europaea): what EU regulators and trials say about blood pressure, blood sugar and water retention, who should ask first, and what is not known.
Guggul (Commiphora wightii): Ayurvedic tradition, why Western cholesterol trials found no benefit, rash and medicine-interaction reports, and why the wild tree is endang…
Stevia (Stevia rebaudiana): what the FDA and EFSA say about purified sweeteners versus whole leaf, what trials found for blood pressure and blood sugar, and who should a…
Horse chestnut (Aesculus hippocastanum): why raw seeds, bark and leaves are toxic, what standardized seed extract showed for leg vein problems, and the EU and NIH cautio…
Butcher's broom (Ruscus aculeatus): EU traditional-use status for heavy legs and hemorrhoid itching, what trials found, why combination-product results do not transfer, …
Berberine from Berberis, Coptis and goldenseal plants: what trials found for blood sugar and cholesterol, why newborns and many medicines are a concern, and what is unpr…
Arjuna bark (Terminalia arjuna): what small heart-health trials found, what is unclear, and cautions on heart medicines, pregnancy, allergy and heavy-metal contamination.
Bitter orange (Citrus aurantium) peel and synephrine supplements: heart rhythm and blood pressure warnings, what weight-loss trials found, label problems, and who should…
Flaxseed (Linum usitatissimum): what regulators and trials say about constipation, cholesterol and hot flashes, plus choking, hormone, pregnancy and medicine cautions.
Danshen (red sage root, Salvia miltiorrhiza): warfarin and blood-thinner bleeding warnings first, then what trials of danshen pills found for angina and what is unproven.
White mulberry leaf (Morus alba): what research says about blood sugar after meals, why it can add to diabetes medicines, and what is unknown for pregnancy and surgery.
Eucommia bark (Eucommia ulmoides, du zhong): what small blood pressure and bone trials show, what is only lab or animal work, and why safety data in people are thin.
Prickly pear (nopal), Opuntia ficus-indica: what small human studies found for blood sugar, cholesterol and bowel symptoms, plus diabetes-medicine, skin and home-canning…
Hoodia (Hoodia gordonii) is sold for appetite and weight loss, but the one small human trial found no effect, some worrying changes in blood pressure and tests, and copi…
Garcinia cambogia fruit rind (Garcinia gummi-gutta): what weight-loss trials found, and why liver-injury reports, a USP caution and NCCIH safety warnings matter before u…
Green (unroasted) coffee bean extract: the retracted weight-loss study behind the hype, what later trials found, and caffeine, medicine, pregnancy and heart cautions.
White kidney bean extract (Phaseolus vulgaris), sold as a "starch blocker": what trials show about small weight changes, and why raw or undercooked kidney beans are pois…
Irvingia (African mango seed, Irvingia gabonensis): what weight-loss and cholesterol trials show, why their quality is questioned, and blood sugar, kidney and pregnancy …
Bergamot fruit (Citrus bergamia): what trials of bergamot extract found for cholesterol, why the oil makes skin sun-sensitive, and the medicine, pregnancy and Earl Grey …
Foxglove (Digitalis purpurea) is a poisonous garden plant, not a herbal remedy. Why every part can harm the heart, how it gets mistaken for comfrey, and who to call.
Safflower flower (Carthamus tinctorius, hong hua): what is known about its use in Chinese medicine, the thin human evidence, and bleeding, pregnancy and allergy cautions.
Uncaria (gou teng, Uncaria rhynchophylla): a Chinese medicine hooked stem tied to blood pressure formulas. What trials show, why it is not cat's claw, and medicine cauti…
Goat's rue (Galega officinalis): the plant that led to metformin, why it can lower blood sugar and poison livestock, and what is known about its use for milk supply.
Sarpagandha (Indian snakeroot, Rauvolfia serpentina) is the plant source of reserpine: what sources say about blood pressure, depression, cancer worries, pregnancy and a…
Grape seed extract (Vitis vinifera): what reviews found for blood pressure and cholesterol, what is only lab work, and the blood-thinner, medicine and pregnancy cautions.
Stone root (Collinsonia canadensis): old uses for hemorrhoids, varicose veins and kidney stones, why no human trials were found, and the thin safety information.
Yacon (Smallanthus sonchifolius): what trials of the root syrup and flour show for blood sugar, weight and bowels, what is unproven for the leaf tea, and cautions.
Japanese knotweed root (Reynoutria japonica, hu zhang): the main commercial source of resveratrol, also rich in laxative emodin compounds; what the research shows, cauti…
Bitter leaf (Vernonia amygdalina): a West African food and folk remedy. What small human studies and animal work show for malaria and blood sugar, and a serious Ugandan …
Northern prickly ash bark (Zanthoxylum americanum), the "toothache tree": traditional uses, what lab studies and the few reviews found, and stomach, pregnancy and medici…
Sweet clover or melilot (Melilotus officinalis): EU traditional use for heavy legs, thin evidence, and the coumarin issues behind liver and blood-thinner cautions, plus …
Oleander (Nerium oleander) is a poisonous garden shrub, not a herbal remedy. Heart danger from every part, leaf-tea mix-ups, burning smoke, supplement look-alikes, and w…
Lily of the valley (Convallaria majalis) is a poisonous garden plant with heart-active compounds, not a safe herbal remedy. Symptoms, wild garlic mix-ups and who to call.
Salacia reticulata root and stem: small trials on after-meal blood sugar and HbA1c, the low blood sugar caution with diabetes medicines, stomach effects, and pregnancy w…
Vijaysar (Indian kino, Pterocarpus marsupium) heartwood: its Ayurvedic use for diabetes, the small human studies behind it, and the low blood sugar caution with diabetes…
Jamun (Java plum) seed, Syzygium cumini: traditional use for diabetes, what small trials found, and why people on diabetes medicines or pregnant should check first.
Scotch broom (Cytisus scoparius): why this alkaloid-containing shrub is listed as likely unsafe by mouth, with pregnancy, heart, blood pressure and MAOI antidepressant c…
Cinnamon twig (gui zhi, Cinnamomi ramulus) from the cassia tree: how it differs from the bark, what we could and could not verify about coumarin, and liver and pregnancy…
Ginkgo (Ginkgo biloba): toxic seeds, bleeding questions with blood thinners, what NIH and European regulators say, and what large trials found for dementia and tinnitus.
Bacopa (Bacopa monnieri, also called brahmi): its use in Ayurveda, what reviews of trials found for memory and attention, common stomach side effects, and gaps in safety…
Gotu kola (Centella asiatica): reports of liver injury, the EU skin-use monograph for minor wounds, small studies on memory and anxiety, and why "brahmi" can mean two pl…
Rosemary (Salvia rosmarinus, also Rosmarinus officinalis): the EU leaf monograph and its cautions, two small oral trials on memory, and what is not known about supplemen…
Common sage (Salvia officinalis): thujone and seizure risk at high amounts, small studies on hot flashes and memory, EU monograph limits, and pregnancy cautions.
Lesser periwinkle (Vinca minor) and vinpocetine, the lab-made compound sold as a memory supplement: what FDA, Cochrane and other sources say about evidence and pregnancy.
Huperzia serrata and huperzine A, a supplement that works like Alzheimer's medicines: what trials and reviews found, and the medicine and heart-rate cautions.
Butterbur (Petasites hybridus) was studied for migraine, but pyrrolizidine alkaloids and rare liver injury led guidelines to stop recommending it. What the sources say.
Feverfew (Tanacetum parthenium) is used to try to prevent migraine: what Cochrane and EU reviews found, post-feverfew symptoms, pregnancy, bleeding and daisy-family alle…
Guarana seed (Paullinia cupana): a caffeine-rich herb. What research shows on focus and fatigue, and cautions for the heart, blood pressure, pregnancy, children and surg…
Mucuna pruriens (velvet bean) seed is a natural source of levodopa. What Parkinson's trials show, and the medicine, psychiatric, seed-hair and fertility-claim cautions.
Kola nut seed (Cola nitida): a caffeine-containing West African chewing seed. What the EU assessment found, why trials are missing, and cautions for pregnancy, children,…
Polygala root (yuan zhi, Polygala tenuifolia): what reviews say about memory and sleep claims, saponin stomach and throat irritation, pregnancy cautions and look-alike s…
Gastrodia (tian ma, Gastrodia elata) is an orchid tuber used in Chinese medicine for headache and dizziness; the human trials we found tested the isolated compound gastr…
Shankhpushpi (Convolvulus prostratus, also called C. pluricaulis) in Ayurveda: one small human trial, mostly lab and animal findings, and why products may hold other pla…
Malkangani or intellect tree (Celastrus paniculatus, jyotishmati): memory claims rest on animal studies, no human trial results found, and human safety data are missing.
Saw palmetto (Serenoa repens) berry extract: what NIH, the Cochrane Library and EU regulators say about prostate symptoms and hair loss, plus the safety points to know.
Black cohosh (Actaea racemosa) root extract for menopause symptoms: what NIH and EU regulators found, the rare liver injury reports, adulteration and who should be caref…
Red clover (Trifolium pratense) isoflavone extracts for menopause symptoms: what NIH and a meta-analysis found, plus cautions on blood thinners, hormone-sensitive cancer…
Chasteberry (Vitex agnus-castus) fruit extract for PMS and breast pain: what NIH, EU regulators and a meta-analysis found, with cautions on hormone medicines and pregnan…
Dong quai (Angelica sinensis) root as a single herb: one placebo-controlled trial, an EU regulator statement, and cautions on warfarin, sun sensitivity, hormones and pre…
Evening primrose oil (Oenothera biennis seed oil): what NIH and EU regulators say about PMS, breast pain and skin, plus blood thinner, blood pressure and pregnancy cauti…
Red raspberry leaf (Rubus idaeus) is widely used in pregnancy. What the labor trials and reviews found, what is not known about safety, and why to tell your midwife.
Wild yam (Dioscorea villosa) is sold as a "natural progesterone" cream or supplement. What the sources say about hormones, menopause trials and safety, and what they do …
Stinging nettle (Urtica dioica) leaf and root: what research and EU and NIH sources say about prostate symptoms, allergies and blood sugar, and the cautions for medicine…
Pygeum (Prunus africana) bark extract is used for prostate urinary symptoms. What a Cochrane review and EU and NIH sources say, the conservation status of the tree, and …
Tribulus (Tribulus terrestris) is marketed to raise testosterone. What systematic reviews found for testosterone and erectile function, a kidney and liver case report, a…
Horsetail (Equisetum arvense) is used for urine flow, wounds and hair or nail claims. What EU assessments and trials show, plus thiaminase, nicotine, look-alike species …
White peony root (Paeonia lactiflora, Bai shao): what European regulators and trial reviews found, why there is no EU monograph, and pregnancy and medicine cautions.
Damiana leaf (Turnera diffusa): traditional use as an aphrodisiac and tonic, the small human studies we could read, and cautions on medicines, pregnancy and blood sugar.
Black haw bark (Viburnum prunifolium): a traditional uterine herb with almost no modern human research, plus pregnancy, aspirin-allergy, kidney-stone and blood-thinner c…
Cramp bark (Viburnum opulus) is used traditionally for period and muscle cramps, but the sources we read found no human trials and too little safety data to judge it.
Blue cohosh root (Caulophyllum thalictroides): why it is linked to heart and stroke harms in newborns when used for labor, what research exists, and how it differs from …
Shatavari root (Asparagus racemosus): what small trials and reviews show for lactation, menopause and women's health, and what is not yet known about safety.
Horny goat weed (Epimedium, yin yang huo): what sources say about bone loss and sexual health claims, plus heart, hormone-sensitive cancer, liver and medicine cautions.
Muira puama (Ptychopetalum olacoides) bark and root: what the sources say about libido and nerve-tonic claims, how little human safety data exists, and what to ask befor…
Lady's mantle (Alchemilla vulgaris): a tannin-rich herb used for diarrhea and women's complaints; what the limited research shows and the cautions to know about.
Shepherd's purse (Capsella bursa-pastoris): what EU regulators and one small trial say about heavy periods, why heavy bleeding needs a doctor, and pregnancy cautions.
Kudzu root (ge gen, Pueraria montana var. lobata): small trials on alcohol drinking and menopause, plus estrogen-like activity, tamoxifen, methotrexate and liver or kidn…
Ashoka bark (Saraca asoca): an Ayurvedic tree bark used for menstrual problems, with very little human research, a threatened wild supply, and a known look-alike bark so…
Pennyroyal (Mentha pulegium and American pennyroyal): why swallowing the oil or herb has caused liver failure and deaths, including infants and abortion attempts, and wh…
Yohimbe bark (Pausinystalia johimbe): what research and health agencies say about sexual-health and weight-loss claims, plus heart, blood pressure, anxiety and label-acc…
Fadogia agrestis stem: popular online as a testosterone booster, yet the sources we read show only rat studies, signs of organ stress in those animals, and no human tria…
Catuaba bark (Trichilia catigua and look-alike plants sold under the same name): what the lab research shows, why products are often mixed up, and safety cautions.
Safed musli root (Chlorophytum borivilianum): Ayurvedic use for stamina and libido, the few small human trials, wild-stock decline, look-alike roots and what is not know…
Vidari kanda (Indian kudzu, Pueraria tuberosa) tuber: what Ayurveda uses it for, what little human research exists, and cautions on hormones, pregnancy and look-alikes.
Bugleweed (Lycopus virginicus, also L. europaeus) is promoted for an overactive thyroid. Read what little human research exists and why thyroid medicines and scans matte…
Nut grass rhizome (Cyperus rotundus; mustaka, xiang fu): traditional menstrual and digestive use, one small weight trial, what is unknown about safety, and a garden weed.
Lodhra bark (Symplocos racemosa): an Ayurvedic bark used for periods, PCOS and uterine complaints, with almost no human research, mixed-formula trials only, and look-ali…
Cuscuta seed (tu si zi, Chinese dodder seed, Cuscuta chinensis): traditional kidney and fertility use, what a 2025 review found, and why pregnancy and medicine cautions …
Morinda root (ba ji tian, Morinda officinalis): what research says about bone and mood use, why it is not noni, and what is unknown about liver, laxative and drug-intera…
Moutan, the root bark of tree peony (Paeonia suffruticosa, mu dan pi): what reviews say about its evidence, why it is not white peony, and pregnancy and heavy-period cau…
False unicorn root (Chamaelirium luteum): a threatened North American plant used traditionally for menstrual and fertility concerns, with almost no human research and re…
Partridgeberry (Mitchella repens) is a traditional late-pregnancy and labor herb. The only study we found was in mouse tissue; there are no human trials, and pregnancy s…
African potato corm (Hypoxis hemerocallidea): traditional immune tonic with no proven benefit for HIV or prostate; what reviews show, plus antiretroviral interaction and…
Dhataki (fire-flame bush, Woodfordia fruticosa) flowers: Ayurvedic use for menstrual and uterine problems, lab findings on tannins, and why human safety data are missing.
Curculigo (Curculigo orchioides, black or kali musli, xian mao): a rhizome used as a tonic in Ayurveda and Chinese medicine, with animal research only and no human safet…
Pueraria mirifica (kwao krua) root: a strongly estrogen-like Thai herb. What small menopause studies show, plus hormone-sensitive condition, bleeding and product-quality…
Milk thistle (Silybum marianum) and silymarin: what NIH and a large US trial found for liver disease and blood sugar, plus allergy, quality and pregnancy points.
Cranberry (Vaccinium macrocarpon) and urinary tract infections: what Cochrane and NIH found for prevention, why it is not a treatment, and warfarin and kidney stone caut…
Uva ursi (bearberry leaf, Arctostaphylos uva-ursi): the EU traditional-use monograph, its limits on kidney disease, men, children and pregnancy, and the lack of trials w…
Burdock root (Arctium lappa): EU traditional-use findings, the lack of controlled human trials, belladonna contamination reports, and daisy-family allergy cautions.
Juniper berry (Juniperus communis): the 2023 EU traditional-use monograph for urinary flushing and digestion, with kidney, fluid, pregnancy and children cautions.
Goldenrod (Solidago virgaurea): the EU traditional-use monograph for minor urinary complaints, why it is not trial-proven, and heart, kidney, diuretic and daisy-family c…
Cleavers (Galium aparine): what the plant is, its traditional skin and wound use, why human evidence is not found, and what safety information we could not locate.
Pumpkin seed and seed oil (Cucurbita pepo): the EU traditional-use status for urinary symptoms, what prostate and other trials found, and allergy and pregnancy cautions.
Bupleurum root (Bupleurum chinense, chai hu): what research shows, why liver-injury and lung reports matter, and what to know about the Xiao Chai Hu Tang formula.
Couch grass rhizome (Elymus repens, also Agropyron repens): what EU regulators say about its traditional use for flushing the urinary tract, the thin evidence, and the c…
Corn silk (Zea mays styles and stigmas): traditional urinary and diuretic use, thin trial evidence on blood pressure and blood sugar, and cautions for kidney disease, wa…
Buchu leaf (Agathosma betulina): a South African herb long used for urinary complaints, why a German expert panel did not recommend it, and the liver, pregnancy and qual…
Chanca piedra (Phyllanthus niruri): what reviews show for kidney stones and chronic hepatitis B, plus pregnancy, medicine and kidney or liver cautions.
Punarnava (Boerhavia diffusa), an Ayurvedic root herb used for kidney and water-retention claims: what the sources say, why human evidence is thin, and kidney, pregnancy…
Kutki root (Picrorhiza kurroa), a bitter Ayurvedic herb sold for the liver: what the few small trials show, pregnancy caution, endangered wild stocks and quality concern…
Imperata (bai mao gen, cogongrass rhizome): traditional use for bleeding and urination, a small human diuretic trial that found no effect, and cautions on potassium, kid…
Alisma (ze xie, water plantain rhizome): a Chinese medicine herb used as a diuretic and for blood fats. See what research shows, kidney cautions and quality issues.
Birch leaf (Betula pendula, B. pubescens): what EU regulators say about its traditional use for urinary flushing, plus pollen-allergy, fluid, heart, kidney and pregnancy…
Gardenia fruit (zhi zi, Gardenia jasminoides): what is known about traditional use, the thin human evidence, liver cautions from animal studies, and its use as a natural…
Hydrangea root (Hydrangea arborescens): traditionally used for kidney and bladder stones, with no human trials found, plus a cyanide-type compound, lithium and pregnancy…
Gravel root (Joe-Pye weed, Eutrochium purpureum): an old urinary-stone remedy from North America. Liver-toxic alkaloid risk is likely, and proper human evidence was not …
Java tea (cat's whiskers, Orthosiphon aristatus): what EU regulators and trials say about urinary flushing, plus the heart and kidney fluid warning, pregnancy and potass…
Boldo leaf (Peumus boldus): what EU regulators say about its traditional use for indigestion, plus liver, gallstone, pregnancy and ascaridole safety cautions.
Pipsissewa (prince's pine, Chimaphila umbellata): what we could and could not verify about its folk uses, the lack of human trials, the threatened status of wild plants,…
Lovage root (Levisticum officinale): the 2012 EU traditional-use monograph for urinary flushing, plus sun-sensitivity, kidney, fluid, pregnancy and children cautions, an…
Restharrow root (Ononis spinosa): the EU traditional use for flushing the urinary tract, why it is not for people told to limit fluids, and what research does and does n…
Cassia seed (jue ming zi, Senna obtusifolia): a traditional Chinese seed with laxative-type anthraquinones; what human evidence exists, and liver, kidney and pregnancy c…
Capillary wormwood (Artemisia capillaris, yin chen hao): its Chinese medicine use for jaundice, what the evidence is, and the liver-injury case reports and allergy cauti…
Heather or ling (Calluna vulgaris) is a traditional urinary tea herb that contains arbutin. We found no human trials, no EU herbal monograph, and only lab studies.
Turmeric (Curcuma longa) rhizome: what NIH and European regulators say, what joint and liver studies found, why some curcumin products are linked to liver injury, and wh…
Boswellia serrata gum-resin extract (frankincense family): what research on knee osteoarthritis found, what NIH says about safety, and the bleeding and medicine cautions…
Devil's claw root (Harpagophytum procumbens): Southern African traditional use, what trials and the EU herbal committee found for joint and back pain, stomach and gallst…
White willow bark (Salix alba): the salicin and aspirin link, what trials found for back pain and osteoarthritis, and the aspirin allergy, children, blood-thinner and ul…
Arnica (Arnica montana) flower: skin use for bruises and sore joints, what trials found, why swallowing it is unsafe, and the daisy-family allergy, blood thinner and hom…
Comfrey (Symphytum officinale): why swallowing it is linked to liver injury, what the FDA, Health Canada guidance and EU regulators say, and what is known about creams a…
Calendula (Calendula officinalis), pot marigold flowers: traditional skin use, what wound and radiation-skin trials found, and the daisy-family allergy and pregnancy cau…
Witch hazel (Hamamelis virginiana): how the distilled water differs from bark and leaf products, what EU and US rules say about skin and hemorrhoid use, and the allergy …
Neem (Azadirachta indica): why swallowing neem oil has caused severe poisoning in children and adults, what research shows for mouth rinses and skin, and Ayurvedic backg…
Cayenne pepper and capsaicin: what reviews found for skin patches and creams, what the EU says about muscle-pain products, and cautions for eyes, broken skin, medicines …
Plantain leaf (Plantago major): what this common leaf is, how it differs from psyllium and the cooking fruit, and what trials, animal studies and EU monographs say about…
Yarrow (Achillea millefolium): what the EU says about its traditional uses for appetite, cramps and small wounds, why daisy-family allergy matters, and cautions for preg…
Chickweed (Stellaria media): a common garden plant with traditional uses but, in the sources we read, only lab and animal research and no human trials or safety data.
Myrrh resin (Commiphora myrrha): what the EU says about mouth and skin use, what small trials found, and warfarin, pregnancy, allergy and quality cautions.
Sarsaparilla root (Smilax species): what we could and could not verify about psoriasis and gout claims, plus kidney, pregnancy, digoxin and lithium cautions.
Bhringraj (Eclipta prostrata), an Ayurvedic leaf herb used in hair oils: what the sources say about hair and liver claims, and why human evidence is still very thin.
Meadowsweet (Filipendula ulmaria): a salicylate-containing flowering herb used in tea for colds and aching joints. Read what EU regulators say, what trials are missing, …
Corydalis yanhusuo tuber (yan hu suo): what is known about pain and sleep claims, plus the liver-injury reports, drowsiness, heart-rhythm and pregnancy cautions to know …
Dragon's blood (sangre de grado) is the red latex of Croton lechleri. See what the prescription drug crofelemer proves, what the raw sap lacks, and key safety cautions.
Chuanxiong rhizome (Ligusticum chuanxiong), a Chinese herb used for headache and circulation: what trials show, blood-thinner and pregnancy cautions, and what is not pro…
Nirgundi (Vitex negundo), the Chinese chaste tree leaf used in Ayurveda for joint pain: what the few human trials found, skin-reaction and pregnancy cautions, and how it…
Heartsease or wild pansy (Viola tricolor): an EU traditional herbal tea and skin wash for mild seborrhoeic skin conditions, with no human trials found and clear cautions.
Bakuchi or babchi seed (Psoralea corylifolia, bu gu zhi): skin-sensitising psoralens, vitiligo use with little proof, and published liver injury case reports.
Achyranthes root (niu xi, Achyranthes bidentata): what the sources say about joints and bones, why pregnancy caution matters, and how it differs from Cyathula.
Dipsacus root (Dipsacus asper, xu duan, Japanese teasel): traditional bone and tendon use, why human fracture and osteoporosis evidence is missing, and how it differs fr…
Angelica pubescens root (du huo): its traditional use for joint pain, the thin human evidence, and the sun-sensitivity, poisoning and pregnancy cautions to know first.
Notopterygium (qiang huo) root: its traditional use for upper-body joint pain and colds, the lack of human trials, a possible drug-interaction signal, and concerns about…
Blue flag rhizome (Iris versicolor): a wetland iris whose root is irritating and can cause vomiting, with no good human trials behind its traditional skin and lymph uses.
Chaparral (creosote bush, Larrea tridentata): reports of serious liver injury, no proven benefit, and what the sources say about tea, capsules, tinctures and skin produc…
Sausage tree (Kigelia africana): an African fruit used in skin creams. What the sources say, why the raw fruit is toxic, and why human trials are missing.
Chuchuhuasi bark (Maytenus macrocarpa and look-alike Amazon trees): traditional use for rheumatism and colds, why no human trials exist, and the safety unknowns.
Tepezcohuite bark (Mimosa tenuiflora): a Mexican skin-healing bark with mixed trial results for leg ulcers, birth-defect warnings in animals, and a DMT-containing, contr…
Jewelweed (Impatiens capensis), a North American wildflower used as a folk poison-ivy remedy: what the small controlled trials found, and cautions about eating it.
Thunder god vine root (Tripterygium wilfordii): NCCIH and published reviews on rheumatoid arthritis, plus the serious kidney, liver, fertility, immune and birth-defect r…
Stephania (fang ji, Stephania tetrandra) root: the mix-up with Aristolochia that caused kidney failure and cancer, what tetrandrine research shows, and what to check bef…
Qin jiao (large-leaf gentian root, Gentiana macrophylla) is used in Chinese medicine for joint pain; the research we read is animal and lab work, with no human trials fo…
Figwort (Scrophularia nodosa): a traditional skin herb with iridoid compounds, no human trials found, thin safety data and a heart caution from practitioner and older re…
Taxillus (sang ji sheng, Taxillus chinensis): a parasitic Chinese mistletoe whose chemistry depends on its host tree. What reviews say, why the host matters for safety, …
Sariva or Indian sarsaparilla root (Hemidesmus indicus): a traditional Ayurvedic blood and skin herb with lab and animal findings but no human trials found, and unanswer…
Rasna (Pluchea lanceolata) is an Ayurvedic leaf herb used for joint pain; the human research is small or unfinished, and daisy-family allergy is a reason for care.
Cissus quadrangularis stem: what small trials show for bone, joints and weight, and the cautions on blood sugar, pregnancy, surgery and unproven hormone claims.
Ground elder or goutweed (Aegopodium podagraria): a traditional gout and arthritis plant with no human trials, plus the real danger of confusing it with poisonous look-a…
Autumn crocus (Colchicum autumnale) is a poisonous plant that contains colchicine, the gout drug. Why the margin is narrow, how it gets mistaken for wild garlic, and who…
Green tea (Camellia sinensis): what NIH and Cochrane found for weight, cholesterol and heart health, and why extract capsules have been linked to liver injury and drug i…
Rose hips (Rosa canina): what trials of rose hip powder found for osteoarthritis pain, how much vitamin C the fruit contains, and what safety information we could and co…
Sea buckthorn (Hippophae rhamnoides): what small trials found for cholesterol, vaginal dryness, dry eye and burns, how oil and cream studies differ, and what safety data…
Bilberry (Vaccinium myrtillus): what reviews found for night vision, eye strain and blood sugar, what EU regulators accept for the fruit, and what safety information we …
Black seed (Nigella sativa): what the seed is, how it has been used traditionally, what blood pressure and blood sugar trials found, and the medicine, skin and pregnancy…
Goji (wolfberry, Lycium barbarum and Lycium chinense): traditional use, the limited human research, warfarin bleeding reports and food-allergy cautions, with sources.
Noni (Morinda citrifolia) juice and fruit: traditional use, why human evidence is thin, liver injury reports, potassium cautions for kidney disease and medicine interact…
Maqui berry (Aristotelia chilensis): what the fruit is, what a 2026 review of 12 human trials found for blood sugar, dry eye and other uses, and what is unknown about sa…
Moringa leaf (Moringa oleifera): what small human trials and reviews found on blood sugar, blood pressure and breast milk, plus pregnancy, medicine and allergy cautions.
Acai fruit (Euterpe oleracea): what NIH says about the very limited human research, weight-loss marketing, raw-juice Chagas risk, blood sugar and MRI cautions.
Mangosteen fruit rind (Garcinia mangostana): what the sources say about gum, blood sugar and other uses, plus cautions on medicines, cancer treatment, kidney disease and…
Baobab fruit pulp powder (Adansonia digitata): what the few human trials found on blood sugar and iron, what regulators allow as a food ingredient, and what is unknown a…
Chia seed (Salvia hispanica): what trials found on blood pressure, cholesterol and weight, and why dry seeds can block the throat, plus allergy and medicine cautions.
Yerba mate leaf (Ilex paraguariensis): caffeine content, what IARC says about very hot drinks and esophageal cancer, what trials found, and EU cautions on pregnancy and …
Rooibos leaf (Aspalathus linearis), red and green: what small human studies show, plus liver-case, transplant-drug, chemotherapy and hormone-sensitive-cancer cautions.
Camu camu fruit (Myrciaria dubia): how much vitamin C it holds, what the few small human studies found, and the vitamin C safety points that still apply to powders and c…
Guayusa leaf (Ilex guayusa): a caffeine-containing Amazonian tea. What traditional use, small trials and lab work show, and the caffeine, pregnancy and blood pressure ca…
Rose petals (Rosa damascena): what the EU says about the traditional mouth and skin use, what small trials found for constipation and calming scent, and the pregnancy an…
Chrysanthemum flower (Chrysanthemum morifolium, ju hua tea): traditional use in Chinese dietary medicine, the very thin human research, and the daisy-family allergy caut…
Monk fruit (Siraitia grosvenorii, luo han guo): what the FDA and EFSA say about its sweet extract, what little human research exists on blood sugar, and who should ask f…
Kokum (Garcinia indica), the sour Indian fruit rind and seed butter: what is known about garcinol and HCA, why human evidence is thin, and the liver caution borrowed fro…
Alfalfa (Medicago sativa) leaf, sprouts and seeds: what sources say about cholesterol, plus lupus flare, sprout food-poisoning, warfarin, estrogen-like and pregnancy cau…
Irish moss or sea moss (Chondrus crispus): what we found on iodine, heavy metals, carrageenan and thyroid cautions, and why the popular sea moss gel claims are not backe…
Spirulina (Arthrospira platensis), a blue-green alga sold as powder and tablets: what trials show for cholesterol and blood pressure, plus contamination, allergy and B12…
Chlorella (Chlorella vulgaris), a green microalga sold as tablets and powder: what trials found, plus vitamin K and warfarin, allergy, contamination and immune-condition…
Wheatgrass (Triticum aestivum) young-leaf juice and powder: what small trials in ulcerative colitis show, plus gluten, raw-juice contamination and nausea cautions.
Honeybush (Cyclopia species) is a South African tea. See what reviews and lab work report on mangiferin and plant oestrogens, and why human evidence is thin.
Oregano (Origanum vulgare): food versus supplement amounts, what small studies found, a reported blood-thinner interaction, pregnancy and allergy cautions, and oil of or…
Thyme (Thymus vulgaris): what EU regulators and trials say about thyme for chesty coughs, why thyme-ivy syrups are product-specific, and pregnancy, children and mint-fam…
Sweet basil (Ocimum basilicum): food use versus extracts, three small trials, the estragole question raised by EU regulators, pregnancy cautions, and holy basil compared.
Parsley (Petroselinum crispum): a food herb with mostly lab and animal research, plus cautions on the essential oil, warfarin and vitamin K, oxalate, pregnancy and aller…
Cumin (Cuminum cyminum): a food spice with mixed trial results for blood sugar and cholesterol, allergy and skin cautions, and pregnancy advice to stay at food amounts.
Coriander and cilantro (Coriandrum sativum): one small diabetes trial, no human evidence for the heavy-metal detox claim, allergy and skin cautions, and the soap-taste g…
Cloves (Syzygium aromaticum) as a spice and a traditional toothache remedy: what the EU assessment found, how thin the trial evidence is, and why clove oil can poison yo…
Black pepper (Piper nigrum) and its main compound piperine: how it can raise blood levels of other substances and medicines, what trials show, and the gap between season…
Star anise (Illicium verum) as a spice and traditional herb: one small mouthwash trial, and why star anise tea has caused seizures in infants, partly through toxic look-…
Culinary sumac (Rhus coriaria) is a tangy spice, not poison sumac. Trials and meta-analyses on blood sugar, blood pressure and cholesterol are mixed, and safety data are…
Celery seed (Apium graveolens) is studied for blood pressure and uric acid, but trials are small and gout evidence is animal-only. Celery allergy can be severe.
Horseradish (Armoracia rusticana) is a pungent root condiment. Human trials test it only inside a nasturtium combination for bronchitis and cystitis, and other safety da…
Mustard seed (Brassica juncea and Sinapis alba) in food and folk medicine: reports of skin burns from mustard plasters, food allergy, and the limited research on pain an…
Lemongrass (Cymbopogon citratus) in cooking, tea and aromatherapy: what small trials show, one trial of tea and kidney function, and cautions for pregnancy, kidney disea…
Dill (Anethum graveolens) is a kitchen herb and seed. What small trials found for cholesterol, insulin resistance, period pain and labor, plus allergy and safety limits.
Nutmeg (Myristica fragrans) is a kitchen spice that can poison people in large amounts. What poison-center reports show, what research exists, and when to call Poison He…
Galangal rhizome (Alpinia galanga): a Southeast Asian spice with little human research, a few small trials, and unanswered questions on medicines, pregnancy and safety.
Cilantro (Coriandrum sativum leaf): why the heavy-metal "detox" claim lacks human proof, real food-safety risks such as Cyclospora and lead, allergy, and the thin resear…
Long pepper, or pippali (Piper longum): its piperine content, why it may change how medicines are absorbed, and the near-absence of human trials on the fruit itself.
Ajwain, or carom seed (Trachyspermum ammi): what small trials and lab studies show, why its thymol-rich oil needs care, and what we could not verify on pregnancy and med…
Asafoetida (hing), the resin of Ferula assa-foetida: a serious infant blood-oxygen warning, what small trials show for indigestion and IBS, and what we could not verify.
Plants of North America with documented Native American medicinal use, what health agencies say about them today, and how to treat Indigenous plant knowledge with care.
How European herbal medicine is organized today: EU herbal monographs, traditional-use registration, pharmacopoeias and phytotherapy, with devil's claw and pelargonium a…
A careful overview of African herbal medicine: what WHO says about traditional medicine in Africa, devil's claw as a case study in research, regulation and sustainable h…
Latin American and Caribbean herbs in context: cat's claw and pau d'arco from the Amazon, survey records of Caribbean bush remedies, and the cautions that go with them.
A short guide to where Ayurvedic, Chinese, Unani, Kampo, Siddha and Tibetan herbs are covered on this site, plus the shared safety points health agencies raise about the…
Mugwort (Artemisia vulgaris) herb: traditional uses, what little human research exists, the Cochrane review of mugwort moxibustion for breech babies, and pregnancy and a…
Rehmannia root (Rehmannia glutinosa, di huang): raw versus prepared forms, what small and mixed-quality trials show, and honest safety gaps on medicines, pregnancy and d…
Eyebright (Euphrasia officinalis): why EU regulators advise against homemade eye washes, what small trials found for conjunctivitis, and what is unknown about other uses.
Bladderwrack (Fucus vesiculosus), a brown seaweed: why its iodine can disturb the thyroid, the arsenic and heavy-metal concern, and what EU regulators and trials say abo…
Phellodendron bark (Phellodendron amurense, huang bai): what small trials of branded blends found, why its berberine matters for newborns, pregnancy and medicines, and w…
Ligustrum (glossy privet fruit, nu zhen zi): a Chinese-medicine tonic with very little human research. What sources say about use, safety, pregnancy and plant look-alike…
Graviola or soursop (Annona muricata): why cancer claims are unproven in people, and the nerve-toxicity and parkinsonism concerns linked to regular fruit, juice and leaf…
Suma, or Brazilian ginseng (Pfaffia paniculata): what we found on traditional use, the thin human evidence, the ecdysterone sports claims, and safety unknowns.
Manjistha root (Rubia cordifolia, Indian madder): traditional blood and skin herb with almost no human trials, and a safety warning about related madder (Rubia tinctorum…
Rue (Ruta graveolens): why this garden herb can burn skin in sunlight and has caused severe poisoning and deaths when swallowed to end a pregnancy, and what little resea…
Tansy (Tanacetum vulgare): a thujone-containing plant that sources call unsafe to swallow, with no proven medical benefit, plus pregnancy, seizure and allergy cautions.
Sandalwood heartwood and oil (Santalum album): what small studies found for calm, skin and warts, why the oil is not for swallowing, skin allergy, fake oils and overharv…
Kratom leaf (Mitragyna speciosa) acts on opioid receptors. What FDA, NIH, WHO and poison-center data say about dependence, deaths, liver injury, 7-OH products and legal …
Betel nut (areca nut, Areca catechu): why health agencies link chewing it to oral cancer, mouth scarring and dependence, with pregnancy and medicine cautions. Informatio…
Ophiopogon (mai dong, Ophiopogon japonicus): traditional Chinese use for dry cough and the heart, what trials of Shenmai products really show, and cautions about injecti…
Polygonatum rhizome (huang jing, Solomon's seal; Polygonatum sibiricum): used in Chinese medicine for centuries, with one small sleep trial and mostly lab research behin…
Dendrobium (shi hu, Dendrobium officinale) is an orchid stem used in Chinese medicine; human evidence is small, products are often mixed with other species, and wild pla…
Calamus or sweet flag (Acorus calamus) rhizome: animal studies link its asarone to liver cancer, US law bars it from food, and human evidence of benefit is missing.
Bala (country mallow, Sida cordifolia): a plant the FDA names as a source of ephedrine, the stimulant banned in US supplements. What the sources say about heart risk, qu…
Bayberry or wax myrtle (Myrica cerifera) root bark: no good evidence it works, and consumer references warn about liver, cancer-risk and blood pressure concerns.
Poke root (pokeweed, Phytolacca americana) is a poisonous plant, not a safe herbal remedy. What the sources say about root, berry and leaf poisoning, and who to call.
Apricot kernel (Prunus armeniaca): why raw kernels can cause cyanide poisoning, what "vitamin B17" and laetrile really are, and what EFSA, the FDA and Cochrane found.
Chinese asparagus root (tian men dong, Asparagus cochinchinensis): its traditional use for dry cough, why human evidence is missing, and cautions on drug enzymes and loo…
Kelp (Saccharina japonica, also Ascophyllum nodosum), a brown seaweed: why its iodine can upset the thyroid, the arsenic concern, and how little human evidence supports …
Bitter kola seed (Garcinia kola): a West African chewed seed used for cough and liver complaints. What the few human trials and many animal studies show, and the safety …
Ashitaba (Angelica keiskei): what EFSA and human trials say about the leaf, stem sap and chalcones, plus cautions on blood clotting, pregnancy, allergy and look-alike An…
Sassafras (Sassafras albidum): why root bark and oil carry a cancer warning because of safrole, the US food ban, safrole-free extract, and how filé powder from leaves di…
Cornelian cherry fruit (shan zhu yu, Cornus officinalis): a Chinese-medicine fruit in Liu Wei Di Huang Wan. What human and lab research shows, and which cautions apply.
Khat leaf (Catha edulis) is an amphetamine-like stimulant chewed in East Africa and Yemen. What the DEA and medical reviews say about dependence, heart, liver and mental…
Wild ginger (Asarum canadense) is not true ginger. Its rhizome can contain aristolochic acid, which the FDA treats as a kidney toxin and carcinogen. See the evidence and…
Mayapple (Podophyllum peltatum) is a poisonous woodland plant, not a herbal remedy: its root resin is the source of wart drugs, and poisoning can be severe. Information …
Bloodroot (Sanguinaria canadensis): why black salve cancer products cause tissue destruction, the FDA warnings, the old mouthwash link to white mouth patches, and what r…
Borage (Borago officinalis): why its leaf and flower carry liver-toxic pyrrolizidine alkaloids, what research says about the seed oil, and the foxglove look-alike and pr…
Devil's club bark (Oplopanax horridus): its place in Pacific Northwest and Alaska Indigenous medicine, why blood-sugar claims are not backed by trials, and diabetes-medi…
Cornflower (Centaurea cyanus), the blue petals in teas and cosmetics: old eye-wash use and why it is a sterility risk, daisy-family allergy, and the thin lab-only eviden…
Aconite (monkshood, Aconitum carmichaelii) is a highly poisonous root: how it harms the heart and nerves, what processing (fuzi) changes, and what research does and does…
Belladonna or deadly nightshade (Atropa belladonna) is a poisonous plant, not a safe home remedy. Its dangers, why berries tempt children, and what sources say.
Agarwood, oud or chen xiang (Aquilaria malaccensis): why there are no human trials, what lab and animal studies suggest, smoke and fake-product cautions, and its protect…
Anemarrhena (zhi mu, Anemarrhena asphodeloides): a Chinese medicine rhizome whose research is almost all in mice and cells, with no good human safety data.
Trichosanthes root (tian hua fen, Trichosanthes kirilowii): a Chinese medicine root whose protein, trichosanthin, was used to end pregnancies and can cause severe allerg…
Saptaparna or devil's tree bark (Alstonia scholaris): its traditional use for malaria and fever, how thin the human evidence is, and cautions for pregnancy, liver and bl…
Calotropis (arka, Calotropis gigantea) is a toxic plant, not a safe herbal remedy. Heart-poison compounds in all parts, caustic latex that injures the eye, and what rese…
Patha (velvetleaf, Cissampelos pareira) root: what the sources say about its alkaloids, traditional uses and very thin human evidence, plus anesthesia and pregnancy caut…
Great burnet root (Sanguisorba officinalis, di yu): used in Chinese medicine for bleeding and scalds, with thin human evidence and little published safety data.
Poison hemlock (Conium maculatum) is a deadly plant, not a remedy. Why it is easily mistaken for wild carrot or parsley, what poisoning looks like, and who to call.
Lycium root bark (di gu pi, Lycii Cortex): a Chinese medicine herb, not goji berries. What lab and animal studies show on blood sugar and pressure, and why human evidenc…
Clubmoss (Lycopodium clavatum): why the spore powder should not be inhaled, how it differs from Huperzia and huperzine A, and why proper evidence of benefit is thin.
Teas, tinctures, extracts, capsules and powders are different products. See why a study of one form does not carry over to another, with examples from NCCIH and EMA.
What infusion, decoction, maceration and herbal tea mean, why the method changes what is in the cup, and what the sources say about safety. Definitions only, no recipes.
What tincture, fluid extract and glycerite mean on a label, what the EU valerian monograph shows about solvents and ratios, and why alcohol content matters. No making in…
What herbal capsules, tablets and powders are, what a 2025 lab study found about their contents and breakdown, and why a tea study does not apply to a capsule.
What standardized herbal extract, marker compound and extract ratio mean, what testing of real products found, and why an extract study does not apply to a tea.
What herbal salves, oils, creams and poultices are, what research found for topical aloe, arnica, comfrey and others, and the skin-allergy and broken-skin cautions to kn…
Does it matter whether a herb is fresh, dried or freeze-dried? What a drying review, EU guidance and NCCIH say, where evidence is missing, and why raw plant parts can be…
Herbal syrups, lozenges and gummies: what the sources say about sugar, honey and infants, children and candy-like products, and why evidence for these forms is thin.
What a proprietary herbal blend hides, why many ingredients make interactions harder to judge, and a plain checklist for reading a multi-herb product label with a pharma…
Why a herb eaten as food is not the same as a herb supplement: worked comparisons for turmeric, garlic, chamomile and ginger from NCCIH, FDA and a liver-injury case seri…
Herb safety and medicine interactions in plain language: urgent warning signs first, then NIH-sourced cautions for twelve herbs and links to guides on blood thinners, an…
How herbs can change the way medicines work, in plain language: liver enzymes, transporters, additive effects, and why St. John's wort is the best-documented example.
Which herbs have been linked to bleeding or changed warfarin effects, what NCCIH, MedlinePlus, the NHS and a systematic review say, and who to call: your anticoagulation…
Why St. John's wort should not be combined with antidepressants without a clinician: serotonin syndrome signs first, what NCCIH, MedlinePlus and the NHS say, and where t…
Why people on transplant or other immune-suppressing medicines should ask their transplant team before any herb: St. John's wort and cyclosporine, echinacea, tacrolimus …
What sources say about licorice, hawthorn, fenugreek, garlic, green tea and St. John's wort alongside diabetes, blood pressure, cholesterol and heart medicines, with lim…
What cancer centers and NIH say about herbs and antioxidant supplements during chemotherapy and other cancer treatment, which interactions are documented, and why the on…
Which botanicals have been linked to liver injury, what NCCIH and NIH LiverTox say about each, the warning signs to act on, and why adulteration and product form matter.
What the National Kidney Foundation, NCI and NIH say about herbs and kidney disease: aristolochic acid, potassium, interactions, and why a nephrologist should review eve…
Which herbs sources link to bleeding or anesthesia effects, the stop-before-surgery timing that NCCIH and Memorial Sloan Kettering state, and why the surgical team must …
How allergic reactions to herbs happen, why people allergic to ragweed or daisies may react to chamomile or echinacea, what is known about mint-family herbs, and when to…
Whom to call first for plant or herb poisoning, which plants and herbal products sources describe as toxic (awareness only), and how toxic herbs differ from products tha…
Ephedra (ma huang) was banned from US dietary supplements in 2004 over serious heart and brain harms. See what the FDA found, what trials showed, and other restricted he…
Bitter orange (synephrine) and yohimbe supplements are sold for weight loss and energy. See what trials found, the heart and blood pressure reports, label problems and w…
Pyrrolizidine alkaloids in comfrey, coltsfoot, borage and butterbur can injure the liver. See what the EU committee and other sources say, what PA-free means and who is …
Aristolochic acid in some Aristolochia herbs has caused kidney failure and urinary tract cancers. See where it was found, how substitution happened and what to ask a cli…
Chaparral and germander have well-documented reports of liver injury, and other herbs have been linked too. See the case evidence, skullcap mix-ups, warning signs and wh…
A quick reference of herbs and the medicines and conditions they are reported to affect, from blood thinners to pregnancy, with what each source says and links to full p…
A goal-by-goal index of what research says about herbs for sleep, mood, colds, digestion, heart, hormones, joints and more, with links to each page and the serious cauti…
What NIH, a 2015 review, a 2024 valerian review and EU regulators say about valerian, chamomile, hops, passionflower and lavender for sleep, with cautions on sedatives, …
What NIH says about chamomile, lavender, passionflower, valerian and kava for anxiety and stress, how strong the evidence is, and where the liver, sedative and pregnancy…
What NIH and systematic reviews say about St. John's wort and saffron for low mood and depression, the limits of the evidence, and the serious medicine interactions to k…
What NIH, Cochrane and other reviews say about echinacea, elderberry, pelargonium, andrographis and honey for colds, flu and cough, plus when a clinician should see you …
What NIH and a 2024 review say about butterbur, stinging nettle and other herbs for hay fever, why plant allergy and liver cautions come first, and the signs of a severe…
What research and official bodies say about ginger, peppermint and other herbs for nausea, irritable bowel syndrome, indigestion, heartburn and bloating, with warning si…
What EU, US and UK health sources say about senna, cascara and psyllium (ispaghula) for constipation, why stimulant herbs are for short use only, and who should not take…
What trials and official bodies say about feverfew, butterbur and peppermint for headache and migraine, including why butterbur is no longer recommended and when a heada…
What the North American Menopause Society, Cochrane, NIH and EU regulators say about black cohosh, red clover, sage and chasteberry for hot flashes, with liver and hormo…
What Cochrane, NIH and EU regulators found for ginger, fennel, chasteberry and other herbs for period pain and PMS, with warning signs and hormone-medicine cautions firs…
A claim check of herbs marketed for PCOS and hormone balance, covering spearmint tea, chasteberry and herbal formulas, what trials show, what health agencies list as tre…
What research and European regulators say about saw palmetto, nettle root, pygeum, cranberry and uva ursi for prostate and urinary symptoms, and when to see a clinician …
What reviews and health agencies found for hibiscus, garlic, hawthorn, green tea and sage on blood pressure and cholesterol, plus the licorice and red yeast rice warning…
What NCCIH, Cochrane and other reviews found for cinnamon, bitter melon, fenugreek, gymnema, milk thistle and garlic in type 2 diabetes, and why herbs never replace diab…
What NCCIH, EU regulators and reviews found for turmeric, boswellia, devil's claw and willow bark in joint pain and osteoarthritis, with liver, bleeding and tainted-prod…
Claim check on herbs marketed for liver health, detox or cleansing: what milk thistle and artichoke trials found, and which herbs have documented liver injury reports.
What Cochrane, NCCIH and meta-analyses found for ginkgo, bacopa and sage on memory, focus and dementia, with bleeding, thujone and ginkgo-seed warnings up front.
What research shows for aloe, tea tree oil, calendula, witch hazel and Chinese herbal formulas on acne, eczema, burns and wounds, with the signs of infection that need a…
Do herbs and botanical fat burners help with weight loss? What reviews of green tea and other supplements found, plus hidden-drug, stimulant and liver risks.
What research shows for Asian ginseng, rhodiola, ashwagandha and caffeine-containing herbs on energy and fatigue, with cautions and when ongoing tiredness needs a clinic…
Can herbs help asthma, bronchitis or "lung health"? What NCCIH and reviews found, why herbs never replace inhalers, and when breathing trouble is an emergency.
Do echinacea, elderberry, garlic, andrographis and other herbs "boost" the immune system? What reviews of colds and flu found, what they did not measure, and safety poin…
What NIH, the NHS and other official sources say about herbs and herbal teas in pregnancy, which herbs they flag, and why talking to your obstetric team comes first.
What NIH and the NHS say about herbs while breastfeeding, including fenugreek for milk supply, herbs with infant warnings, and what is simply not known.
What the NHS, NIH and European regulators say about herbal products for children and teens, including chamomile, echinacea, elderberry and peppermint, and when to call P…
Why herbs deserve extra care with many medicines, falls and kidney problems, based on NIA, NCCIH, NHS and National Kidney Foundation statements.
What WADA, USADA and NIH say about herbal supplements for athletes, which plants contain prohibited substances, contamination risk and what we could not verify about tri…
What the sources say about plant estrogens, black cohosh, red clover, hops and soy for people with breast, uterine or prostate cancer or endometriosis, and why to ask th…
Why some regulators advise caution with echinacea and other immune-stimulating herbs in autoimmune disease, what a 2025 review found, and what to ask your specialist bef…
What case reports and reviews say about St. John's wort, ginseng, ephedra and other herbs in mania, psychosis and seizure conditions, and when to get urgent help.
How to use a pharmacist and one complete medicine list when you take several medicines, with the herb-medicine pairs official sources document and what is only theoretic…
How to judge herbal product quality and labels: plant name and part, extracts, testing, contamination and what a quality claim can and cannot tell you.
A plain walk through an herbal supplement label: species, plant part, extract details, amount per serving, other ingredients and claims, and what each part can and canno…
Why the scientific plant name and the plant part on a herbal label matter, with documented examples from chamomile, echinacea, ginkgo, black cohosh and goldenseal.
What "standardized to" means on a herbal label, what a marker compound is and is not, and what studies found when they compared labels with measured contents.
What testing and certificates of analysis for herbal products can show, what they cannot, and what rules and studies say, described generally without naming programs.
What surveys and reviews found about lead and other metals, pesticide residues, molds and microbes in herbal products, with the limits of each study and where evidence i…
Studies and regulators describe herbal products that hold other plants, fillers, dyes or hidden drugs. See what was found, why the numbers differ and what the tests cann…
Organic, wildcrafted and sustainably harvested mean three different things on an herb label. See how US rules and one wild-harvest standard define them, and what they do…
Some plants sold as herbs come from shrinking wild populations. See what the sources say about goldenseal, American ginseng, rhodiola and others, and the part Indigenous…
How storage, humidity and mold relate to dried herbs and herbal products, what mold toxins are, and why the sources we read give no safe way to rescue spoiled herbs or a…
Learn the warning signs FDA and NCCIH describe for herbal products, from miracle-cure claims to hidden drugs, and how to check a product without relying on rankings or r…
Where research on medicinal herbs is thin: short trials, unclear products, safety questions in pregnancy and with medicines, and what to do as a reader.
How much research exists on herbs, what a PubMed count does and does not show, how to read herb studies, and where the gaps are. Includes an evidence snapshot for 26 her…
How some medicines began as plants, from willow bark and aspirin to artemisinin, what pharmacognosy is, and why a medicine made from a plant is not the same as the plant.
How controlled herb trials are built, why herbs are harder to test than a single-compound drug, and why two trials of the same herb can reach different results.
Why studies of the same herb can disagree, from plant species, parts and growing conditions to extraction and the amounts of marker compounds found in products.
What an herbal monograph is, how EU (EMA/HMPC), WHO, German Commission E and pharmacopoeia monographs differ, and why a monograph is not a recommendation for a person.
How the EU and UK let some herbal medicines be registered on the basis of long-standing use, what that does and does not prove, and what the label mark means.
How US law treats herbal supplements: what DSHEA changed, what FDA does and does not review, who polices advertising, and what the label disclaimer means.
What biopiracy and benefit sharing mean in herbal medicine, what the Nagoya Protocol and the 2024 WIPO treaty say, and why respect for knowledge keepers matters.
What ethnobotany and ethnopharmacology are, how traditional plant uses are recorded in surveys, how they are later tested in labs and trials, and why a record is not adv…
A PubMed snapshot of how many studies mention 26 popular herbs, what the counts can and cannot tell you, and why a bigger number does not mean a herb works.
What official sources say about how long herbs have been studied, why one number cannot fit every product, and the questions to take to a pharmacist before using one.
Free official resources for looking up a herb (NCCIH, MedlinePlus, LiverTox, LactMed, FDA), what each can and cannot tell you, and why a pharmacist is the last step.
A checklist of questions to take to a pharmacist or clinician before using a herb, grouped by medicines, health conditions, surgery, pregnancy and children, with the rea…
A plain guide to reading a herb study or news headline, using NCCIH guidance: animal versus human studies, study size, blinding, small effects, funding and what one stud…
A plain table to copy or print that lists medicines, herbs and supplements, health conditions and upcoming procedures, so a pharmacist or clinician can check them togeth…
A quick-reference table matching common herb names to scientific names and plant families for every herb profile in this library, checked against the GBIF plant name dat…
Index of side-by-side herb guides, plus an at-a-glance table of what NIH and the EU herbal committee say. Each guide answers one question, with no rankings and no winner…
Turmeric is the plant, curcumin is one component. How kitchen turmeric, root powder and curcumin extracts differ, what NIH says about evidence, and the liver warning.
Ginger and turmeric are both rhizomes in the ginger family. What NIH says each is studied for, one head-to-head trial, and the different cautions, including the turmeric…
Echinacea and elderberry are both used for colds, but they are different plants with different evidence and different cautions. What NIH says about each, and no winner.
Chamomile, valerian and lemon balm are used for relaxation and sleep. What NIH and the EU herbal committee say about each, the cautions that differ, and why there is no …
Peppermint is a natural cross of water mint and spearmint. What NIH and the EU herbal committee say about peppermint, the thin human research on spearmint, and safety po…
Ginkgo, Asian ginseng and bacopa are all sold for memory. Here is what trials and reviews found for each, where they differ, and the safety points to know.
What trials and health bodies say about St. John's wort compared with prescription antidepressants, and why combining them can be dangerous. Information only.
Ceylon and cassia cinnamon come from different trees. How they differ in coumarin, liver cautions and labeling, and what the research does and does not show.
Milk thistle and N-acetylcysteine (NAC) are both sold for liver health. What reviews found for each, how they differ, and why neither replaces medical care.
Does an herb work the same as a tea, a capsule or a tincture? What the sources say about why form matters, with green tea, ginkgo and milk thistle as examples.
Brewed green tea, matcha powder and green tea extract capsules differ in concentration and in liver safety. What NCCIH, LiverTox and reviews say about each.
When a study says a herb helped, which form did it test: fresh plant, dried herb, tea or extract? How regulators define each, examples from sage, black cohosh and passio…
Black cohosh, red clover and sage are studied for menopause hot flashes. Compare what reviews and regulators found, the liver warning for black cohosh, and who should as…
Compare lavender, lemon balm and passionflower for anxiety and sleep: what reviews and EU monographs say, how the forms differ, and safety with sedatives, surgery and pr…
How a plant, a herbal supplement and a prescription drug made from a plant differ in the sources: definitions, who checks safety and proof, examples such as willow and q…
Plain-language glossary of herbal medicine terms: plant names, teas, tinctures and extracts, regulator labels, research words and safety words, each tied to a source we …
One table of every single-herb profile in this library: scientific name, the first use studied and its evidence label, and the main caution, with a link to each full pro…
Answers to common questions about herbs and botanicals: whether they work, whether supplements are safe, natural versus synthetic, regulation, medicines, pregnancy and l…
Quick reference for herb emergencies: when to call 911, the US Poison Help number, warning signs for allergy, poisoning, liver and serotonin problems, and who to tell.
A plain-language profile of the peyote cactus (Lophophora williamsii): its name, mescaline content, Native American Church context, conservation concerns, risks and US l…
A plain-language profile of the San Pedro cactus (Echinopsis pachanoi, Trichocereus pachanoi): naming confusion, mescaline content, Andean traditions, risks and what we …
Which other cacti sources report as containing mescaline, why their names are confusing, how false peyote differs, and what is and is not known about risks and law.
A plain-language profile of chacruna (Psychotria viridis): its role as the DMT-containing leaf in ayahuasca, why the brew differs from DMT alone, risks and legal context.
Chaliponga (Diplopterys cabrerana) is a South American plant used as a DMT source in some ayahuasca preparations. This profile covers naming, safety, legal context and e…
Banisteriopsis caapi, the Amazonian vine called the ayahuasca vine: harmala alkaloids, MAO inhibition, variability, early research, and serious medicine-interaction risk…
Iboga (Tabernanthe iboga), a Central African shrub central to Bwiti tradition: botany, ibogaine relationship, conservation concerns, research limits and the serious card…
Salvia divinorum, a sage from a small region of Mexico traditionally used by the Mazatec people: salvinorin A, what research shows, documented risks, and legal context.
Yopo, ololiuqui, morning glory and Hawaiian baby woodrose seeds, and Mimosa tenuiflora: accepted names, what the sources show, documented harms and where evidence is thi…
Each of these has its own departments. Herbs that belong there are not duplicated here: this page links to them instead.
These herbs have the most human research summarized in our guides (counted from the evidence ratings on each profile). More research does not mean the herb works or is safe for you: open the guide to see what was found, including negative and mixed results.
Every published herb guide (414), with its scientific name, other common names and the plant part used. Each name opens one guide that brings together identity, traditional use, research, safety, forms and sources.
Published herb guides
414 herbs
Written and sourced one herb at a time. Each guide separates traditional use from research, rates the evidence for each outcome, lists documented risks and medicine interactions, and describes the forms that are sold. Start here.
Research Library database records
6,826 records
A reference database of traditional and botanical herb records with linked studies, many of them from Chinese-medicine and plant databases. A record gives names, properties and links. It is not a reviewed guide and does not rate evidence or safety. 48 records share a name with a published guide.
Search by herb, benefit, body system, goal, symptom or lab test. Each result explains why it matches and how strong the evidence is.
Filters: use, evidence, body system, body part, goal, root cause, habit, biomarker, condition
Pick a way to look, then pick a choice. Every list links to the full guide.
Pick the part of the plant that is used. Roots, leaves, flowers, seeds and bark are often used differently and carry different cautions. A herb can appear under more than one part.
Herbs whose guide mentions use in a traditional system. A mention shows history, not proof that it works.
The ways each herb is used, from its guide: tea, tincture, capsule, powder, extract, topical or the whole herb.
Herbs whose guide documents a point to check for this concern. Being listed does not mean the herb is unsafe for everyone. Open the guide to read the details.
The best level of evidence in each herb guide for any listed benefit. A stronger label for one use says nothing about its other uses or its safety.
Herbs have been used for health in many cultures for centuries. A traditional use tells you what people have done, not that it works. Here every herb is listed under the goals, body systems and actions its guide connects it to, and each link carries the strength of the evidence behind it.
Strongest
32 herbs
Clinical trials support a benefit
Promising
282 herbs
Early or mixed human evidence
Early science
89 herbs
Lab or animal research only
Unknown
11 herbs
Too little evidence to say
Each herb is counted once, at the strongest level its guide documents for any use. A strong label for one use says nothing about its other uses or its safety. "Traditional use" alone is not one of these labels: where a guide only reports history, the link is rated "Too little evidence to say". Read Traditional use vs research evidence.
Each card shows how many herbs are linked to a goal and how strong the evidence is. Green means clinical trials support a benefit; grey means too little evidence. These are links the guides document, not recommendations. For the wider picture, see the Wellness Goals section.
45 promising2 early science
Best-studied
Early or mixed human evidence (45)
Lab or animal research only (2)
Goal pages: Blood Sugar Balance · Metabolic Health · Weight Management
8 strongest25 promising2 early science
Best-studied
Clinical trials support a benefit (8)
Early or mixed human evidence (25)
Lab or animal research only (2)
Goal pages: Digestive Support · Gut Health
3 strongest29 promising
Best-studied
Clinical trials support a benefit (3)
Early or mixed human evidence (29)
Goal pages: Healthy Circulation · Heart Health · Blood Pressure Support · Cholesterol Balance
1 strongest25 promising3 early science
Best-studied
Clinical trials support a benefit (1)
Early or mixed human evidence (25)
Lab or animal research only (3)
Goal pages: Stress Reduction · Anxiety Support · Calm & Relaxation · Mood Balance
1 strongest27 promising
Best-studied
Clinical trials support a benefit (1)
Early or mixed human evidence (27)
Goal pages: Women’s Wellness · Menopause Support · Men’s Vitality · Libido Support · Fertility Support · Hormone Balance
14 promising2 early science
Best-studied
Early or mixed human evidence (14)
Lab or animal research only (2)
Goal pages: Better Sleep · Sleep Quality
14 promising1 early science
Best-studied
Early or mixed human evidence (14)
Lab or animal research only (1)
Goal pages: Joint Support · Mobility Support
14 promising
Best-studied
Early or mixed human evidence (14)
Goal pages: Immune Support · Seasonal Wellness
11 promising1 early science
Best-studied
Early or mixed human evidence (11)
Lab or animal research only (1)
Goal pages: Breathing Support · Lung Support
9 promising2 early science
Best-studied
Early or mixed human evidence (9)
Lab or animal research only (2)
Goal pages: Memory Support · Cognitive Performance · Brain Health · Better Focus · Mental Clarity
9 promising
Best-studied
Early or mixed human evidence (9)
Goal pages: Healthy Skin
7 promising1 early science
Best-studied
Early or mixed human evidence (7)
Lab or animal research only (1)
Goal pages: Liver Support · Bone Health
6 promising
Best-studied
Early or mixed human evidence (6)
Goal pages: Energy Boost · Reduce Fatigue · Physical Stamina · Endurance Support
The same links, organized the way anatomy and physiology textbooks do. "Action" describes what a herb is said to do (for example calming or digestive support); it names the claim, not the proof.
Clinical trials support a benefit (8)
Early or mixed human evidence (29)
Lab or animal research only (3)
Early or mixed human evidence (31)
Lab or animal research only (1)
Clinical trials support a benefit (1)
Early or mixed human evidence (23)
Lab or animal research only (2)
Clinical trials support a benefit (2)
Early or mixed human evidence (20)
Clinical trials support a benefit (2)
Early or mixed human evidence (19)
Clinical trials support a benefit (1)
Early or mixed human evidence (17)
Lab or animal research only (2)
Clinical trials support a benefit (1)
Early or mixed human evidence (16)
Lab or animal research only (2)
Early or mixed human evidence (18)
Early or mixed human evidence (15)
Lab or animal research only (2)
Early or mixed human evidence (17)
Early or mixed human evidence (13)
Lab or animal research only (4)
Early or mixed human evidence (13)
Lab or animal research only (4)
Clinical trials support a benefit (1)
Early or mixed human evidence (12)
Lab or animal research only (2)
Early or mixed human evidence (12)
Lab or animal research only (2)
Clinical trials support a benefit (1)
Early or mixed human evidence (10)
Lab or animal research only (2)
Early or mixed human evidence (10)
Lab or animal research only (3)
Early or mixed human evidence (12)
Early or mixed human evidence (12)
Early or mixed human evidence (9)
Lab or animal research only (2)
Clinical trials support a benefit (1)
Early or mixed human evidence (7)
Early or mixed human evidence (6)
Clinical trials support a benefit (8)
Early or mixed human evidence (11)
Lab or animal research only (2)
Early or mixed human evidence (18)
Lab or animal research only (2)
Clinical trials support a benefit (1)
Early or mixed human evidence (9)
Lab or animal research only (7)
Early or mixed human evidence (12)
Lab or animal research only (5)
Early or mixed human evidence (13)
Lab or animal research only (1)
Early or mixed human evidence (11)
Lab or animal research only (2)
Early or mixed human evidence (9)
Lab or animal research only (2)
Clinical trials support a benefit (1)
Early or mixed human evidence (7)
Lab or animal research only (3)
Clinical trials support a benefit (1)
Early or mixed human evidence (6)
Lab or animal research only (1)
Early or mixed human evidence (4)
Early or mixed human evidence (4)
Early or mixed human evidence (4)
Clinical trials support a benefit (8)
Early or mixed human evidence (25)
Lab or animal research only (2)
Early or mixed human evidence (32)
Lab or animal research only (1)
Early or mixed human evidence (3)
Lab or animal research only (26)
Early or mixed human evidence (2)
Lab or animal research only (25)
Clinical trials support a benefit (2)
Early or mixed human evidence (16)
Lab or animal research only (1)
Clinical trials support a benefit (1)
Early or mixed human evidence (16)
Lab or animal research only (2)
Early or mixed human evidence (7)
Lab or animal research only (7)
Early or mixed human evidence (10)
Lab or animal research only (4)
Clinical trials support a benefit (1)
Early or mixed human evidence (9)
Lab or animal research only (2)
Early or mixed human evidence (10)
Early or mixed human evidence (10)
Lab or animal research only (7)
Early or mixed human evidence (5)
Early or mixed human evidence (4)
Early or mixed human evidence (4)
Side-by-side guides for herbs that people confuse or choose between. They explain differences; they do not rank the herbs.
Each guide below looks at one concern, from sleep to skin, and separates herbs that were tested in people from herbs that are only traditional or lab-tested.
People have used herbs for health for many centuries. A traditional use tells you what people have done, not that it works. For what research found, see the Health Benefits and Scientific Evidence tabs.
Ayurveda, Traditional Chinese Medicine and other traditions each use plants in their own systems. The herbs below are the ones whose guide mentions the tradition in its own text. That a tradition uses a herb is history, not clinical evidence. Each guide says separately what trials found.
Read more: Therapies & Traditions · Ayurvedic and Chinese Herbs: Where They Are Covered on This Site · European Herbal Tradition, Pharmacopoeias and Monographs · African Herbal Medicine: Plants, Traditions and Conservation · North American Herbs and Indigenous Plant Knowledge · Latin American and Caribbean Herbs: Plants, Traditions and Cautions · A Short History of Herbal Medicine · Ethnobotany: How Traditional Uses Are Recorded and Studied.
Herbs are active substances. Some interact with prescription medicines, some are unsafe in pregnancy or with certain conditions, and some have been linked to serious harm. This tab brings together what the individual herb guides document, plus the general rules. Medicine interactions have their own tab.
Have the product bottle with you when you call. Poisoning: What to Do First · Poison Help by Country · Emergency Quick Reference: Whom to Call (911, 988, Poison Help) · Herb Safety Quick Reference: Emergency Signs and Whom to Call
Natural Remedy Safety: the full department · Herb Safety Quick Reference by Group of Medicines and Conditions
Each line comes from a herb's own guide, where it is backed by cited sources: 1,710 documented risks across 406 of the 414 herbs. A herb missing from a list is not proven safe: it may simply not have been studied. Open the herb's guide for the full wording and sources.
| Herb | What its guide documents |
|---|---|
| African wormwood | Liver-cell effects in the lab. In a 2025 test on human liver cells the water extract affected the cells at lower levels than sweet wormwood did. |
| Alisma (ze xie) | Possible liver effects at high amounts. Cell studies showed harm to liver cells at high concentrations; older records mention liver function impairment with large or lon… |
| Aloe vera | Liver injury (oral leaf extracts). Oral aloe leaf extracts have been linked to cases of acute hepatitis, after as little as 3 weeks to as long as 5 years of use. |
| Angelica pubescens (du huo) | Liver changes in animals. In animals, a 90-day study in rats and dogs found reversible liver changes at higher amounts, and isolated xanthotoxin caused liv… |
| Apricot kernel (bitter) | Nerve and liver harm. NCI lists liver damage and nerve damage affecting walking among effects of laetrile. The FDA says long-term intake may damage ner… |
| Artichoke leaf | Bile duct, gallstone and liver disease contraindication. The EU monograph lists bile-duct obstruction, cholangitis, liver disease, gallstones and other biliary disorders as contraindicat… |
| Asafoetida (hing) | Lack of safety data (pregnancy, medicines, liver, kidney). We found no source we could read that covers pregnancy, breastfeeding, medicine interactions or liver and kidney safety. Absence … |
| Ashitaba | Liver and blood-fat changes at high doses. In rats, higher doses raised cholesterol, triglycerides and the liver enzyme ALP, and liver cell vacuolation appeared from 100 mg… |
| Ashwagandha | Liver injury (documented risk). Rare cases of liver injury are reported, with jaundice, itching and nausea after 2 to 12 weeks. Most recovered after stopping; pe… |
| Asian ginseng | Liver damage, allergy and autoimmune conditions. NCCIH lists severe rash, liver damage and severe allergic reactions as uncommon, and says it may worsen autoimmune disorders. MSK… |
| Autumn crocus (colchicum) | Higher risk with kidney or liver impairment and age. Older adults and people with kidney or liver impairment are at higher risk of colchicine toxicity. |
| Bael | Supplement liver-injury cluster (ingredient not named). In 2013 a multi-ingredient weight-loss supplement was tied to serious hepatitis in Hawaii (29 confirmed cases, one death, two tra… |
| Baikal skullcap | Liver injury reports. Baikal skullcap root has been linked to drug-induced liver injury in case reports and in one large hospital study, where about 1 … |
| Baikal skullcap | Higher liver risk at larger amounts and with a gene variant. In a Shanghai hospital study, the risk of liver injury was higher when the daily amount was above the pharmacopoeia range, and a … |
| Bakuchi (babchi) | Liver injury case reports. Doctors have published case reports of liver injury, including acute-on-chronic liver failure, bile-duct loss and cirrhosis, afte… |
| Barberry | Medicine interactions through liver enzymes. Barberry and its berberine affect several enzymes that process medicines, especially CYP2D6 and CYP3A4, so some medicines could a… |
| Bayberry (wax myrtle) | Nausea, vomiting and liver damage when swallowed. Two consumer drug references rate bayberry by mouth as possibly unsafe, with nausea, vomiting and liver damage listed as possible… |
| Berberine | Liver and kidney toxicity at some doses. A 2026 toxicology review of Berberis plants and their alkaloids reports multi-system toxicity (liver, kidney, heart, immune syste… |
| Bibhitaki | Medicine interactions through liver enzymes (as part of triphala). MSK says triphala blocks the liver enzymes CYP3A4 and CYP2D6 and may raise levels of medicines those enzymes clear. |
| Bitter leaf | Fatal liver and kidney failure case after use to end a pregnancy. A case series from northern Uganda describes a woman who used bitter leaf to induce an abortion and died of liver and kidney fail… |
| Black cohosh | Liver injury (rare reports). Serious liver damage has been reported in some people taking black cohosh products. It is rare and it is unclear whether the herb… |
| Black seed | Medicine interactions (liver enzymes, warfarin). Black seed may inhibit the liver enzymes CYP2D6 and CYP3A4 and change levels of medicines cleared by them. Thymoquinone inhibited… |
| Black seed | Liver and kidney effects at high doses. High doses caused liver and kidney damage in rats. Human data are lacking; a 12-week animal study of the oil showed no liver enzy… |
| Blue vervain | Unknown safety in children and in liver or kidney disease. The reference article says safety in young children and in people with severe liver or kidney disease is unknown. |
| Boldo | Liver injury case reports. Two published case reports describe jaundice and raised liver tests in older people after repeated boldo leaf tea; both recovered… |
| Boldo | Bile duct, gallstone and liver disease contraindication. The EU says boldo leaf must not be used with bile-duct obstruction, cholangitis, liver disease, gallstones or other bile-duct dis… |
| Boneset | Pyrrolizidine alkaloids and possible liver harm. All 49 boneset samples tested contained dehydropyrrolizidine alkaloids, a compound family linked to human liver disease. Tincture… |
| Boneset | Existing liver disease. People with liver disease could get worse, according to a consumer drug reference. |
| Borage | Liver damage from pyrrolizidine alkaloids. Borage leaf and flower contain small amounts of pyrrolizidine alkaloids (PAs) that can injure the liver. The EU herbal committee … |
| Buchu | Liver toxicity of pulegone. High doses of buchu essential oil harmed the liver in rats, which the review ties to pulegone. EBSCO calls pulegone a known liver… |
| Buchu | Pregnancy, breastfeeding, children, liver and kidney disease. EBSCO says young children, pregnant or nursing women, and people with liver or kidney disease should not use buchu. |
| Bupleurum | Liver injury (hepatotoxicity). MSK says case reports link bupleurum to liver damage, with saikosaponins suspected of dose-related injury. A 2017 review describe… |
| Bupleurum | Medicine interactions (liver enzymes). Lab tests suggest bupleurum may affect drugs cleared by CYP2C9, and animal studies suggest it may switch on CYP2E1, 2D6 and 3A4. … |
| Butterbur | Safety: rare liver injury even with PA-free products. Rare cases of liver injury have been reported with products claimed to be PA-free, so PA-free labelling does not remove all risk. |
| Capillary wormwood (yin chen hao) | Liver injury case reports. A compilation of Chinese-herb liver-injury cases lists Yin Chen Hao among 28 of 57 herbs or mixtures with established causality: … |
| Cassia seed (jue ming zi) | Liver injury concern. Rat studies reported liver injury from cassia seed extracts and from its anthraquinone aurantio-obtusin, and a published case ana… |
| Chamomile | Interactions with warfarin and liver-processed medicines. Interactions have been reported with warfarin and some medicines processed by the liver; an interaction with sedatives is theoret… |
| Chaparral (creosote bush) | Liver injury (hepatotoxicity). Reviews of reported cases link chaparral products to serious liver injury, including cirrhosis and liver failure needing a transp… |
| Chaparral (creosote bush) | Liver cleansing claims. Chaparral is sold as a liver cleanser, yet the sources describe liver harm, not benefit. |
| Chinese asparagus root (tian men dong) | Possible interaction with medicines (liver enzymes). In animal studies the herb switched on the liver enzymes CYP2E1 and CYP1A2, which clear many medicines. Memorial Sloan Kettering … |
| Chitrak (Ceylon leadwort) | Liver and kidney effects in animals. In repeated-dose rat studies the liver and kidney were the main organs affected; a petroleum-ether root extract was about ten tim… |
| Cinnamon | Coumarin and the liver (cassia). Cassia cinnamon contains coumarin, and effects on the liver have been reported. Usual food amounts rarely contain enough to matte… |
| Cinnamon twig (gui zhi) | Liver and coumarin caution. Cassia cinnamon contains coumarin; liver interactions have been reported, and some cassia products have high levels. Twig-specifi… |
| Cinnamon twig (gui zhi) | Cinnamon with statins and liver-enzyme medicines. MSK reports hepatitis when cinnamon was taken with statins, and lab findings that cinnamon may raise side effects of some medicin… |
| Coltsfoot | Liver injury from pyrrolizidine alkaloids. Coltsfoot can contain pyrrolizidine alkaloids. The EU herbal committee describes toxic PAs as damaging the liver, causing blocked… |
| Coltsfoot | Liver cancer in animals. Rats fed young coltsfoot flowers for up to 600 days developed liver tumors at the higher diets (8 of 12 on the highest diet, none… |
| Coltsfoot | Infant liver vein disease after a herbal tea. An 18-month-old developed veno-occlusive disease after a tea thought to contain coltsfoot; analysis suggested a look-alike plant … |
| Comfrey | Liver toxicity when taken by mouth. Comfrey contains pyrrolizidine alkaloids that are toxic to the liver. Case reports describe liver veno-occlusive disease after or… |
| Coptis (goldthread) | Pregnancy, breastfeeding and newborn jaundice. Memorial Sloan Kettering advises avoiding berberine in pregnancy and breastfeeding because it may worsen jaundice in infants or c… |
| Corydalis | Liver injury. Two adults developed probable drug-induced liver injury after using a corydalis-containing sleep supplement; both improved after … |
| Couch grass | Documented risk: unconfirmed liver reports in mixtures. Two old French reports to the WHO database described severe liver problems (one fatal) in women taking mixtures containing couch … |
| Cuscuta seed (tu si zi) | Immune-suppressing and liver-enzyme-processed medicines (possible). The review says a seed compound (kaempferol) may counteract immunosuppressants and that flavonoids may alter cytochrome P450 or c… |
| Damiana | Possible medicine interactions (liver enzymes). A damiana leaf extract strongly blocked the liver enzymes CYP3A4 and CYP1A2 in laboratory tests, which hints at possible medicine… |
| Damiana | Safety data gaps (pregnancy, children, surgery, liver). The sources read give no information on pregnancy, breastfeeding, children, surgery or liver effects in people. Animal toxicity s… |
| Dandelion | Liver, bile duct and gallbladder disease. Bile duct blockage, cholangitis, liver disease, gallstones and other biliary disease are listed reasons not to use dandelion root… |
| Dragon's blood (sangre de grado) | Side effects and liver enzyme changes seen with the drug. In three placebo-controlled trials (696 people), reactions included respiratory infections, cough, gas, nausea, raised bilirubin … |
| Echinacea | Common side effects and rare liver reports. NCCIH lists digestive symptoms such as abdominal pain and nausea. The site page, citing NIH LiverTox, reports isolated cases of l… |
| Epazote | Liver and kidney harm. TRAMIL contraindicates oral use in liver disease and kidney failure and lists liver and kidney damage among toxic effects of the … |
| Eucalyptus | Effects on drug-processing liver enzymes. Lab and animal studies, and a small 1970 human study of 5 volunteers, suggest cineole can speed up liver enzymes that break down … |
| Eucalyptus | Digestive upset, liver and gall bladder cautions. Cineole capsules caused heartburn, nausea or diarrhea in a few trial participants. The German Commission E, cited by the EMA, lis… |
| Evodia (wu zhu yu) | Liver toxicity risk. A 2025 review calls the fruit mildly toxic and says it has obvious toxic effects on the human liver; animal and cell studies show… |
| False unicorn root | Possible effect on drug-processing liver enzymes (laboratory). In a 2011 test-tube study, four commercial women's herbal products including false unicorn each slowed some drug-processing enzym… |
| Fumitory | Caution with bile-duct and liver disease. The EU monograph advises against fumitory with bile duct obstruction, cholangitis, liver disease or gallstones, because the herb … |
| Fumitory | Case report of acute hepatitis with a fumitory-containing combination. One published case of acute hepatitis was judged probably caused by a multi-herb product that included fumitory; the herb cannot … |
| Garcinia cambogia | Liver injury reports. NCCIH says there are numerous reports of liver toxicity, some severe, though it appears uncommon. A 2025 review counted more than… |
| Gardenia fruit (zhi zi) | Liver injury risk (documented in animals). High doses of geniposide, the main compound in gardenia fruit, injured the liver in rats, with raised liver enzymes and changed b… |
| Gardenia fruit (zhi zi) | Possible effect on liver enzymes (CYP450). A review proposes that genipin, formed from geniposide, can bind proteins and inactivate liver CYP450 enzymes in animals, which c… |
| Goat's rue | Liver enzyme changes in case reports. LactMed describes mildly raised liver enzymes that eased after goat's rue and torbangun were stopped, and an enlarged liver with … |
| Gotu kola | Liver injury (documented risk). Case reports describe jaundice and hepatitis in three adult women after 20 to 60 days of gotu kola, and a separate letter reports… |
| Gravel root (Joe-Pye weed) | Possible liver injury from pyrrolizidine alkaloids. Gravel root belongs to a plant group whose members contain liver-toxic pyrrolizidine alkaloids. A consumer drug reference warns o… |
| Gravel root (Joe-Pye weed) | Interaction with liver-enzyme inducing medicines. RxList rates a moderate interaction with carbamazepine, phenobarbital, phenytoin, rifampin and rifabutin, which may speed breakdo… |
| Graviola (soursop) | Liver and kidney toxicity (animal reports). Cancer Research UK says frequent use may damage the kidneys and liver, and a graviola acetogenin caused liver and kidney toxicity… |
| Greater celandine | Liver injury risk. Greater celandine taken by mouth has been linked to liver inflammation and jaundice in many case reports. Most reports are from E… |
| Greater celandine | Medicines that can harm the liver. German rules, described by EMA, say products containing greater celandine are contraindicated with other liver-damaging medicines… |
| Ground ivy | Kidney and liver cautions. A consumer drug reference advises against use with kidney or liver disease because the plant may irritate the kidneys and harm th… |
| Guduchi (giloy) | Liver injury reports (herb-induced liver injury). Several reports describe liver injury with guduchi, from acute hepatitis to liver failure. A study of 43 patients in India judged… |
| Guduchi (giloy) | Can unmask autoimmune hepatitis. The Indian study found guduchi linked to hepatitis with autoimmune features, and it could bring out autoimmune hepatitis in peopl… |
| Gymnema | Liver injury (case report). A case of toxic hepatitis was reported with a gymnema tea. EFSA said causality is unclear and contamination or adulteration could… |
| Haritaki | Possible effects on liver enzymes and medicine levels. In rats a fruit compound switched on several liver enzymes that break down medicines; MSK advises against triphala with medicines… |
| He shou wu | Liver injury (documented risk). Reports and case series link he shou wu to liver-cell damage, with tiredness, poor appetite and yellowing of the skin or eyes. In… |
| Hibiscus | Liver enzyme (AST) and long-term safety. The 2025 review saw a small, clinically insignificant rise in one liver enzyme (AST) with no higher risk of adverse events, but s… |
| Horny goat weed | Liver injury. Two Chinese products with Epimedium leaf as the main ingredient have been linked to liver injury in people. A rat study found an … |
| Horsetail | Reports of liver injury. The EMA report describes a man with chronic hepatitis B who developed severe hepatitis after two weeks of drinking horsetail juic… |
| Hyssop | Pregnancy, children, liver, kidney, medicines and surgery. The sources read give no information on these; the 1999 report included a child who had seizures after essential oils and recover… |
| Imperata (bai mao gen) | Liver changes with a long-term methanol extract (rats). In rats a water extract was safe for 90 days at the doses tested, while a methanol extract at a high dose caused mild liver chang… |
| Japanese knotweed (hu zhang) | Risk: emodin and the liver, kidney and reproduction. Emodin, an anthraquinone in the root, could harm the liver, kidney and reproduction at high doses and with long-term use. |
| Java tea (cat's whiskers) | Liver injury (one doubtful case report). One 2004 case report described hepatitis in a woman who took green tea capsules and Orthosiphon capsules together; she recovered … |
| Kava | Liver injury risk. Kava products have been linked to rare cases of liver injury, some serious or fatal, including liver failure needing a transplant… |
| Khat | Chronic liver disease. An Ethiopian hospital study found a dose-related link between khat chewing and chronic liver disease in men after adjusting for a… |
| Kokum | Liver injury caution (HCA shared with Garcinia cambogia). NCCIH reports numerous cases of liver toxicity, some severe though uncommon, with Garcinia cambogia products. The kokum review sa… |
| Kratom | Liver injury. A 2026 systematic review found 32 published cases of kratom-associated liver injury, mostly bile-flow (cholestatic), usually impr… |
| Kudzu | Interaction with diabetes medicines and liver enzymes. MSK says animal data suggest kudzu may increase the effect of antidiabetic drugs and lab data show puerarin affects CYP2D6 and CY… |
| Kudzu | Liver and kidney case reports. MSK describes short-term liver and blood test changes in a small study of postmenopausal women, one case of kidney inflammation a… |
| Kutaja (kurchi) | Liver and animal toxicity signals. The 2020 review describes liver damage in rats given an ethanol extract for three months at 10 to 20 times the human dose, and 30… |
| Lemon balm | Liver safety record. NIH LiverTox says lemon balm extracts are generally recognized as safe and have not been linked to liver enzyme rises or clinical… |
| Lion's tail (wild dagga) | Possible liver and kidney effects (animal data). A 21-day rat study found changes in liver, kidney, blood and fat measures, and concluded the extract may not be safe as an oral r… |
| Lungwort | Possible liver-toxic pyrrolizidine alkaloids. Lungwort is in the borage family, where PAs occur. A study of the related P. obscura found lycopsamine-type PAs mostly in roots a… |
| Maca | Liver safety. NIH LiverTox says maca has not been implicated in liver injury. This is a statement about reports to date, not a guarantee for ev… |
| Mallow (common mallow) | Reports of liver and kidney injury after eating mallow. The EU assessment cites two published cases of acute liver and kidney damage after eating mallow as a meal or juice; liver tests … |
| Manjistha | Liver effects in animals (fruit extract). A crude alcohol extract of the fruit caused harmful liver effects in animals. The review says the studies were short. |
| Morinda root (ba ji tian) | Side effects at high amounts and unknown liver or laxative effects. The 2018 review reports no significant adverse effects at normal clinical doses, but large lab amounts may cause irritability and… |
| Neem | Possible medicine interactions (liver enzymes). In laboratory work, a neem extract inhibited the liver enzymes CYP3A4/5, CYP2C8 and CYP2C9. MSK says the clinical relevance is un… |
| Noni | Liver injury reports. Cases of liver damage have been reported in people who drank noni juice or tea for several weeks. Whether noni caused them is unc… |
| Papaya leaf | Liver enzymes and liver impairment. Animal studies showed raised liver enzymes with repeated dosing; two unpublished human reports described raised transaminases rat… |
| Passionflower | Liver safety. NIH LiverTox says passionflower has not been implicated in raised liver enzymes or clinically apparent liver injury. |
| Pau d'arco | Liver failure report. PeaceHealth describes a death from liver failure in a man who took pau d'arco with skullcap and zinc; skullcap contaminated with … |
| Pelargonium (Umckaloabo) | Possible liver problems. Liver problems have been reported with pelargonium root medicines. How often is not known, and whether the plant caused them is d… |
| Pennyroyal | Liver injury and liver failure. Swallowed pennyroyal oil or tea has caused severe liver injury, liver failure and death. LiverTox calls the oil highly toxic when… |
| Peppermint | Gallbladder, bile-duct and liver cautions for the oil (documented risk). The EU oil monograph lists liver disease, inflamed bile ducts, gallstones and other bile-duct disorders as reasons not to use pep… |
| Phellodendron | Newborn jaundice and kernicterus concern (berberine). A review names neonatal jaundice and kernicterus as the main safety concern of the bark's berberine. Regulators and Memorial Sloa… |
| Phellodendron | Medicine interactions (transplant drugs, liver enzymes, diabetes drugs). For berberine, Memorial Sloan Kettering reports raised cyclosporine levels in kidney-transplant adults, a tacrolimus case in a ch… |
| Pueraria mirifica (kwao krua) | Rat toxicity: estrogen-like effects and mild liver change. In rats, 28-day oral exposure caused estrogen-like effects on ovary, uterus and breast tissue and mild fat change in liver cells … |
| Red clover | Effects on drug-clearing liver enzymes and methotrexate. Preclinical studies suggest inhibition of several CYP450 enzymes (clinical relevance not determined). One case report links use w… |
| Rhubarb root | Risk: possible liver toxicity (animal studies). Animal studies suggest possible liver toxicity at high amounts and with long-term use. |
| Rooibos | Liver injury case reports. MSK describes case reports of raised liver enzymes, liver injury with jaundice and, with very large daily intake, liver toxicity … |
| Rooibos | Possible reproductive, liver and kidney effects (rat studies). MSK cites rat studies suggesting long-term exposure may affect reproduction, fertility, and liver and kidney function. No human s… |
| Rosemary | Liver and bile duct conditions need supervision. Bile duct obstruction, cholangitis, liver disease, gallstones and other biliary disorders need medical supervision before oral us… |
| Rue | Poisoning when swallowed (liver, kidney, brain, blood). The Hong Kong poisonous plant atlas lists vomiting, abdominal pain, dizziness, convulsions, liver and kidney impairment, and in s… |
| Sandalwood | Internal use: pregnancy, children, kidney and liver disease. Consumer references advise against internal use in pregnancy, breastfeeding, infants and children, and in people with kidney dise… |
| Saptaparna (devil's tree) | Liver and blood changes in animals given bark extract. In a 28-day rat study, higher doses of a methanolic bark extract caused liver damage signs, raised liver enzymes, lower blood cou… |
| Sariva (Indian sarsaparilla) | Animal toxicity and liver changes. A root extract study reported nonspecific liver changes in animals; the abstract gives no detail. A mouse study reported low toxi… |
| Sassafras | Liver cancer risk from safrole. Safrole, the main oil of sassafras, caused liver tumors in rats and mice. The US National Toxicology Program lists it as reasonab… |
| Sassafras | Possible interference with liver enzymes. In laboratory tests safrole blocked the liver enzymes CYP1A2, CYP2A6 and CYP2E1. MSK does not describe an effect in people. |
| Saw palmetto | Liver injury and pancreatitis. Single case reports describe severe liver damage and acute pancreatitis. |
| Schisandra | Medicine interactions via liver enzymes and P-glycoprotein. Lab and animal studies suggest schisandra can affect medicines broken down by CYP1A2, CYP3A4 or CYP3A5 and may raise side effects… |
| Schisandra | Effect on liver blood tests. MSK says schisandra can lower the liver enzymes ALT and AST on lab tests, which could change how liver tests are read. It did not… |
| Senna | Liver injury at high doses over long periods. NIH LiverTox (as reported on the site page) says senna is usually well tolerated but can cause clinically apparent liver injury a… |
| Skullcap | Liver injury reports. Skullcap has been linked to several cases of clinically apparent liver injury, usually when taken with other herbs. This is the m… |
| Sophora flavescens (ku shen) | Possible liver harm from matrine. Matrine harmed the liver in mice and in human liver cells in the laboratory. Whether this happens with normal human use is unclea… |
| Spirulina | Liver injury (rare). LiverTox says liver injury from spirulina itself must be very rare, with case reports confounded by other ingredients. |
| Stinging nettle | Possible interaction with diuretics, blood pressure medicines and liver-processed drugs. Based on animal studies, nettle may add to diuretics and blood pressure medicines and may inhibit CYP450 enzymes. Clinical releva… |
| Suma (Brazilian ginseng) | Safety not established (pregnancy, breastfeeding, children, severe liver or kidney disease). EBSCO says safety has not been established in pregnant or nursing women, young children, or people with severe liver or kidney di… |
| Sweet clover (melilot) | Liver injury linked to coumarin. Melilot contains coumarin, which damages the liver of rats and mice at high doses. In people, cases are mostly at higher daily am… |
| Sweet woodruff | Coumarin and the liver. AGES says large amounts of coumarin over a long period can affect the liver, and in sensitive people raise blood liver values up … |
| Sweet wormwood (Artemisia annua) | Liver injury (hepatitis). A 2019 case report links Artemisia annua tea used for malaria prevention to cholestatic hepatitis. Medsafe received 25 liver-harm… |
| Tagara (Indian valerian) | Rare liver injury reports (common valerian). NIH LiverTox links common valerian to rare, clinically apparent liver injury, and NIH says reports mostly involved other herbal p… |
| Tansy | Liver, kidney and bleeding harm. The thujone monograph lists liver inflammation and intestinal bleeding; the consumer reference adds kidney or liver damage. |
| Taxillus (sang ji sheng) | Liver and embryo toxicity, and liver or heart disease. A 2022 review says the plant shows liver toxicity and embryo toxicity and may cause complications in some people with liver or he… |
| Tepezcohuite | Possible liver and organ toxicity (animals). A 1991 rabbit study raised possible liver toxicity, and a 2024 mouse study of a root bark extract saw blood and organ tissue chan… |
| Thuja (northern white cedar) | Possible liver injury. One case report links thuja plus black cohosh to probable herb-induced liver injury that resolved after both were stopped. |
| Thunder god vine | Serious kidney and liver toxicity. NCCIH lists kidney damage and liver problems as serious risks and says rare deaths have been reported, possibly linked to certain… |
| Tribulus | Liver, kidney and nerve toxicity (case reports). Case reports describe severe liver and kidney injury and a seizure after tribulus products or herbal water. Case reports cannot s… |
| Turmeric | Liver injury risk. Liver damage has been reported with turmeric products, especially highly absorbable curcumin products. A US series of ten cases i… |
| Uncaria (gou teng) | Possible liver-enzyme drug interactions. A 2026 review says gou teng alkaloids may inhibit CYP3A4 and CYP2D6 and activate PXR, which could in theory alter levels of drugs… |
| Uncaria (gou teng) | Liver safety questions. The review flags possible liver injury at high doses or long use through CYP3A4 activation of hirsutine, and a computer-based stu… |
| Usnea (old man's beard lichen) | Severe liver injury with usnic acid weight-loss products. Usnic acid weight-loss supplements have been linked to acute hepatitis, liver failure, liver transplants and at least one death. … |
| Valerian | Rare liver injury. Liver injury has been reported in rare cases, most often when valerian was taken with other herbs. |
| Vidari kanda | Liver enzyme rise at higher amounts (animal). In a mouse study described in the review, higher amounts of tuber powder temporarily raised liver enzymes (AST, ALT), and the aut… |
| Vijaysar (Indian kino) | Pregnancy, breastfeeding, children, liver and kidney: not established. No human study in pregnancy, breastfeeding or children was found. A rat study of one related compound (3'-hydroxypterostilbene) f… |
| Watercress | Liver fluke infection from wild watercress. CDC names watercress as an example of an aquatic plant that can carry Fasciola larvae. Infection reaches the liver and bile ducts… |
| Willow bark | Risk: liver and kidney disease. EMA lists severe liver or kidney dysfunction, clotting disorders and G6PD deficiency as reasons not to use willow bark. Memorial … |
| Witch hazel | Swallowing: stomach upset and rare liver damage. The EMA advises caution with long-term oral use because of tannins: stomach irritation can occur and, in rare cases, liver damage. |
| Wormwood | Liver injury. The EU monograph lists liver and bile duct disease as reasons not to use wormwood. A 2025 case report describes two people with t… |
| Xanthium (cang er zi, cocklebur) | Liver injury from the fruit. The fruit contains carboxyatractyloside and atractyloside. In mice these caused extensive liver injury with raised liver enzymes,… |
| Herb | What its guide documents |
|---|---|
| Alisma (ze xie) | Kidney caution with long-term high amounts. A 2025 review says Alisma is generally safe at conventional amounts but advises that people with impaired kidney function be care… |
| Angelica pubescens (du huo) | Kidney toxicity in mice. A water extract caused kidney toxicity in mice, possibly by blocking transporters that clear waste from the blood. |
| Asafoetida (hing) | Lack of safety data (pregnancy, medicines, liver, kidney). We found no source we could read that covers pregnancy, breastfeeding, medicine interactions or liver and kidney safety. Absence … |
| Autumn crocus (colchicum) | Higher risk with kidney or liver impairment and age. Older adults and people with kidney or liver impairment are at higher risk of colchicine toxicity. |
| Berberine | Liver and kidney toxicity at some doses. A 2026 toxicology review of Berberis plants and their alkaloids reports multi-system toxicity (liver, kidney, heart, immune syste… |
| Birch leaf | Heart or kidney disease and fluid restriction. The EU monograph says birch leaf should not be used where less fluid intake is advised, for example severe heart or kidney diseas… |
| Bitter leaf | Fatal liver and kidney failure case after use to end a pregnancy. A case series from northern Uganda describes a woman who used bitter leaf to induce an abortion and died of liver and kidney fail… |
| Black haw | Kidney-stone caution (oxalic acid). The bark contains oxalic acid, which might add to stone formation in people with a history of kidney stones. |
| Black seed | Liver and kidney effects at high doses. High doses caused liver and kidney damage in rats. Human data are lacking; a 12-week animal study of the oil showed no liver enzy… |
| Bladderwrack | Kidney problems. The EU assessment reports kidney collecting-duct defects and a case of Fanconi syndrome after bladderwrack, and advises caution i… |
| Blue vervain | Unknown safety in children and in liver or kidney disease. The reference article says safety in young children and in people with severe liver or kidney disease is unknown. |
| Buchu | Pregnancy, breastfeeding, children, liver and kidney disease. EBSCO says young children, pregnant or nursing women, and people with liver or kidney disease should not use buchu. |
| Camu camu | Kidney stones (vitamin C in large amounts). MedlinePlus lists kidney stones as a rare effect of vitamin C above 2,000 mg a day. |
| Centaury | Kidney injury in a case report of a herb mixture. A 2024 case report describes severe kidney injury (interstitial nephritis) in a teenager who long took a mixture of centaury, wor… |
| Chaparral (creosote bush) | Kidney harm (reported). Memorial Sloan Kettering lists kidney failure and reports kidney cysts and kidney cancer in regular tea drinkers; a 1994 case rep… |
| Chitrak (Ceylon leadwort) | Liver and kidney effects in animals. In repeated-dose rat studies the liver and kidney were the main organs affected; a petroleum-ether root extract was about ten tim… |
| Cinchona bark | Kidney damage and low blood sugar. MedlinePlus lists kidney damage and low blood sugar as possible effects of quinine. |
| Coleus forskohlii (forskolin) | Polycystic kidney disease (documented caution). People with polycystic kidney disease are advised to avoid forskolin because it may contribute to cyst enlargement. |
| Common sorrel | High oxalate content: kidney stone and kidney disease caution. Sorrel-type plants are high in oxalate, which is the main material in most kidney stones. The NIDDK advises people who have had c… |
| Common sorrel | Oxalate kidney injury from leafy vegetables. A 2026 case report describes acute kidney failure with calcium oxalate crystals after one meal of fresh Swiss chard (not sorrel) … |
| Corn silk | Potassium loss and kidney filtering (rat findings). In rats, a water extract increased potassium excretion and lowered a measure of kidney filtering at a high dose. |
| Couch grass | Documented risk: people who must limit fluids, severe heart or kidney disease. Because the herb is meant to raise urine flow, the tea is not recommended where a doctor advises limiting fluids, and the EU safe… |
| Dandelion | Possible high potassium in kidney failure, diabetes or heart failure. The EU committee says people with kidney failure, diabetes or heart failure should avoid it because of possible high potassium (h… |
| Epazote | Liver and kidney harm. TRAMIL contraindicates oral use in liver disease and kidney failure and lists liver and kidney damage among toxic effects of the … |
| Evodia (wu zhu yu) | Kidney toxicity in animals. Evodiamine raised blood urea nitrogen and creatinine in mice; a rat study of a high-dose extract showed kidney changes. |
| Gardenia fruit (zhi zi) | Possible kidney effects at high doses (animals). A 2025 review says high doses or long dosing may affect liver and kidney function in rodents; the safety profile is described as … |
| Goldenrod | Fluid intake and heart or kidney disease. Not suitable where less fluid is advised, such as severe heart or kidney disease. Preparations need enough fluid intake. |
| Graviola (soursop) | Liver and kidney toxicity (animal reports). Cancer Research UK says frequent use may damage the kidneys and liver, and a graviola acetogenin caused liver and kidney toxicity… |
| Ground ivy | Kidney and liver cautions. A consumer drug reference advises against use with kidney or liver disease because the plant may irritate the kidneys and harm th… |
| Hoodia | Adrenal hormone enzyme inhibition (lab). MSK says lab studies found a hoodia compound inhibits several adrenal steroid-making enzymes; clinical meaning is not stated. |
| Horehound | Kidney injury (single case report). A 2024 case report attributed severe acute kidney injury in a 17-year-old to a mixture of three plants including white horehound.… |
| Horsetail | Fluid intake, heart and kidney disease. The EU monograph says horsetail for urinary use should not be used where reduced fluid intake is recommended, for example severe … |
| Houttuynia (yu xing cao) | Aristolactam alkaloids and kidney concern. The plant contains aristolactams, which are chemically related to kidney-damaging aristolochic acids. Two Chinese lab studies did… |
| Hyssop | Pregnancy, children, liver, kidney, medicines and surgery. The sources read give no information on these; the 1999 report included a child who had seizures after essential oils and recover… |
| Imperata (bai mao gen) | Potassium content and kidney or medicine caution. The review says high potassium content may contribute to the diuretic effect but gives no values. No source we read describes pot… |
| Irvingia (African mango seed) | Kidney failure case report. MSK describes one patient who became dialysis-dependent after about 2.5 months of an African mango herbal product. |
| Japanese knotweed (hu zhang) | Risk: emodin and the liver, kidney and reproduction. Emodin, an anthraquinone in the root, could harm the liver, kidney and reproduction at high doses and with long-term use. |
| Java tea (cat's whiskers) | Limit fluids: heart and kidney disease. The EU says not to use Java tea where reduced fluid intake is recommended, such as severe heart or kidney disease. Older German a… |
| Juniper Berry | Not recommended in severe kidney disease. Juniper berry is not recommended in severe kidney disease, including infectious interstitial nephritis, pyelitis and pyelonephrit… |
| Kudzu | Liver and kidney case reports. MSK describes short-term liver and blood test changes in a small study of postmenopausal women, one case of kidney inflammation a… |
| Lemongrass | Kidney function with daily tea (documented risk). In a 105-person trial, 30 days of daily lemongrass infusions was linked to lower creatinine clearance and eGFR, measures of kidne… |
| Lion's tail (wild dagga) | Possible liver and kidney effects (animal data). A 21-day rat study found changes in liver, kidney, blood and fat measures, and concluded the extract may not be safe as an oral r… |
| Lovage | Kidney inflammation and heart- or kidney-related swelling. An encyclopedia says lovage root flushing should not be used in acute inflammatory kidney disease or in heart- or kidney-related … |
| Magnolia bark | Kidney injury story: Aristolochia mix-up. Kidney failure cases in Belgium followed slimming capsules that contained magnolia bark and a kidney-toxic Aristolochia plant, an… |
| Mallow (common mallow) | Reports of liver and kidney injury after eating mallow. The EU assessment cites two published cases of acute liver and kidney damage after eating mallow as a meal or juice; liver tests … |
| Manjistha | Kidney and cancer-related findings for rubiadin and madder compounds. Rubiadin, an anthraquinone that the review lists for R. cordifolia, caused kidney tumours in rats; alizarin did so less strongly.… |
| Nasturtium (garden) | Stomach ulcer and kidney disease cautions. A herbal reference lists stomach or intestinal ulcers and kidney disease as reasons not to use the herb. |
| Pennyroyal | Kidney, brain and other organ effects. MSK lists liver and kidney toxicity, seizures, brain swelling, clotting problems and low blood sugar among published cases (at le… |
| Restharrow | Fluid-restriction conditions (heart or kidney disease, oedema). The EMA says restharrow root must not be used where reduced fluid intake is recommended, e.g. severe heart or kidney disease, and… |
| Rhubarb root | Risk: oxalate and kidney harm. Rhubarb is high in oxalates and may cause kidney problems; MSK cites case reports of kidney damage or failure after heavy intake … |
| Rooibos | Possible reproductive, liver and kidney effects (rat studies). MSK cites rat studies suggesting long-term exposure may affect reproduction, fertility, and liver and kidney function. No human s… |
| Rue | Poisoning when swallowed (liver, kidney, brain, blood). The Hong Kong poisonous plant atlas lists vomiting, abdominal pain, dizziness, convulsions, liver and kidney impairment, and in s… |
| Sandalwood | Internal use: pregnancy, children, kidney and liver disease. Consumer references advise against internal use in pregnancy, breastfeeding, infants and children, and in people with kidney dise… |
| Sarsaparilla | Kidney disease may worsen. RxList says sarsaparilla may worsen kidney disease and people with kidney problems should avoid it. |
| Scotch broom | Kidney disease and breastfeeding cautions. The reference says some chemicals in the plant might worsen kidney disease and rates oral use likely unsafe during breastfeeding. |
| Stephania (fang ji) | Mix-up with Aristolochia (aristolochic acid) causing kidney failure and urinary cancer. In Belgian slimming pills, Stephania tetrandra was inadvertently replaced by Aristolochia fangchi. Patients developed fast kidney… |
| Stephania (fang ji) | Aristolochic acid nephropathy has no effective treatment. A 2023 review says the kidney decline from aristolochic acid cannot be stopped or reversed by an effective treatment, and cases s… |
| Suma (Brazilian ginseng) | Safety not established (pregnancy, breastfeeding, children, severe liver or kidney disease). EBSCO says safety has not been established in pregnant or nursing women, young children, or people with severe liver or kidney di… |
| Tansy | Liver, kidney and bleeding harm. The thujone monograph lists liver inflammation and intestinal bleeding; the consumer reference adds kidney or liver damage. |
| Thunder god vine | Serious kidney and liver toxicity. NCCIH lists kidney damage and liver problems as serious risks and says rare deaths have been reported, possibly linked to certain… |
| Tribulus | Liver, kidney and nerve toxicity (case reports). Case reports describe severe liver and kidney injury and a seizure after tribulus products or herbal water. Case reports cannot s… |
| Turmeric | Kidney stones and oxalate. People prone to kidney stones are advised to check with a doctor first. One case describes kidney damage from oxalate with long-t… |
| Uva Ursi | Kidney disorders: contraindicated. The EU monograph lists kidney disorders as a contraindication. |
| Vijaysar (Indian kino) | Pregnancy, breastfeeding, children, liver and kidney: not established. No human study in pregnancy, breastfeeding or children was found. A rat study of one related compound (3'-hydroxypterostilbene) f… |
| White kidney bean extract | Poisoning from raw or undercooked kidney beans. Raw or insufficiently cooked kidney beans contain the lectin phytohaemagglutinin; nausea, vomiting and diarrhea usually start 1 t… |
| Wild ginger (Canadian) | Kidney damage and cancer risk from aristolochic acid. The FDA names Asarum canadense in an import alert for plants that can contain aristolochic acid, which it calls a potent carcinog… |
| Wild ginger (Canadian) | No treatment for aristolochic acid nephropathy. A 2023 review says aristolochic acid nephropathy has no effective treatment to delay or reverse the kidney damage, and that expos… |
| Wild yam | Kidney scarring in rats. Rats fed a wild yam extract for 28 days developed more kidney fibrosis and liver inflammation markers. The authors suggest long-t… |
| Willow bark | Risk: liver and kidney disease. EMA lists severe liver or kidney dysfunction, clotting disorders and G6PD deficiency as reasons not to use willow bark. Memorial … |
| Wormwood | Kidney injury from wormwood oil. A 1997 New England Journal of Medicine case report describes acute kidney failure after oil of wormwood bought online. |
| Xanthium (cang er zi, cocklebur) | Kidney injury. The 2023 case included oliguria progressing to anuria and a high creatinine, needing dialysis. Kidney risk at lower exposures was… |
| Yellow dock | Oxalate load and kidney stones. The plant contains 7 to 11 percent oxalic acid. A 2025 review links high Rumex intake to extra oxalate in urine and calcium oxala… |
| Yellow dock | Oxalate poisoning after eating large amounts. Fatal oxalate poisoning has been reported in people and sheep after eating large amounts of yellow dock leaves, with low calcium,… |
| Herb | What its guide documents |
|---|---|
| Aconite (monkshood) | Heart rhythm and nerve poisoning (aconitine). Aconitine and related alkaloids can cause dangerous heart rhythm problems and numbness or tingling. Deaths mostly occur within 24… |
| Aloe vera | Heart medicine interaction (latex). Overuse of aloe latex may increase side effects of cardiac glycosides such as digoxin. |
| Arjuna | Possible interactions with heart, blood pressure and blood-thinning medicines. WebMD says arjuna may add to or change the effects of heart, blood pressure, cholesterol, blood-thinning, heart-rhythm and chest-… |
| Bala (country mallow) | Contains ephedrine-type stimulants. The FDA names Sida cordifolia (country mallow) as a plant source of ephedrine alkaloids, the stimulants banned in US supplements … |
| Bala (country mallow) | Heart rhythm and blood pressure risk. A case report linked a multi-ingredient supplement containing heart-leaf sida to a fast heart rhythm that stopped within 24 hours… |
| Bayberry (wax myrtle) | Sodium retention and higher blood pressure (tannins). A consumer reference says tannins in bayberry may increase sodium retention and fluid, which can raise blood pressure, and advise… |
| Birch leaf | Heart or kidney disease and fluid restriction. The EU monograph says birch leaf should not be used where less fluid intake is advised, for example severe heart or kidney diseas… |
| Bitter orange | Heart rhythm problems (palpitations, arrhythmia, heart attack, stroke). NCCIH says abnormal heart rhythms, heart attacks and strokes have been reported with bitter orange supplements, though most produ… |
| Bitter orange | Blood pressure and heart rate increases. A 2022 meta-analysis of 18 placebo-controlled trials found blood pressure rose after prolonged synephrine use and heart rate tend… |
| Bitter orange | Label accuracy and hidden synthetic stimulants. FDA researchers tested 59 bitter orange supplements. Only 5 of 23 products with a labeled synephrine amount were within 80 to 120… |
| Bitter orange | Medicine interactions and combined stimulants. NCCIH advises anyone taking medicines to talk to a health professional first. Products often add caffeine and other stimulants. A… |
| Bloodroot | Glaucoma, platelets and heart rhythm cautions. MSK advises avoiding bloodroot with glaucoma. In lab studies sanguinarine had antiplatelet effects and affected a sodium-potassiu… |
| Blue cohosh | Newborn stroke, heart attack and organ injury after use in labor. A 2008 systematic review found three case reports linking blue cohosh taken near delivery to a newborn stroke, a newborn heart at… |
| Blue cohosh | Heart toxicity case reports (supplement table). A published table of heart-related supplement case reports lists blue cohosh among a small group of herbs linked to heart problem… |
| Calotropis (arka) | Heart poisoning (cardiac glycosides). A case report says all parts of the plant are toxic and contain cardiac glycosides (cardenolides) with digoxin-like effects. A pa… |
| Chia | Blood pressure and blood sugar medicines. MSK says chia may add to the effect of blood pressure medicines and may lower blood sugar so could interact with diabetes treatme… |
| Cinchona bark | Heart rhythm problems. MedlinePlus lists fast or irregular heartbeat and asks about prolonged QT. A case report describes a dangerous rhythm in an older… |
| Coleus forskohlii (forskolin) | Blood pressure medicines (documented caution). Forskolin may add to the effect of blood pressure medicines; low blood pressure and fast heart rate are listed adverse reactions. |
| Corn silk | Potassium loss and kidney filtering (rat findings). In rats, a water extract increased potassium excretion and lowered a measure of kidney filtering at a high dose. |
| Corn silk | Interaction with diuretics, heart and diabetes medicines (theoretical). No human interaction study was found; the diuretic, potassium and blood sugar findings are a reason to ask a pharmacist. |
| Corydalis | Heart-rhythm changes. WebMD lists palpitations, chest pain or fainting and advises caution with heart-rhythm problems; a review advises caution in hear… |
| Couch grass | Documented risk: people who must limit fluids, severe heart or kidney disease. Because the herb is meant to raise urine flow, the tea is not recommended where a doctor advises limiting fluids, and the EU safe… |
| Dandelion | Possible high potassium in kidney failure, diabetes or heart failure. The EU committee says people with kidney failure, diabetes or heart failure should avoid it because of possible high potassium (h… |
| Eleuthero | Side effects: sleeplessness, irritability, fast heartbeat, headache. The EMA lists insomnia, irritability, rapid heartbeat and headache, frequency not known. |
| Evodia (wu zhu yu) | Heart rhythm (QT) concern. In guinea pigs, rutaecarpine prolonged the QT interval and raised the chance of ventricular fibrillation; it blocks the hERG pota… |
| Figwort | Possible heart-rhythm caution. A practitioner reference lists ventricular tachycardia as a contraindication. We could not verify a cardiac-glycoside-like action… |
| Foxglove | Poisoning of the heart (slow or irregular heartbeat). Every part of foxglove is poisonous and can slow the heart or make it beat irregularly. In one case the heart briefly stopped. |
| Foxglove | Link to the heart medicine digoxin. Foxglove contains digitalis, the same family of compounds as the prescription medicine digoxin. Digoxin itself is a purified drug… |
| Fritillaria (chuan bei mu) | Possible heart-rhythm and organ concerns (flagged, unproven). A review flags that peimine may block a heart-rhythm channel (hERG); a computer study predicted possible liver and kidney toxicit… |
| Goldenrod | Fluid intake and heart or kidney disease. Not suitable where less fluid is advised, such as severe heart or kidney disease. Preparations need enough fluid intake. |
| Graviola (soursop) | Blood pressure lowering (animals) and blood-pressure-medicine interaction. In animals graviola lowered blood pressure. MSK says it may add to the effect of blood-pressure medicines; clinical relevance has… |
| Guarana | Caffeine effects on heart and blood pressure. Caffeine stimulates the heart and central nervous system and can raise blood pressure. Case reports describe fast heartbeat and e… |
| Guarana | Interactions with stimulants, blood thinners and amiodarone. Combining with other stimulants may not be safe. Lab studies show antiplatelet activity, so bleeding risk with warfarin is possib… |
| Guayusa | Blood pressure rise and jitteriness. In two small trials blood pressure rose a few mmHg after an extract dose; jitteriness (women, higher dose), tremor and dry mouth … |
| Guayusa | Stimulant interaction (ephedrine). A consumer drug reference lists a major interaction with ephedrine and other stimulants, raising the risk of serious heart and bl… |
| Hawthorn | Possible interaction with digoxin and heart or blood-pressure medicines. Ask a pharmacist or prescriber before combining hawthorn with digoxin or other heart medicines. A small trial in 8 healthy people… |
| Hibiscus | Risk: additive blood-pressure lowering with blood pressure medicines (reasoned caution). Because hibiscus can lower blood pressure, taking it with blood pressure medicines could lower pressure further. This combination… |
| Hoodia | Blood pressure, heart rate and blood test changes. The trial found significant increases in blood pressure, pulse, heart rate, bilirubin and alkaline phosphatase on the extract. NC… |
| Horehound | Possible effects on blood sugar and blood pressure (medicine interactions). RxList, a consumer reference, says horehound may lower blood sugar and blood pressure and so may add to diabetes and blood-pressu… |
| Horehound | Heart rhythm and surgery cautions. RxList says horehound may cause irregular heartbeat in people with heart problems and advises stopping it at least 2 weeks before… |
| Horny goat weed | Heart rhythm and mood effects. MSK describes a case of fast irregular heartbeat and hypomania in a man with heart failure after 2 weeks of daily use, and advise… |
| Horsetail | Fluid intake, heart and kidney disease. The EU monograph says horsetail for urinary use should not be used where reduced fluid intake is recommended, for example severe … |
| Horsetail | Lithium and diuretic-herb case; low-potassium case. The monograph lists no interactions, but the EMA report describes lithium toxicity in a woman using a mixed herbal diuretic that … |
| Imperata (bai mao gen) | Potassium content and kidney or medicine caution. The review says high potassium content may contribute to the diuretic effect but gives no values. No source we read describes pot… |
| Isatis (ban lan gen) | Pulmonary arterial hypertension with Qing Dai. Case reports link Qing Dai (indigo naturalis) use in ulcerative colitis to pulmonary arterial hypertension; rat tissue work sugge… |
| Java tea (cat's whiskers) | Limit fluids: heart and kidney disease. The EU says not to use Java tea where reduced fluid intake is recommended, such as severe heart or kidney disease. Older German a… |
| Khat | Heart attack risk. A Yemen case-control study of 100 heart-attack patients and 100 controls linked khat chewing with higher odds of heart attack, ri… |
| Khat | High blood pressure, heart rhythm and heart muscle. A 2025 review links chewing with high blood pressure, acute coronary syndrome, cardiomyopathy and abnormal heart rhythms, but cal… |
| Kola nut | Heart, blood pressure and thyroid cautions. The EMA names heart rhythm problems, high blood pressure and an overactive thyroid among the conditions behind its cautions, beca… |
| Lemon verbena | Possible additive effect with blood pressure medicines. Because pooled trials found lower blood pressure on average, anyone taking blood pressure (or diabetes) medicines should ask a ph… |
| Licorice root | Raises blood pressure and lowers potassium. In pooled studies, regular intake of real licorice raised systolic blood pressure by about 5 mm Hg and lowered blood potassium. G… |
| Lily of the valley | Heart-active poisoning (digitalis-like). All parts contain cardiac glycosides such as convallatoxin. Swallowing them can slow or disturb the heartbeat, in the same way as… |
| Lovage | Kidney inflammation and heart- or kidney-related swelling. An encyclopedia says lovage root flushing should not be used in acute inflammatory kidney disease or in heart- or kidney-related … |
| Lycium root bark (di gu pi) | Possible added effect with diabetes and blood pressure medicines. Because animal studies point to lower blood sugar and pressure, ask a prescriber or pharmacist before combining the bark with suc… |
| Myrrh | Heart rate at high amounts. MSK says high doses may affect heart rate. |
| Noni | High potassium content. Noni contains a lot of potassium. People with kidney disease or on a potassium-restricted diet should talk to a health care provi… |
| Oleander | Poisoning of the heart (slow or irregular heartbeat). All parts of oleander contain cardiac glycosides that can cause a slow or irregular heartbeat and low blood pressure; deaths are … |
| Olive leaf | Possible added effect with blood pressure or diabetes medicines. Because trials show blood pressure and blood sugar effects, a prescriber should know about olive leaf use. No specific interactio… |
| Peppermint | Heartburn and reflux can get worse (documented risk). Peppermint oil by mouth can cause heartburn, and the EU monographs advise people with reflux or hiatal hernia to avoid peppermint… |
| Periwinkle | Possible added effect with blood pressure medicines. The same reference says vinpocetine may increase the blood-pressure-lowering effect of medicines for high blood pressure, and low… |
| Platycodon (balloon flower) | Licorice pairing raises platycodin D levels. One study found that pairing the root with licorice (Glycyrrhiza uralensis) raised blood levels of platycodin D. Licorice has its… |
| Pleurisy root | Cardiac glycosides and the heart. Milkweeds contain cardiac glycosides, which are poisonous to people and livestock. A consumer drug reference says pleurisy root h… |
| Pleurisy root | Digoxin and other heart medicines. A consumer drug reference lists digoxin as a major interaction and advises against the combination. PeaceHealth lists beta-blocke… |
| Pleurisy root | Water pills and low potassium. The consumer reference says potassium-lowering water pills may raise the risk of heart effects from the root. |
| Poison hemlock | Heart rhythm and circulation effects. Reports describe a slowed or faster heart rate, abnormal rhythm and in some cases cardiac arrest or circulatory collapse. |
| Pueraria mirifica (kwao krua) | Heart-rhythm case report. A case report describes long QT and torsade de pointes in a young woman with a gene variant after a supplement. |
| Restharrow | Fluid-restriction conditions (heart or kidney disease, oedema). The EMA says restharrow root must not be used where reduced fluid intake is recommended, e.g. severe heart or kidney disease, and… |
| Rosemary | Children under 12 and hot baths with high blood pressure. Oral and bath use is not recommended under 12 because of lack of data, and people with high blood pressure should be careful with… |
| Sarpagandha (Indian snakeroot) | Interactions with heart, Parkinson and mood medicines. The label advises caution with digoxin or quinidine, avoiding levodopa and MAO inhibitors, and notes added sedation with alcohol … |
| Scotch broom | Heart rhythm and heart disease. The reference advises people with heart disease not to use it because it might affect heartbeat. EFSA names changes in heart elec… |
| Scotch broom | Blood pressure: possible rise. The reference says the plant might narrow blood vessels and raise blood pressure, worsening hypertension. |
| Senna | Low blood potassium and fluid or salt imbalance. Frequent diarrhoea after long use can lower potassium (muscle weakness, tiredness, heart rhythm problems). Long-term use may also… |
| Stinging nettle | Possible interaction with diuretics, blood pressure medicines and liver-processed drugs. Based on animal studies, nettle may add to diuretics and blood pressure medicines and may inhibit CYP450 enzymes. Clinical releva… |
| Stone root | Possible interactions with blood thinners, blood pressure medicines and diuretics. Hobbs says it may interact with anticoagulants and blood pressure medicines; Healthline raises dehydration and interactions from … |
| Tangerine peel (chen pi) | Synephrine content (mild stimulant compound). One review describes synephrine in citrus peel as sympathomimetic (acting like a mild stimulant) and linked with minimal adverse … |
| Taxillus (sang ji sheng) | Liver and embryo toxicity, and liver or heart disease. A 2022 review says the plant shows liver toxicity and embryo toxicity and may cause complications in some people with liver or he… |
| Uncaria (gou teng) | Possible extra blood pressure fall with blood pressure medicine. Because blood pressure lowering is seen in animals, an added effect with antihypertensive drugs is a theoretical concern; no huma… |
| Yellow dock | Gut irritation, diarrhea and low potassium. Fresh rhizome can irritate the mouth and gut and cause vomiting. Reviews list nausea, vomiting, diarrhea and low potassium; anthr… |
| Yerba mate | Caffeine content and stimulant effects. Mate leaf contains caffeine, so the drink can be stimulating. Reported side effects in trials included trouble sleeping, fast hea… |
| Yohimbe | Heart rhythm, blood pressure and seizure risk. NCCIH links yohimbine to irregular heartbeat, blood pressure problems, heart attacks and seizures. MSK lists high blood pressure,… |
| Herb | What its guide documents |
|---|---|
| Black cohosh | Hormone-sensitive cancers and cancer medicines. Safety is uncertain for women with breast or uterine cancer. It may interfere with tamoxifen or add toxicity with some chemothera… |
| Chamomile | Estrogen-like effects and birth control. Chamomile might have estrogen-like effects, may reduce the effect of birth control pills (preliminary), and could worsen estrogen… |
| Chasteberry | Hormone-sensitive conditions caution. Chasteberry may not be safe for women with hormone-sensitive conditions such as breast, uterine or ovarian cancer; ask a clinicia… |
| Chasteberry | Hormone medicines and contraceptives. Laboratory studies suggest chasteberry may reduce the effect of birth control pills and other hormone medicines. The clinical mea… |
| Cissus quadrangularis | Hormone effects. Trials measured bone-related hormones such as parathyroid hormone; claims about sex hormones were not verified in the sources rea… |
| Cistanche | Hormone-sensitive conditions: laboratory caution. In laboratory work an aqueous C. deserticola extract increased the viability of breast cancer cells in a dish, yet did not increa… |
| Curculigo (kali musli) | Possible hormone effects: caution. Because animal work shows effects on sex hormones, people with hormone-sensitive conditions or on hormone medicines should ask a … |
| Cuscuta seed (tu si zi) | Hormone medicine interaction (possible). The review says seed flavonoids might influence androgen, estrogen and progesterone receptors, possibly affecting contraceptives … |
| Dong quai | Hormone-sensitive cancers caution. Lab extracts stimulated breast cancer cells and promoted growth of estrogen receptor-positive tumors in a mouse model, so people … |
| Flaxseed | Oestrogen-like effects and hormone-sensitive tumours. The EMA says long-term use may have an oestrogen-like effect and is not recommended for women with hormone-dependent tumours. MSK… |
| Hoodia | Adrenal hormone enzyme inhibition (lab). MSK says lab studies found a hoodia compound inhibits several adrenal steroid-making enzymes; clinical meaning is not stated. |
| Hops | Plant estrogen (8-prenylnaringenin). Hops contain 8-prenylnaringenin, described as a potent plant estrogen. Long-term safety of using it as a treatment still needs st… |
| Horny goat weed | Estrogen-like activity and hormone-sensitive cancers. Laboratory work suggests icariin may increase estrogen production and aromatase, and derivatives show estrogen-like activity. MSK… |
| Japanese knotweed (hu zhang) | Risk: estrogen-like activity. Resveratrol has estrogen-like properties in the lab, so caution is advised in hormone-sensitive cancers. |
| Kudzu | Estrogen-like activity and hormone-sensitive cancers. MSK says kudzu has estrogen-like activity, so people with hormone-sensitive cancers such as ER-positive breast cancer should avoi… |
| Pleurisy root | Possible weak estrogen-like effect. The consumer reference says the root may act weakly like estrogen and could lessen the effect of estrogen medicines. |
| Pueraria mirifica (kwao krua) | Strong estrogen-like activity and hormone-sensitive conditions. The root contains potent plant estrogens (miroestrol, deoxymiroestrol). No human safety data were found for people with hormone-s… |
| Pueraria mirifica (kwao krua) | Rat toxicity: estrogen-like effects and mild liver change. In rats, 28-day oral exposure caused estrogen-like effects on ovary, uterus and breast tissue and mild fat change in liver cells … |
| Red clover | Estrogen-like activity and hormone-sensitive cancers. Lab studies suggest the extract may stimulate ER-positive breast cancer cells, so people with hormone-sensitive cancers are advis… |
| Rooibos | Estrogen-like compounds and hormone-sensitive cancers. MSK says rooibos contains compounds with estrogenic activity, so people with hormone-sensitive cancers should be cautious. |
| Scotch broom | Pregnancy: uterine stimulation and miscarriage risk. A consumer drug reference rates Scotch broom likely unsafe by mouth in pregnancy and says it might cause miscarriage. Its alkaloi… |
| Shatavari | Estradiol (estrogen) levels. Several trials of extracts reported higher blood estradiol. Plant compounds in the root can act weakly like estrogen. What this m… |
| Spearmint | Possible hormone effects: caution with hormone-related conditions. Because spearmint tea changed sex-hormone and gonadotropin levels in trials, people with hormone-related conditions or on hormone… |
| Tribulus | Pregnancy, breastfeeding and prostate cancer cautions. No source we read shows safety in pregnancy, breastfeeding or children. MSK advises people with prostate cancer to check with the… |
| Vidari kanda | Plant estrogen-like compounds (isoflavones). The tuber contains daidzein, genistein, biochanin A and puerarin. In the lab these can act like weak estrogens. Effects in people… |
| Wild yam | Estrogen-like effects and hormone-sensitive cancers. Because wild yam has estrogenic effects, people with hormone-sensitive cancers should talk to a physician before using it. |
| Herb | What its guide documents |
|---|---|
| Acai | Raw juice and Chagas disease. Raw or unpasteurized acai fruit and juice can carry parasites; outbreaks of acute Chagas disease have been linked to raw juice in… |
| Aconite (monkshood) | Raw versus processed root (fuzi). Long boiling or steaming turns the most toxic alkaloids into less toxic ones, but processing lowers the risk without removing it,… |
| Aconite (monkshood) | Medicinal liquors and absorption. Alcohol-based medicinal liquors were the most common route of poisoning in one Chinese analysis, because alcohol increases absorp… |
| African potato | Bone marrow suppression in an HIV trial. A trial of the extract in people with HIV/AIDS was stopped by its safety monitoring committee because of apparent bone marrow sup… |
| African wormwood | Safety evidence is thin. A 2025 study cited case reports of harm linked to Artemisia teas and called for monitoring of African wormwood use. Safety in pre… |
| African wormwood | Unproven COVID-19 remedies and misinformation. WHO Africa and the French Academy of Medicine said Artemisia products for COVID-19 need proper testing and advised against Artemi… |
| Agarwood (chen xiang) | Incense smoke and indoor air. A 2016 review says the safety of agarwood incense smoke needs more study; a 2026 lab study found incense particles damaged human … |
| Agarwood (chen xiang) | Overharvesting and protected status. A. malaccensis is Vulnerable on the IUCN Red List and in CITES Appendix II; wild trees are cut in search of resin and illegal tra… |
| Ajwain | Thin clinical and safety evidence overall. A 2026 review says clinical investigations of ajwain remain limited and safety must still be established. |
| Ajwain | Chemical make-up varies between seed populations. In 14 seed populations, oil yield and thymol content differed and two chemical types were found. |
| Albizia (mimosa tree bark) | Look-alike species. Albizia lebbeck is a separate accepted species; facts for one should not be assumed for the other. |
| Alfalfa | Lupus and autoimmune flares (tablets and seeds). MSK says people with systemic lupus should avoid alfalfa tablets because they may cause a relapse. Seeds contain L-canavanine, li… |
| Alfalfa | Gout, blood urate and urea. MSK says alfalfa may raise blood urate and urea and advises avoiding it in gout because of its purine content. |
| Alisma (ze xie) | Electrolyte and fluid disturbance with large or long-term use. Historical adverse-reaction records link large or long-term amounts to electrolyte imbalance, blood in urine, acidosis and stomac… |
| Aloe vera | Laxative action of aloe latex. Aloe latex acts as a laxative but causes cramps and diarrhea. FDA found inadequate data on its safety and effectiveness as an ove… |
| Aloe vera | Possible cancer concern (whole-leaf extract). IARC classifies non-decolorized whole-leaf extract as a possible human carcinogen, based on animal studies of the gut in rats and… |
| American ginseng | Wild harvest and conservation. Wild American ginseng is listed on CITES Appendix II after long-term harvesting. This concerns the plant, not human health. |
| Amomum (sha ren) | Species and product mix-ups. Chinese medicine uses three plant sources for this herb, and related cardamom-type fruits are sold with similar names. |
| Angelica | Sun sensitivity from furanocoumarins. Angelica archangelica preparations contain furanocoumarins; related linear furanocoumarins cause skin reactions with UVA light. T… |
| Angelica | Possible long-term cancer risk from furocoumarins. The EU committee noted that a related medicine (oral 8-MOP plus UVA, PUVA) raises skin cancer risk, and that herbal exposure is a… |
| Angelica dahurica (bai zhi) | Sun-sensitivity risk from furanocoumarins (possible). The root contains furanocoumarins, a group that can cause skin reactions with sunlight in other carrot-family plants. A reaction … |
| Angelica dahurica (bai zhi) | Overuse warning. The review warns that vast and irrational use may cause spasm and paralysis. |
| Apricot kernel (bitter) | Warning on bitter apricot seed products. In May 2024 the FDA told people to stop using three bitter apricot seed products found to contain high amygdalin levels, and advi… |
| Apricot kernel (bitter) | Cancer treatment claims (laetrile, amygdalin, 'vitamin B17'). No good evidence supports laetrile or amygdalin for cancer. Cochrane found no qualifying controlled trials and judged risk agains… |
| Apricot kernel (bitter) | Higher cyanide risk with some foods, vitamin C and B12 deficiency. NCI says raw almonds, crushed fruit pits, foods with beta-glucosidase (such as celery, peaches, bean sprouts, carrots) and high o… |
| Apricot kernel (bitter) | Unreliable products bought online. Cochrane warns that products bought online may come from questionable sources and may be contaminated, because these markets lack… |
| Arjuna | Iron absorption. WebMD says tannins in arjuna may reduce iron absorption. |
| Arnica | Serious harm if swallowed. Case reports describe stomach and bowel distress, internal bleeding, fast heartbeat, breathing difficulty and coma after eating t… |
| Ashitaba | Sun sensitivity (furanocoumarins). Ashitaba sap contains very little furanocoumarin (under 0.01%); EFSA judged skin exposure unlikely and a 2013 animal skin test fo… |
| Ashoka | Vulnerable wild supply. The tree is described as vulnerable, with very small wild populations in the Western Ghats, driven by harvesting for the herbal m… |
| Ashwagandha | Thyroid effects (documented risk). Case reports describe thyrotoxicosis after use. NCCIH advises people with thyroid disorders to avoid it or use it only with medic… |
| Astragalus | Possible worsening of autoimmune disease. NCCIH says astragalus might worsen autoimmune symptoms and people with these conditions should avoid it. |
| Astragalus | Safety when taken by mouth. NCCIH says oral use up to 60 grams a day for as long as 4 months did not seem to cause adverse effects, but a thorough safety eva… |
| Atractylodes | Mix-up with cang zhu (Atractylodes lancea). Bai zhu is often confused with cang zhu, a different species with different traditional uses, so the Latin name on the label matt… |
| Autumn crocus (colchicum) | Mistaken for wild garlic. The leaves look like edible wild garlic when there are no flowers, and mix-ups have caused serious poisonings. |
| Autumn crocus (colchicum) | Narrow margin and no antidote. The gap between a helpful and a harmful amount of colchicine is small, and there is no specific antidote; treatment is supportive. |
| Autumn crocus (colchicum) | Bone marrow suppression and blood counts. Low blood cell counts, including low white cells and platelets, have been reported even at medicine doses, and bone marrow depres… |
| Autumn crocus (colchicum) | Animals, hay and milk. Cattle were poisoned by autumn crocus in mown meadow forage; colchicine was expected in milk and the milk was withheld under EU r… |
| Baikal skullcap | Withdrawn baicalin product (Limbrel). A US medical food for osteoarthritis made from a baicalin and catechin extract was withdrawn in 2018 at the FDA's request over ra… |
| Barberry | Metformin level lowered by a related berberine herb. NCCIH reports a goldenseal extract lowered metformin levels by about 25 percent in healthy adults. That was goldenseal, not barbe… |
| Bayberry (wax myrtle) | Cancer-linked chemical. Two consumer references say bayberry contains a chemical that can cause cancer; the compound is not named in the text we read. |
| Belladonna (deadly nightshade) | Mistaken for an edible plant. Two adults ate raw leaves taken for wild lettuce and needed hospital care. |
| Belladonna (deadly nightshade) | Unpredictable amounts in homeopathic teething tablets. FDA lab tests found belladonna amounts that were inconsistent and sometimes far above the label in certain teething tablets; pare… |
| Belladonna (deadly nightshade) | Contraindicated conditions. The German reference lists narrow-angle glaucoma, enlarged prostate with urine left in the bladder, fast irregular heartbeat, bow… |
| Belladonna (deadly nightshade) | Hospital treatment is supportive. Care is mostly supportive with benzodiazepines for agitation; physostigmine may be used for severe cases, and diphenhydramine and… |
| Bergamot | Very heavy Earl Grey tea drinking. A 2002 Lancet letter linked very heavy Earl Grey tea drinking to muscle cramps, twitching and vision problems in one man. |
| Betel nut (areca nut) | Oral cancer risk. IARC concluded that betel quid, with or without tobacco, and areca nut are carcinogenic to humans. WHO lists betel quid among the… |
| Betel nut (areca nut) | Oral submucous fibrosis. About 5% of areca nut chewers develop this scarring of the mouth lining, which can limit mouth opening and can become cancer. |
| Betel nut (areca nut) | Throat and food-pipe cancer (with tobacco). IARC linked betel quid with tobacco to cancers of the pharynx and oesophagus. |
| Betel nut (areca nut) | Dependence. Reviews describe a dependence syndrome driven by arecoline acting on several brain chemical systems; over half of current users i… |
| Bilberry | Safety information that is missing. The EU summaries report no side effects at the time of assessment and limit use to adults (fresh fruit, up to four weeks) or adul… |
| Bitter kola | Long-term and dose safety not established. Reviews and the survey authors say doses are not standardised and that toxicology across age groups, chronic use and plant-drug i… |
| Bitter Melon | Product and preparation variability. Trials used different preparations (parts of the plant, capsules, powders, juice), so results for one product cannot be assumed f… |
| Bitter orange | Anti-doping status (sport). NCCIH notes the NCAA lists synephrine (bitter orange) as a banned stimulant. |
| Black cohosh | Do not confuse with blue cohosh. Blue cohosh is a different herb; it may raise blood pressure and blood sugar and cause chest pain, and use to induce labor has be… |
| Bladderwrack | Iodine content and thyroid effects. Bladderwrack is rich in iodine. The EU herbal committee concluded that iodine-containing bladderwrack products can influence thyr… |
| Blessed thistle | Missing safety testing. EMA says tests on reproductive toxicity, genotoxicity and carcinogenicity have not been performed, so long-term safety data are s… |
| Bloodroot | Black salve and tissue destruction. Bloodroot is the main ingredient in black salve. Used on skin lesions it has caused disfigurement, scarring, worsening lesions an… |
| Bloodroot | Cancer persisting after black salve. In Australian pathology records, 409 people had used black salve on 475 lesions; 18% of lesions were benign and cancer persisted … |
| Bloodroot | Oral leukoplakia from old mouth products. A 2001 study linked a sanguinarine toothpaste and rinse to white mouth patches (leukoplakia), which can sometimes lead to oral ca… |
| Blue flag | Irritation and vomiting from the root. The rhizome irritates the mouth, throat and stomach, and eating plant parts can cause nausea, drooling, vomiting, stomach pain, d… |
| Blue flag | Skin irritation from sap and rootstock. Touching the sap, seeds or rootstock can irritate the skin; NC State describes it as minor and short-lived. |
| Blue lotus | Altered mental status after vaping or infusion. Five hospital patients had confusion, sedation and changed perception after vaping blue lotus products (four) or an infusion (one… |
| Blue lotus | Psychiatric symptoms reported. A 2026 short review reports agitation, derealisation and anxiety, and two vignettes with hypomanic and psychotic features, after … |
| Blue lotus | No safety data for safe amounts. Safety data on the plant and its extracts are limited; safe amounts, long-term effects and drug interactions are not known. |
| Blue lotus | Vaping or smoking resin (untested way of use). Resin was shown to turn into aerosol in a rebuildable dripping atomizer e-cigarette; this way of use has not been tested for safe… |
| Blue vervain | Little modern safety testing. Vervain is thought to be fairly safe but has not had meaningful modern safety testing. AHPA added a blue vervain entry to its Bot… |
| Borage | Seizure case report. Memorial Sloan Kettering reports one case of continuous seizure activity in a healthy 41-year-old woman after a week of borage oi… |
| Buchu | Lithium and dehydration. EBSCO says people taking lithium should use buchu only under a doctor's supervision, because a diuretic effect could cause dehydr… |
| Bugleweed | Lowered thyroid function in people who do not need it. Drugs.com warns that heavy use by people with thyroid disease, or use by healthy people, may cause a potentially harmful drop in … |
| Bugleweed | Interference with radioisotope thyroid tests. EBSCO says bugleweed may interfere with diagnostic tests that use radioactive isotopes to evaluate the thyroid. Tell the testing … |
| Bugleweed | Underactive or enlarged thyroid. Both consumer references say people with an underactive thyroid should not use bugleweed, and EBSCO adds people with an already e… |
| Bupleurum | Lung inflammation with the formula Xiao Chai Hu Tang. MSK reports interstitial pneumonitis, which can be fatal, with Sho-saiko-to: about 74 cases, roughly 1 in 20,000 users. It is a f… |
| Burdock root | Use with water tablets (diuretics). The EU monograph does not recommend using burdock root together with synthetic diuretics, and says it should not replace them. |
| Butcher's broom | Safety: see a doctor for warning signs. Sudden leg swelling, leg ulcers, skin inflammation or hardening, heart or kidney insufficiency, or rectal bleeding need a doctor,… |
| Butterbur | Safety: pyrrolizidine alkaloids in the raw plant. The raw butterbur plant contains pyrrolizidine alkaloids, which can damage the liver and lungs and may cause cancer. Only product… |
| Butterbur | Guideline recommendation withdrawn. The American Academy of Neurology recommended butterbur for migraine prevention in 2012 but stopped recommending it in 2015 becau… |
| Butterbur | Skin use of PA-containing products. NCCIH says products containing PAs may not be safe on the skin because PAs could be absorbed through cuts or scrapes. |
| Calamus (sweet flag) | Cancer-causing and gene-damaging potential of asarone. EMA says alpha- and beta-asarone from calamus are genotoxic and cause liver cancer in rodents. |
| Calamus (sweet flag) | US food prohibition. US federal rule deems food with added calamus, its oil or extract adulterated. |
| Calamus (sweet flag) | Variety differences in asarone content. Asarone ranges from none detected in a diploid variety to very high levels in a tetraploid one, so the label rarely tells the ris… |
| Calamus (sweet flag) | EU exposure advice. EMA advised keeping asarone to a minimum and preferring diploid varieties; a temporary limit of about 115 micrograms a day was pr… |
| Calamus (sweet flag) | Skin irritation and sensitisation. A 2025 lab-model study classed the rhizome oil as an irritant and a moderate-potency sensitiser. |
| Calendula | Age limits for use (documented caution). The EU summary says skin use is for people over 6 and mouth or throat use for people over 12, and to see a doctor if symptoms wor… |
| California poppy | Product strength varies widely. In eight commercial products, californidine ranged from 0.13 to 2.55 mg per gram, so two products can differ a lot. |
| Calotropis (arka) | Eye injury from the milky latex. Latex in the eye caused corneal swelling, light sensitivity and blurred vision in hospital series. Most eyes recovered in days to… |
| Calotropis (arka) | Skin application. The heart-collapse case involved skin application as well as swallowing, so skin use is not a safe alternative to swallowing. |
| Camu camu | Loss of vitamin C when the fruit is dried. Spouted-bed drying of camu camu pulp lost 45 to 64% of ascorbic acid in one lab study, so powders may hold less vitamin C than th… |
| Capillary wormwood (yin chen hao) | Long-term safety not established. A 2026 review says systematic long-term safety data for the formula are lacking and that claims of high safety and low toxicity n… |
| Cascara sagrada | Dependence and bowel function with long-term use. Using stimulant laxatives for a long time may lead to the bowel not working properly and reliance on laxatives. Use no longer tha… |
| Cascara sagrada | Darkened bowel lining and urine changes. Long-term use may darken the lining of the bowel, and cause protein or blood in the urine and yellow or red-brown urine. |
| Cascara sagrada | Bowel conditions and dehydration where it should not be used. Not for bowel blockage or narrowing, appendicitis, inflammatory bowel disease, unexplained belly pain or severe dehydration. |
| Cassia seed (jue ming zi) | Reported harm in seed adverse-event reports. A 2026 review of adverse events from medicinal and edible seeds listed Cassiae semen among seeds with reports, mostly linked to e… |
| Cat's claw | May make the immune system more active (risk in autoimmune disease). NCCIH says cat's claw might stimulate the immune system, which could increase symptoms of autoimmune diseases. People with these … |
| Catnip (herb for people) | Shorter sleep after a sedative (mice). In mice, catnip shortened sleeping time after a sedative drug and raised seizure susceptibility. This is a possible interaction s… |
| Catuaba | Tropane alkaloids in some products. About half of tested samples contained tropane alkaloids, which come from Erythroxylum vacciniifolium bark, not Trichilia catigua. |
| Centaury | Peptic ulcer. The EU monograph lists peptic (stomach or gut) ulcer as a reason not to use centaury medicines. |
| Centaury | Missing safety testing. The EU monograph says tests for reproductive toxicity, genotoxicity and carcinogenicity have not been performed. |
| Chaparral (creosote bush) | Form matters: tea versus capsules and tinctures. In a National Academies review only 1 of 15 liver cases involved tea; NDGA dissolves poorly in water. The authors treat this as a… |
| Chia | Choking and food-pipe blockage from dry seeds. Dry seeds swell with liquid (MSK: up to 27 times their weight) and can lodge in the throat or esophagus; a case report describes … |
| Chicory root | Gas, bloating and rumbling (tolerance). A review of 103 trials counted bloating, flatulence and rumbling as tolerance effects of nondigestible carbohydrates, including i… |
| Chicory root | Occupational dust asthma. A worker in a chicory inulin factory developed nose and eye symptoms and asthma from dry chicory root dust. |
| Chinese arborvitae seed (bai zi ren) | Look-alike confusion with Thuja occidentalis. Thuja (eastern arborvitae) leaf contains thujone, a nerve toxin per EU regulators. Platycladus seed is a different plant part and… |
| Chinese asparagus root (tian men dong) | Safety data are thin. No adverse events are documented, but there are no human studies. A 14-day mouse study of one saponin extract found no liver or k… |
| Chinese asparagus root (tian men dong) | Look-alike and mixed roots. The root is often mixed with roots of nine related Asparagus species, so a product may not be what its label says. |
| Chinese yam (shan yao) | Look-alike with wild yam. Chinese yam is a different plant from wild yam (Dioscorea villosa), which is sold for hormone claims. Evidence for one species sh… |
| Chinese yam (shan yao) | Human safety data are thin. The sources read give no drug-interaction, pregnancy, liver or allergy information for Chinese yam supplements, so none can be cl… |
| Chirata | Threatened wild plant. A 2016 review says over-collection and habitat loss have pushed wild chirata toward extinction and calls it critically endangered. |
| Chitrak (Ceylon leadwort) | Skin irritation and blistering allegations. A rabbit study found a moderate skin irritant effect from a root extract. A review mentions allegations of blistering (vesicant) … |
| Chlorella | Immune stimulation and autoimmune conditions. A 2025 scoping review listed chlorella among 15 herbal supplements with the most robust evidence of immune-stimulating properties… |
| Chrysanthemum | Pesticide residues in products. A study of 111 chrysanthemum products from China found pesticide residues; brewing moved part of them into the infusion, and the … |
| Chrysanthemum | Authenticity and cultivar identification. A 2020 review says methods to tell cultivars apart and confirm authenticity are lacking, and that more safety evaluation of ju hu… |
| Chuanxiong | Reactions to injections. A review says Chinese medicine injections can cause pseudo-allergic reactions on the first dose; its summary does not name chuanx… |
| Chuchuhuasi | Alcohol-based traditional preparations. Traditional preparations are usually macerations in rum or other alcohol, which matters for people who avoid alcohol or take inte… |
| Cilantro | Cyclospora and food-borne infection risk. Fresh cilantro has been linked to cyclosporiasis outbreaks; CDC says washing may not remove the parasite. |
| Cinnamon | Skin irritation. Cinnamon oil or powder on the skin may cause irritation or contact dermatitis. |
| Cinnamon | Species and label confusion. Labels may not say which cinnamon species or plant part was used, and these differ in chemistry (notably coumarin), so products a… |
| Cinnamon | The cinnamon challenge. Swallowing dry cinnamon powder as an internet dare is unsafe and can cause serious harm. |
| Cinnamon twig (gui zhi) | Species and plant-part labelling. Products may not state species or plant part, and these differ in chemistry. |
| Clubmoss (lycopodium) | Lung harm when spores are inhaled. A case report describes lung inflammation with granulomas after a man inhaled Lycopodium spores while fire-breathing. The cause w… |
| Clubmoss (lycopodium) | Look-alike with Huperzia serrata (huperzine A). Huperzine A comes from a different club moss, Huperzia serrata. Its medicine-interaction cautions should not be assumed for or di… |
| Coltsfoot | Teas and herbal infusions as an exposure route. EFSA found a possible concern for frequent, high consumers of tea and herbal infusions, and said supplements from PA-producing pl… |
| Comfrey | Possible cancer risk (animal data). Memorial Sloan Kettering says the alkaloids are mutagenic and carcinogenic and animal experiments suggest liver cancer. Human can… |
| Comfrey | Regulatory action on oral products. In 2001 the US FDA advised supplement makers to remove comfrey products from the market; comfrey is reported prohibited in Austra… |
| Comfrey | Confusion with foxglove. Memorial Sloan Kettering reports accidental poisonings, including one fatal case, when foxglove was mistaken for comfrey. |
| Comfrey | Species and product variability. Comfrey species differ and products vary; EU regulators require the alkaloid content to be specified for each product. |
| Common sorrel | Anthraquinone-related adverse effects (Rumex genus). A review of Rumex species discusses anthraquinone-related side effects as a toxicological concern. The abstract gives no detail s… |
| Coptis (goldthread) | G6PD deficiency and the Singapore ban. Coptis and berberine were banned in Singapore from 1978 after being linked to neonatal jaundice and kernicterus in G6PD-deficient… |
| Cornflower (bachelor's button) | Eye products must be sterile. Anything used in the eyes should be sterile; homemade flower waters or teas are not. Contaminated eye products have caused infect… |
| Costus root (mu xiang) | Endangered plant and legal status. A 2019 study describes costus as on CITES Appendix I and Critically Endangered (IUCN), with wild collection banned in India. |
| Costus root (mu xiang) | Confusion with Aristolochia ('qing mu xiang'). The name mu xiang covers several roots including Aristolochia debilis, whose aristolochic acids are kidney-toxic and carcinogenic… |
| Costus root (mu xiang) | Adverse reactions and thin safety data. A 2025 review says several studies found extracts may cause adverse reactions; a 2020 review says very little safety and toxicity… |
| Cramp bark | Name confusion with black haw. Black haw (Viburnum prunifolium) is sometimes also sold as cramp bark, so labels may refer to a different plant. |
| Cryptolepis | Malaria is an emergency; herbal-only treatment risk. WHO says untreated falciparum malaria can become severe and fatal within 24 hours and recommends artemisinin-based combinations. … |
| Cryptolepis | Raised alkaline phosphatase and uric acid in treated patients. In the human studies, alkaline phosphatase stayed raised and uric acid rose during treatment (uric acid normalised by day 28). An… |
| Cryptolepis | Sustainability of root harvesting. Harvesting the root removes the plant, which authors say could threaten wild populations. |
| Dendrobium (shi hu) | Immune response and vaccination. In healthy volunteers, a dendrobium water extract changed immune markers, but neutralizing antibody levels after COVID-19 vaccina… |
| Dendrobium (shi hu) | Wild plant conservation. A 2026 study calls wild D. officinale critically endangered from overharvesting and habitat loss; cultivation is the alternative. |
| Devil's claw | Adults only. The EU summary says devil's claw root medicines should only be used in adults. The site page cites the EU monograph as not recomm… |
| Devil's claw | Long-term safety not established. The 2008 safety review found no reports of chronic toxicity but called for more long-term safety data. |
| Devil's club | Misleading 'Alaskan ginseng' labelling. The 2018 review says selling the plant as 'Alaskan ginseng' was banned in the US because the claim was misleading. It is in the g… |
| Elecampane | Look-alike root confusion (Muxiang names). Three different roots are sold as Muxiang in Chinese medicine, and elecampane is one. Check the botanical name and plant part on … |
| Eleuthero | Use under age 12. EMA says use in children under 12 is not established. |
| Eucalyptus | Alcohol in tinctures. The EMA limits the leaf tincture to adults partly because of its alcohol content. |
| Eucommia (du zhong) | Possible beta-receptor blocking (lab finding). In a fat-cell assay reported with the 2011 trials, the bark extract reduced isoproterenol-stimulated fat breakdown, consistent wi… |
| Eucommia (du zhong) | Skin sensitisation and cosmetic use. A 2026 assessment of aqueous bark extract in cosmetics found no skin or eye toxicity concern or genotoxicity in lab tests on the … |
| Eyebright | Safety of homemade eye washes and teas applied to the eye. The EU herbal committee said that applying homemade eyebright tea or compresses to the eye is not hygienic and not safe, and that… |
| Eyebright | Eye infection or irritation from non-sterile products. Eye products can cause infection if contaminated; FDA says stop use and get care for discharge, pain, vision change or discomfort. |
| Eyebright | Delay in treating a serious eye problem. Eye pain, light sensitivity, vision changes, very red eyes, or red sticky eyes in a baby under 30 days need prompt medical care a… |
| False unicorn root | Vomiting with large amounts (historical report). A 19th-century dispensatory says large amounts of the root cause vomiting and that it was reported to poison cattle. |
| False unicorn root | Threatened species, wild harvest and product mix-ups. The plant is on United Plant Savers' Critical list because harvesting the root kills it. Products are mostly wild-collected and h… |
| Fennel | Estragole content and cancer-risk limits. Fennel contains estragole, which the EU committee describes as a genotoxic carcinogen in rodents (liver tumors in mice). The EU s… |
| Feverfew | Adults only. The EU summary says feverfew herb medicines should only be used in adults. |
| Flaxseed | Choking and bowel blockage without enough fluid. The EMA says linseed taken without enough fluid can swell and block the throat, gullet or bowel. It is not for people with swallo… |
| Forsythia | Product and fruit-stage variation. Harvest time, origin, processing and storage change marker compounds, and unripe and ripe fruit differ. Formulas such as Lianhua … |
| Foxglove | Mistaken for comfrey or borage. Foxglove leaves have been mistaken for comfrey and borage, and people were poisoned after drinking tea or eating a pie made from … |
| Fritillaria (chuan bei mu) | Incompatibility with processed aconite (fuzi). Traditional Chinese medicine lists Fritillaria bulb and processed aconite as an incompatible pair. A rat and cell study found Fri… |
| Fritillaria (chuan bei mu) | Wild harvest and conservation. Chuan bei mu is described as rare and endangered and as a Grade III protected wild medicinal species in China; over-harvesting is… |
| Garlic | Skin burns from raw garlic. Fresh raw garlic on the skin may cause severe irritation and chemical burns. |
| Gentian | Laboratory signal for some plant compounds (xanthones). Some xanthones in the plant gave positive results in a bacterial test (AMES test). This is a laboratory finding and was not teste… |
| Gentian | Use under 18 not established. Use in children and adolescents under 18 is not recommended because adequate data are lacking. The EU summary says gentian root m… |
| Gentian | Duration and alcohol-based products. The committee advises seeing a doctor or practitioner if symptoms last longer than 2 weeks or get worse. Tinctures and liquid ext… |
| Ginger | Gallstones. Memorial Sloan Kettering advises people with gallstones to avoid ginger supplements because ginger may increase bile flow. |
| Goldenrod | Combination with water pills. The EU monograph does not recommend taking goldenrod with synthetic diuretics. |
| Goldenrod | See a doctor for fever, painful urination, blood in urine. Fever, painful urination, spasms or blood in the urine need medical assessment rather than self-treatment. |
| Goldenseal | Conservation: wild plants overharvested. Wild goldenseal has been overharvested and is available only in limited amounts; growing it commercially is possible but expensiv… |
| Gravel root (Joe-Pye weed) | Skin application risk. RxList rates use on broken skin as likely unsafe because toxins can be absorbed quickly; for unbroken skin it says information is… |
| Graviola (soursop) | Reduced uptake of imaging tracers. In animals graviola decreased uptake of radiopharmaceuticals used in imaging; MSK advises avoiding it before scans such as PET. |
| Graviola (soursop) | Regulatory status of cancer claims. In 2017 the US FDA told a soursop seller its capsules, tea bags and leaves were unapproved new drugs because of cancer and other … |
| Greater celandine | Skin and latex irritation. The fresh plant can cause acute toxicity because of the latex, and one woman developed severe itching, redness and bumps after us… |
| Green coffee bean | Caffeine effects. Because the beans contain caffeine, products can cause sleeplessness, nervousness, stomach upset, headache, fast or irregular hea… |
| Green coffee bean | Conditions needing caution. The same reference advises caution with high homocysteine, anxiety, bleeding disorders, diabetes, diarrhea or IBS, glaucoma, high… |
| Ground elder (goutweed) | Possible skin and sun sensitivity (not established). Furanocoumarins (angelicin, apterin) are listed in the plant; furanocoumarins in some related plants affect skin. The review does… |
| Ground elder (goutweed) | Possible add-on effect with metformin (animal data). In rats, the tincture partly enhanced low-dose metformin. Human interactions are unknown. |
| Guduchi (giloy) | Single case in a person with Hashimoto thyroiditis. A woman with Hashimoto thyroiditis developed liver injury after starting a supplement containing guduchi. Liver enzymes fell afte… |
| Guggul | Lowers blood levels of propranolol and diltiazem. In a small single-dose study in healthy men, gugulipid significantly lowered blood levels of the heart medicines propranolol and … |
| He shou wu | Onset and pattern of the injury. In the case series, symptoms began a median of 27 days after starting (range 1 to 120 days), mostly as hepatocellular injury with… |
| He shou wu | Genetic susceptibility (HLA-B*35:01). In Han Chinese patients, carrying the HLA-B*35:01 gene variant was strongly linked to liver injury from this root. Most people ar… |
| Heartsease (wild pansy) | Red blood cell breakdown in G6PD deficiency. The EU monograph reports one case of haemolysis (red blood cell breakdown) in a child with G6PD deficiency after taking the herb … |
| Heartsease (wild pansy) | Skin-use limits and missing safety tests. The skin forms should not be used on open wounds or large areas of damaged skin, and hot baths are not advised during fever or in… |
| Honeybush | Documented risk: none reported for tea, but little studied. A 2007 review found no adverse effects reported for honeybush tea, and the 12-week skin trial reported none. Human safety researc… |
| Honeysuckle (Lonicera) | Berries and leaves are irritating if eaten. An Australian government fact sheet says the berries and leaves of Japanese honeysuckle can cause stomach irritation and the plan… |
| Honeysuckle (Lonicera) | Traditional caution for weak digestion. Chinese medicine does not use the flower for people with weak digestion and loose stools. |
| Hoodia | Trade controls and misleading-claims warning. MSK says the FDA warned a hoodia maker and sellers about unsubstantiated weight-loss claims. Environment Canada (2008, trade pres… |
| Hops | Age limit and when to see a doctor. The EMA summary says hop products are for adults and adolescents over 12, and to consult a doctor or qualified practitioner if sy… |
| Horny goat weed | Skin vasculitis case report. A vasculitic rash occurred in a 77-year-old cancer survivor taking ginkgo and/or horny goat weed; it resolved after stopping. |
| Horse chestnut | Short-term safety of standardized extract. Standardized seed extracts are likely safe for short-term use and were used safely in studies of up to 12 weeks. |
| Horseradish | Safety data are thin. The sources we read do not describe thyroid, stomach, pregnancy, breastfeeding, child, liver, kidney, allergy, surgery or drug-in… |
| Horsetail | Thiaminase: destroys thiamine (vitamin B1). Raw and dried horsetail contains thiaminase, an enzyme that breaks down thiamine. Health Canada requires makers to show their pro… |
| Houttuynia (yu xing cao) | Hospital use of the injection halted in China (2006). Severe reactions in four children, two fatal, led China's drug regulator to halt hospital use in 2006. Some hospitals later banne… |
| Hydrangea root | Large-amount oral safety. A consumer drug reference rates large oral amounts as possibly unsafe, with dizziness, chest tightness and stomach or gut irritat… |
| Hyssop | Essential oil and seizure risk. e-lactancia describes hyssop essential oil as toxic to the nervous system and linked to seizures, and advises avoiding it. A 1999… |
| Hyssop | Plant chemistry varies between products. The genus review says the chemical make-up of extracts varies with growing place, weather, chemical type and extraction method, s… |
| Iceland moss | Radioactive caesium and other radionuclides. Iceland moss has been found to accumulate radioactive substances from nuclear tests and from Chernobyl fallout, and Scandinavian … |
| Irish moss (sea moss) | Iodine excess and the thyroid. Irish moss is a seaweed and contains iodine. Too much iodine from seaweed-type supplements can cause thyroid problems, and the am… |
| Irish moss (sea moss) | Bacteria in sea moss products. In 66 sea moss products bought online, bacteria such as presumptive Bacillus and Staphylococcus were found in dried products and … |
| Jamun (Java plum seed) | Long-term safety. The meta-analysis authors say current evidence does not support long-term safety. |
| Japanese knotweed (hu zhang) | Risk: invasive plant and wild harvesting. Japanese knotweed is considered invasive in the US and many European countries and appears on the EU list of invasive alien speci… |
| Jatamansi | Critically endangered wild plant; trade controls. The species is listed as Critically Endangered (IUCN, as cited in 2025) and is in CITES Appendix II because its rhizome is heavil… |
| Jiaogulan | Low platelet count (thrombocytopenia): one case report. A 2025 case report describes a patient whose platelet count fell to 6.0 x 10^9/L after more than three months of use and rose to … |
| Job's tears (coix seed) | Mold toxins in the seed. A 2026 study found the mold toxin zearalenone in every coix sample tested, higher in husk-and-bran mixes than polished seeds, and… |
| Job's tears (coix seed) | Mercury accumulation. A 2026 study found methylmercury built up in coix grain, with about half of samples above a concentration factor of 1; calculated… |
| Juniper Berry | Not for people told to limit fluids. Because adequate fluid intake is required with this use, it is not recommended where a doctor has advised reduced fluid intake. |
| Juniper Berry | Gaps in safety testing. No adequate tests on reproductive toxicity, and no tests on genotoxicity or carcinogenicity, have been done. |
| Kantakari (yellow-berried nightshade) | Solasodine effects on red blood cells (lab). A laboratory study reported solasodine triggers a form of red-blood-cell death (eryptosis). |
| Kava | Sedation and combining with alcohol or sedatives. Kava can make you drowsy and slow reactions. NCCIH and MSK advise against combining it with alcohol, benzodiazepines or other sed… |
| Kelp | Thyroid disturbance from excess iodine. Too much iodine from kelp can cause an underactive or an overactive thyroid. A case report describes a temporary overactive thyro… |
| Kelp | Iodine limits and who is more vulnerable. The American Thyroid Association advises against kelp or iodine supplements above 500 micrograms of iodine a day, and names infan… |
| Kelp | Unreliable product labelling. Labels often did not name the seaweed or gave iodine values that differed from lab results by more than 50%. |
| Khat | Dependence. The DEA says khat can lead to psychological dependence; reported after-effects include poor concentration, numbness and insomnia. |
| Khat | Mental-health harm (mania, psychosis, depression). The DEA lists manic behaviour, delusions, violence, suicidal depression and paranoid psychosis with chronic use. A critical revie… |
| Kola nut | Sleep problems, restlessness and over-excitability. Sleep disorders, over-excitability and nervous restlessness are listed as possible effects. |
| Kola nut | Cancer-related concerns with heavy chewing. The EMA report notes more mouth and digestive-tract tumours in Northern Nigeria where kola chewing is common, and lab concerns ab… |
| Kola nut | Safe long-term intake not defined. A 2009 food-safety review found kola extract probably acts like a similar amount of caffeine and that a no-effect level for repea… |
| Korean mint (huo xiang) | Estragole content and cancer-risk concern. One study found a Korean mint oil was about 89% estragole. A draft EU statement calls estragole a genotoxic carcinogen in animal … |
| Kratom | Dependence and withdrawal. Regular use can lead to tolerance, cravings and withdrawal. NIDA describes mild to moderate withdrawal after stopping regular use… |
| Kratom | Seizures. FDA names seizures in its warning. A 2026 systematic review found 20 reported patients, but only one had a lab-confirmed kratom m… |
| Kratom | Breathing and lung effects. NIDA says kratom leaf and mitragynine generally do not seem to cause the breathing suppression typical of opioid overdose, but 7-… |
| Kutaja (kurchi) | Pain and harm reported in an early alkaloid trial. An early trial of the plant's total alkaloids in amoebic hepatitis reported severe pain and no improvement. |
| Kutki | Endangered plant and wild-harvest pressure. Reviews describe kutki as endangered through over-harvesting, habitat loss and slow growth. A general encyclopedia entry reports … |
| Lavender | Driving and machines. The EU monograph says lavender flower medicines may impair the ability to drive and use machines. |
| Lemon balm | See a doctor if symptoms last. The EU summary advises seeing a doctor if symptoms persist after 2 weeks of use. |
| Licorice root | Who is more sensitive. Larger effects are reported in people who eat a lot of salt and in people with high blood pressure, heart or kidney conditions or… |
| Lily bulb (bai he) | Sulfur fumigation of dried bulbs. Sulfur smoke is used to preserve lily bulbs; heavy fumigation raised sulfur-containing derivatives and lowered antioxidant activi… |
| Lily bulb (bai he) | Look-alike: peace lily is a different plant. Peace lily (Spathiphyllum, Araceae) is a houseplant toxic to cats and dogs through calcium oxalates; it is not the medicinal lily… |
| Lily of the valley | Nervous system and vision effects. Confusion, drowsiness, headache, weakness, blurred vision and halos around lights can occur. |
| Lily of the valley | Mix-up with wild garlic and autumn crocus. Leaves can look like wild garlic (ramsons) before and after flowering, and mix-ups have caused poisonings. Autumn crocus is a dif… |
| Lily of the valley | Vase water and confusion. A poison-center article mentions a confused older woman who drank water from a vase of lily of the valley. |
| Lily of the valley | Antidote question. ACMT says digoxin-specific Fab is the antidote for significant heart-active plant poisoning; a 2014 laboratory study found Fab di… |
| Lion's tail (wild dagga) | Blood-count and blood-chemistry changes in rats. Water extracts changed blood cell counts and blood-test markers in rats; at the highest acute dose in one study some rats died. |
| Lobelia | Use with nicotine products. MSK advises against taking lobelia with nicotine products because effects can add up and cause toxicity. |
| Lobelia | Smoking cessation. No good evidence that lobelia or lobeline helps people quit smoking. The FDA removed over-the-counter smoking-cessation products … |
| Lodhra | Look-alike barks sold as lodhra. A plant database says the bark of Symplocos crataegoides and of Symplocos cochinchinensis subspecies laurina is used in place of … |
| Long pepper | Monitoring with phenytoin. A 2025 systematic review suggests that piperine used with the seizure medicine phenytoin should be monitored because absorption a… |
| Long pepper | Reproductive and embryo effects of isolated piperine (animals). In animal studies using higher daily piperine bolus doses than in human interaction studies, German risk assessors saw signs of d… |
| Lungwort | DNA damage in human lung cells at higher extract levels. In a 2025 cell study, higher concentrations of an alcohol extract caused DNA damage in human lung fibroblasts, while very low lev… |
| Maca | Safety not yet proven in menopause trials. The menopause systematic review said safety has not been proved and called for larger studies. Pregnancy, breastfeeding, children… |
| Magnolia flower bud (xin yi) | Variation between the three official source species. The Chinese Pharmacopoeia lists three source species. In one study of buds from one province, bud-oil 1,8-cineole met the standar… |
| Malkangani (intellect tree) | Wild harvest and conservation. Seeds are collected from wild plants. One regional page lists Vulnerable in two central Indian states with declining trade; anoth… |
| Mangosteen | Possible added immune suppression with cyclosporine or tacrolimus. MSK lists calcineurin inhibitors as a possible additive immunosuppression concern. |
| Mangosteen | Possible interference with chemotherapy and radiation. MSK says antioxidant effects may interfere with cancer treatment, naming anthracyclines, platinum compounds and alkylating agents. |
| Mangosteen | Lactic acidosis case report. MSK describes one case of severe lactic acidosis after daily mangosteen juice for 12 months. |
| Manjistha | Madder (Rubia tinctorum) regulatory warning and name confusion. The review reports that the European Commission considers Rubia tinctorum a plant with serious risks (genotoxic and cancer potent… |
| Mayapple | Absorption through skin and eyes. The resin is absorbed through skin, especially broken skin, and can cause serious whole-body poisoning after skin use, with sympt… |
| Mayapple | Nerve damage. IPCS reports nerve damage that can appear about two weeks after exposure, can worsen for months and can be permanent. |
| Mayapple | Mistaken identity (mandrake). IPCS also calls the plant mandrake, a name used for other plants; check the Latin name on any label. |
| Meadowsweet | Salicylate hypersensitivity (contraindication). The EU monograph lists hypersensitivity to salicylates as a reason not to use meadowsweet, because the plant contains salicylate-… |
| Mistletoe (European) | Possible interference with cancer treatment. NCI advises talking to your doctor first because mistletoe may interfere with standard treatment or be harmful alongside it. |
| Monk fruit | Incomplete safety data: EFSA 2019 opinion. EFSA said the toxicity data were not enough to conclude a monk fruit extract is safe as a food additive. It cited testis changes … |
| Monk fruit | Possible male reproductive effects (animal). In rats, a 90-day study of a 52% mogroside V extract showed lower testis weight and tubule degeneration at the highest dose. A re… |
| Monk fruit | Regulators disagree across countries. FDA and Health Canada accept purified extracts under set conditions; EFSA could not conclude safety. Health Canada proposed limit… |
| Moringa | Product standardization. A 2015 review says moringa products are not standardized and calls for studies using standardized extracts, so results for one pr… |
| Motherwort | Risk: may affect driving and machines. The European monograph, as summarised on our page, says motherwort may impair the ability to drive and use machines. |
| Motherwort | Duration of use. The European summary says to see a doctor if symptoms last longer than 4 weeks or get worse. |
| Moutan (tree peony root bark, mu dan pi) | G6PD deficiency (laboratory finding). A laboratory (in vitro) study cited by the Hong Kong database found a pro-oxidative effect on red blood cells from people with G6… |
| Mucuna pruriens (velvet bean) | Psychiatric effects, dopamine dysregulation and overuse. Hallucinations, paranoia, psychosis and compulsive overuse have been reported with Mucuna levodopa supplements in a person with P… |
| Mucuna pruriens (velvet bean) | Product variability, wrong species and legal status. Levodopa content in supplements ranged from a fraction of the label to many times more. Other Mucuna species also contain levodop… |
| Mucuna pruriens (velvet bean) | Itching from pod hairs. Cowhage-type pods carry hairs that cause intense itching and dermatitis; soft-haired types do not. |
| Mugwort | Celery-mugwort-spice cross-reactions. People allergic to mugwort pollen may react to celery and some spices, and a severe reaction was reported in a case report. |
| Mugwort | Possible DNA damage in laboratory tests. A 2020 laboratory study reported that mugwort extracts raised signs of chromosome damage in human blood cells at higher concentra… |
| Mullein | Persistent or worsening symptoms need a clinician. The EU monograph advises seeing a doctor if symptoms last over a week, worsen, or come with breathlessness, fever or pus-coloured… |
| Notopterygium (qiang huo) | Sun sensitivity not studied. The root contains furanocoumarins, a compound family that includes sun-sensitising members in other plants. The qiang huo sources… |
| Notopterygium (qiang huo) | Endangered wild plants. Researchers describe Notopterygium incisum as endangered and both medicinal species as protected in China; wild collection faces … |
| Oat straw (milky oats) | Gluten cross-contact in oat products. Oats have no gluten of their own but are often exposed to wheat, barley and rye. A few people with coeliac disease react even to … |
| Oleander | Leaf tea mistaken for a safe plant. An 84-year-old man drank an oleander leaf infusion believing it was bay laurel and developed third-degree heart block. |
| Oleander | Plant mix-ups with food plants. In a 22-year French poison-center review, oleander was the plant most often involved in food-confusion cases (289 of 2,197). |
| Oleander | Smoke from burning clippings (animal report). 76 of 205 beef cattle died after oleander clippings were burned near their housing; oleandrin was found in tissues. |
| Oleander | Yellow oleander in supplements. A different plant, yellow oleander, has been found in weight-loss and other supplements, including a product labelled tejocote ro… |
| Olive leaf | Tolerability in trials. The 621-person trial reported no significant adverse events and the ESOLED pilot reported none serious. The EU regulator had rece… |
| Ophiopogon (mai dong) | Look-alike root (Liriope) in the supply chain. A 2025 DNA study found about 88% of 162 samples were genuine ophiopogon; 16 were Liriope and 2 another Liriope species. The two r… |
| Oregon grape | Skin irritation from creams. In the placebo-controlled trial, side effects were infrequent and minor: rash, burning on application and clothing stains. |
| Osha | Deadly look-alike plants (hemlock). Osha is easily confused with poison hemlock and other toxic carrot-family plants; less than 0.1 g of poison hemlock can be deadly… |
| Osha | Wild-harvest and conservation concern. United Plant Savers gives osha an at-risk score of 48; it is hard to grow so most supply is wild, and informal reports say small … |
| Osha | Safety not established in several groups. An encyclopedia article says safety has not been established for young children, nursing women, or people with severe liver or ki… |
| Osha | Mouth irritation from fresh root. Fresh root is very astringent and can blister the mouth and mucous membranes; dried root is not. |
| Papaya leaf | Dengue needs medical care (official guidance). CDC and WHO say there is no specific antiviral treatment, advise supportive care, avoiding aspirin and ibuprofen, and getting urg… |
| Pau d'arco | Anemia and reproductive effects in animals. Large long-term lapachol doses caused anemia in animals and short-term lapachol reduced seminal vesicle weight in mice. Human rel… |
| Pelargonium (Umckaloabo) | Age limits. The EU public summary says use is for people aged 6 years and older, and to see a doctor if symptoms last more than 1 week or get… |
| Perilla (shiso) | Perillaldehyde safety questions. Perillaldehyde holds GRAS status but animal studies suggested liver toxicity at higher exposures. |
| Phellodendron | G6PD deficiency and haemolytic disease. Singapore's regulator advises avoiding berberine at any age in G6PD deficiency, and a review advises bilirubin and haemoglobin mo… |
| Pine pollen | Cross-reactivity with pine nuts (documented risk). A case report found antibodies that react with both pine nut and pine pollen proteins, so sensitisation to both is possible. |
| Pipsissewa | No human safety data. No human safety study, interaction study or regulator safety statement was found. Absence of reports is not proof of safety. |
| Pipsissewa | Cautions known for the related plant uva ursi. For uva ursi, EU sources advise against use with kidney disorders, in pregnancy and breastfeeding, and under 18. Whether this app… |
| Pipsissewa | Threatened conservation status of wild plants. The 2023 review describes the species as having a threatened conservation status, so wild picking can harm populations. |
| Plantain herb | Safety record is thin. For broadleaf plantain we found no regulator monograph and no source on medicine interactions, pregnancy, children, liver or kidn… |
| Plantain herb | Wounds need proper care. The trials used lab-made products alongside routine wound care. Deep, dirty, infected or slow-healing wounds, and any wound in a … |
| Platycodon (balloon flower) | Hemolysis (red blood cell damage) from saponins. A 2023 review says platycodin D can cause hemolysis and calls this a safety concern that limits clinical use; oleanane-type sapon… |
| Pleurisy root | Eye injury from handling the plant. A 2026 case report describes a gardener who lost vision and had clouded corneas after handling Asclepias tuberosa with contact le… |
| Poison hemlock | Breathing failure. Paralysis of the breathing muscles can be fatal; one reported patient needed a breathing tube and intensive care. |
| Poison hemlock | Mistaken for wild carrot, parsnip and other plants. The poison center lists Queen Anne's lace (wild carrot), wild parsnip, elderberry and water hemlock as look-alikes; severe poison… |
| Poison hemlock | Severity depends on amount eaten. Two people who shared a meal had very different outcomes, from intensive care to mild symptoms; the authors suggest the amount ea… |
| Poison hemlock | Skin irritation and smoke. Skin contact can irritate. The poison center advises rinsing with lukewarm water and, if smoke from burning the plant is breathed… |
| Poke root (pokeweed) | Skin contact. Juice can be absorbed through bare skin. The Kentucky review reports swelling, pain and edema after skin exposure. |
| Poke root (pokeweed) | Mitogen and saponin toxins. Memorial Sloan Kettering names mitogens (substances that push certain white blood cells to multiply) and saponins as known toxins… |
| Polygala (yuan zhi) | Throat irritation. A toxicology review says clinical practice shows the root can irritate the throat. |
| Polygonatum (huang jing, Solomon's seal) | Look-alike names (Polygonum multiflorum / he shou wu). Polygonatum is a different genus from Polygonum multiflorum (he shou wu, fo-ti), which is known for liver-injury reports. Liver i… |
| Prickly ash (northern) | Safety not established by modern testing. Reviews say it has had no modern safety evaluation and contains alkaloids that may be toxic; harm is unknown. |
| Prickly pear (nopal) | Botulism from home-canned nopales. A 2024 California outbreak affected 8 of 31 guests who ate a salad of home-canned nopales; 6 went to intensive care and all survi… |
| Prickly pear (nopal) | Skin irritation from spines and glochids. Spines and tiny hairs can embed in skin and cause local inflammation and allergic contact dermatitis. |
| Pueraria mirifica (kwao krua) | Transient lab abnormalities in small human studies. Some women in the small Thai studies had short-lived abnormal liver, blood-count or kidney results. |
| Pumpkin seed | Delay in seeing a doctor for urinary symptoms. The monograph says to see a doctor if symptoms worsen or if fever, spasms, blood in the urine, painful urination or being unable … |
| Pygeum | See a doctor first; symptoms can have serious causes. Fever, spasms, blood in the urine, painful urination or urinary retention, or worsening symptoms, need a doctor. The EU monograph… |
| Pygeum | Conservation of the tree. Prunus africana is listed in CITES Appendix II owing to overexploitation, so the source of bark matters. |
| Red clover | Long-term safety. Extracts were used in studies of up to 2 years with apparent safety, but Memorial Sloan Kettering says long-term safety is not kn… |
| Red root | Possible effect on blood clotting (caution). Animal research suggests root fractions may shorten clotting time. One consumer reference says the effect may reverse at higher c… |
| Red root | Tannins, digestion and iron absorption. The root is rich in tannins (about 8 percent per a plant database). A consumer reference says high intake may upset the stomach o… |
| Restharrow | Incomplete safety testing. The EMA says adequate genotoxicity tests were not done; one test-tube study of an unnamed Ononis species showed chromosome-damage… |
| Rhaponticum (maral root) | Sport anti-doping question. The authors of the 2019 trial argued ecdysterone should be on the prohibited list in sport. Athletes should check current anti-do… |
| Rhaponticum (maral root) | Label does not match contents. In a 2025 trial a commercial phytosteroid capsule held under 1% of its claimed 20-hydroxyecdysone. |
| Rhubarb root | Risk: long-term laxative use, dependence and colon lining changes. Long-term use may cause dependence, salt and water imbalance, protein or blood in the urine and discolouration of the colon linin… |
| Rooibos | Possible interference with chemotherapy. MSK says rooibos's antioxidant effects may interfere with certain chemotherapy drugs. |
| Rose petals | Gaps in safety testing. The EU monograph states that tests of genotoxicity, reproductive toxicity and cancer risk have not been done. It reports no inter… |
| Rue | Organ injury from coumarin compounds (mechanism unclear). A 2023 emergency-medicine review says organ injury from rue is suspected to come from coumarin compounds such as chalepesin, but … |
| Rue | Skin irritation from volatile oils. The Hong Kong atlas says skin contact with rue can cause irritant contact dermatitis, and lists volatile oils among its constitue… |
| Rue | Not used as an insect repellent. A dermatology case report concluded that rue should not be used as an insect repellent because of its photoirritant reaction. |
| Safed musli | Over-collection and endangered wild stock. The review calls the plant endangered because of commercial exploitation and low productivity and recommends cultivation. |
| Sage | Thujone: seizure risk at high amounts. Common sage contains thujone, which can be toxic in large amounts. Sage oil equal to more than 15 g of leaf has been reported to … |
| Sandalwood | Fake and mixed sandalwood oils. In a 2021 test of six commercial oils sold as sandalwood, none met the international standard; one matched Santalum album, three … |
| Saposhnikovia (fang feng) | Sun sensitivity risk (furanocoumarins in the plant family). Many plants in the carrot family (Apiaceae) contain furanocoumarins that react with UVA light on skin. A 2025 study identified im… |
| Saposhnikovia (fang feng) | Counterfeit and look-alike roots. A 2025 paper describes Libanotis laticalycina root as the more common counterfeit of fang feng and says it is thought to be more … |
| Saposhnikovia (fang feng) | Thin side-effect data in formula trials. In the asthma review only 2 of 20 trials reported side effects (mild stomach upset, dry mouth); in the rhinitis review 15 of 39 t… |
| Saptaparna (devil's tree) | Birth abnormalities in mice given bark extract (secondhand). A paper on leaf alkaloids cites earlier mouse studies in which a bark extract caused congenital abnormalities. Original studies w… |
| Sarpagandha (Indian snakeroot) | Mood effects: depression warning and unsettled evidence. The US label warns that reserpine can cause depression and lists a history of depression as a contraindication. A 2023 review of … |
| Sarpagandha (Indian snakeroot) | Hidden reserpine in herbal products. A case report describes parkinsonism and depression from a herbal medicine containing reserpine, recognized late. Another report … |
| Sarpagandha (Indian snakeroot) | Cancer questions. High-dose reserpine caused tumors in rodents per the label. A 2002 review said early human studies linked reserpine to breast can… |
| Sarpagandha (Indian snakeroot) | Wild population under threat. A 2025 Nepal study described the plant as threatened by unsustainable harvest, habitat loss and an invasive weed. |
| Sarpagandha (Indian snakeroot) | Look-alike snakeroot plants. Virginia snakeroot (Aristolochia serpentaria) and Canada snakeroot (Asarum canadense) are on an FDA import alert for aristolochic… |
| Sarsaparilla | Root dust and mix-ups with look-alike plants. Root dust can cause a runny nose and asthma-like symptoms; false sarsaparilla (Hemidesmus indicus) may appear in products. |
| Sassafras | US food ban on safrole and oil of sassafras. Since 1960 the US has banned adding safrole or oil of sassafras to food; food made from sassafras bark mainly to flavor other foo… |
| Sassafras | Risk rises with amount and duration of use. MSK says the cancer risk goes up with the amount of sassafras used and for how long, and advises against using it or its oil to t… |
| Sassafras | Safrole content varies hugely between sassafras products. In a 1997 lab test of 26 products, most leaf samples had safrole below detection, one oil had up to 92.4 percent, and brewed root… |
| Sassafras | Hot flashes and heavy sweating. MSK lists hot flashes and profuse sweating as adverse effects, with a case report after drinking sassafras tea. |
| Sassafras | Safrole-free extract allowed as food flavoring. US rules allow a water-based extract of sassafras root bark as a flavoring only if the final extract is free of safrole after a s… |
| Sausage tree (kigelia) | Fall in white blood cells in a rat study of a mixture. A 30-day rat study of a herbal mixture containing Kigelia showed dose-related lower white blood cell counts. |
| Sausage tree (kigelia) | Products are often not standardised. The review says commercial Kigelia products are often not fully standardised, so strength and content may vary. |
| Saw palmetto | Radiation therapy caution. A lab study found an extract slowed normal prostate cells and made them more sensitive to radiation; MSK advises talking to a phy… |
| Schisandra | Tacrolimus blood levels. A meta-analysis of 11 studies found a capsule made from the related species Schisandra sphenanthera (Wuzhi) raised blood tacrolim… |
| Sea buckthorn | Safety: changes in blood phosphate, sodium and iron in dialysis patients. In the dialysis trial, plasma phosphate and sodium rose and iron fell with oil capsules. People with kidney disease should ask th… |
| Senna | Dependence and poor bowel function with long use. The EU committee warns that longer use may lead to the bowels not working properly and to laxative dependence. |
| Senna | Not suitable with some bowel conditions. Senna should not be used with intestinal blockage, appendicitis, inflammatory bowel disease, unexplained belly pain or severe deh… |
| Shankhpushpi | Identity confusion: several plants sold as shankhpushpi. At least four different plants (Convolvulus pluricaulis, Evolvulus alsinoides, Clitoria ternatea, Canscora decussata) are used or… |
| Shepherd's purse | Not recommended under 18. The EU monograph does not recommend use in adolescents under 18 and limits the medicine to adult women. |
| Sophora flavescens (ku shen) | Possible nervous-system effects of matrine. In mice, matrine caused brain changes and poorer balance and coordination; it also harmed nerve-like cells in the laboratory. No … |
| Sophora flavescens (ku shen) | Possible reduced sperm function. Matrine reduced sperm function in mice and in sperm cells in the laboratory. Human data were not found. |
| Spirulina | Vitamin B12 source (a common myth). Most B12 in spirulina powders was pseudovitamin B12, not the active form; absorption in people was not tested. |
| St. John's wort | Reduced effect of birth control pills. It can make the contraceptive pill less effective. |
| Stinging nettle | Possible reduction of iron effect (tannins). NCCIH notes a 2015 review saying nettle contains tannins that can interact with iron and may reduce its effect in people needing … |
| Suma (Brazilian ginseng) | Product content and labeling varies. A 2025 trial found a commercial ecdysterone product held under 1% of the labeled amount. A sports-nutrition article warns content… |
| Sundew | Wild harvest and conservation of bog populations. Sundew grows in peat bogs. United Plant Savers lists it as Critical and advises against wild harvest; a 2024 study says its medic… |
| Sweet violet | Vomiting and purging from roots and seeds. A plant database says the roots contain violine, strongly emetic and purgative at higher amounts, and the seeds are purgative. |
| Sweet violet | Possible added effect with laxatives. The plant database lists a possible additive effect with laxatives. |
| Sweet violet | Salicylic acid content. Salicylic acid is reported in all parts except the rhizome, so people who must avoid aspirin-type substances should ask a pharmac… |
| Sweet violet | Look-alike: wild pansy is a different plant. Sweet violet (Viola odorata) is not wild pansy or heartsease (Viola tricolor), which has an EU traditional-use monograph for skin… |
| Sweet woodruff | Daily coumarin limit and home-made syrups. BfR and AGES use a tolerable daily intake of 0.1 mg per kg body weight. AGES warns that strong home-made woodruff syrup can excee… |
| Sweet wormwood (Artemisia annua) | Accelerating artemisinin resistance. WHO says widespread use of Artemisia herbal remedies could speed up the development and spread of artemisinin resistance. |
| Tagara (Indian valerian) | Wrong plant sold as tagara. In a 2023 study of five tagara samples bought in Kerala markets, none matched the official Valeriana jatamansi rhizome; they rese… |
| Tansy | Seizure risk. Tansy oil can cause convulsions, according to the thujone monograph; the consumer reference lists seizures and tremors. |
| Tansy | US food rule. In the US, tansy is permitted only in alcoholic drinks that are thujone free. |
| Tepezcohuite | Birth defects and miscarriage risk (animals). The plant is a proven cause of abortion and malformations in sheep, goats and cattle in Brazil, and of cleft palate and bone defe… |
| Thunder god vine | Immune suppression and low white blood cells. NCCIH lists lower white blood cell counts as a side effect; a 2026 review describes immunosuppression. |
| Tribulus | Doping-test concerns for athletes. In two small studies, short-term tribulus did not push urinary steroid markers over anti-doping cut-offs. Products may contain ot… |
| Trichosanthes (tian hua fen) | Brain, nerve and muscle effects of injected trichosanthin. In early HIV trials of purified injected trichosanthin, some people had confusion, dementia or coma (described as reversible), mu… |
| Trichosanthes (tian hua fen) | Reactions to the raw prescription. The raw Tian Hua Fen prescription caused fever, skin eruptions and abdominal pain, which led to a purified form being developed. … |
| Trichosanthes (tian hua fen) | Look-alike species and plant part. Other Gua Lou species cause more nausea and vomiting than the species that makes trichosanthin. The root and the fruit are differ… |
| Uncaria (gou teng) | Look-alike species: cat's claw. Gou teng is often confused with Uncaria tomentosa (cat's claw). A 2026 case report of a woman who used and then stopped a high-do… |
| Uva Ursi | Not recommended for men or for under-18s. The monograph does not recommend use in men or in children and adolescents under 18, citing concerns that need medical advice or … |
| Uva Ursi | Short-term use only; see a doctor if symptoms worsen. The traditional-use monograph says the product should not be used for more than one week, and a doctor should be consulted if sym… |
| Valerian | Sedation with alcohol or sedatives. Valerian may have a sleep-inducing effect and should not be combined with alcohol or sedatives. |
| Valerian | Withdrawal after long use. After chronic use, stopping valerian suddenly may cause anxiety, irritability, heart disturbances and insomnia, and rarely halluc… |
| Vasaka (Malabar nut) | Womb stimulation and abortifacient effect. Reviews report that vasicine stimulates womb muscle and can end pregnancy in animals, and the plant is used traditionally to end … |
| White kidney bean extract | Safety of the extract in trials. The 2026 meta-analysis reported no serious adverse events related to the extract and one 45-day trial reported none; reviewers no… |
| White sage | Smoke particles and breathing. Burning plant material releases fine particles. Health Canada lists candle and incense smoke as indoor sources and says fine part… |
| White sage | Reported lung disease after regular burning of sage and oils. A 2025 case report describes a never-smoker with a type of interstitial lung disease who made fires burning sage and oils; she im… |
| White sage | Wild-harvest, poaching and conservation concern. Reports describe large-scale poaching of wild white sage in Southern California and habitat loss. It is on United Plant Savers' t… |
| White sage | Aromatic oil with 1,8-cineole and some camphor. The leaf's essential oil includes 1,8-cineole and some camphor, and no thujone was detected in the samples tested. These come fro… |
| Wild cherry bark | Cyanide release from the plant (documented risk). Wild cherry contains prunasin, which releases hydrogen cyanide when the plant is crushed, chewed or digested. Too much can cause … |
| Wild cherry bark | Wilted leaves, twigs and seeds are especially hazardous. A university page names wilting leaves as the most dangerous part, with green leaves, twigs, bark and seeds also toxic; livestock… |
| Wild ginger (Canadian) | Aristolochic acid content varies between samples. Levels in A. canadense rhizome varied widely, reaching about 0.037 percent of dry weight in one survey. A 2017 study found high a… |
| Wild ginger (Canadian) | US import alert covers Asarum canadense. FDA Import Alert 54-10 (December 2020) allows detention of supplements, drugs and other products made wholly or partly from liste… |
| Wild ginger (Canadian) | Essential oil rich in methyleugenol. Reviews report the rhizome oil is largely methyleugenol (about 36 to 54 percent in some samples). A 2023 review says some alkenyl… |
| Wild lettuce | Anticholinergic-type effects (hyoscyamine traces). The case-report authors say traces of hyoscyamine are probably responsible for sedative effects; patients had dry mouth, dilated … |
| Wild lettuce | Skin irritation from fresh latex. Fresh plant latex may irritate skin. |
| Witch hazel | Eye irritation and conjunctivitis. Cases of conjunctivitis have been reported with eye drops containing witch hazel distillate. The EU monograph says to stop and as… |
| Witch hazel | Tannins may reduce absorption of minerals and B vitamins. The EMA report states that tannins inhibit absorption of minerals and B vitamins, which matters mainly for oral tannin-rich produ… |
| Wood betony | Lab DNA-damage tests of extracts. In a 2019 cell study, extracts of Betonica officinalis were not mutagenic in the Ames test or chromosome-damaging, but showed DNA… |
| Wormwood | Absinthe, alcohol and legal limits. Drinks made from Artemisia species may contain up to 35 mg thujone per kg in the EU. In the US, spirits may be labelled absinthe … |
| Wormwood | Not the same as sweet wormwood (Artemisia annua). Sweet wormwood is a different species, source of the malaria medicine artemisinin. MSK warns not to confuse it with absinthe worm… |
| Yellow dock | Low platelets (thrombocytopenia) case report. One case report describes a woman whose platelet count fell to 5 K/ul a week after drinking a tea containing yellow dock and burd… |
| Yerba mansa | Urinary tract irritation. A consumer drug reference says it can irritate the urinary tract and advises against use with urinary disorders. |
| Yerba mansa | Wild-plant and wetland-habitat conservation. The plant needs wet ground that has shrunk; United Plant Savers rates it At-Risk and recommends cultivated sources. |
| Yerba mate | Very hot drinking and esophageal cancer. IARC found that very hot drinks (above 65 C), including traditionally hot mate, probably cause esophageal cancer; mate drunk warm… |
| Yerba santa | Safety of medicinal amounts is not established. A consumer drug reference says there is not enough reliable information to know whether larger, medicinal amounts are safe by mou… |
| Yohimbe | Anxiety, nervousness and mood effects. MSK lists anxiety, nervousness, insomnia and manic symptoms; Health Canada lists anxiety as one of the most consistently reported… |
| Yohimbe | Unreliable content and label accuracy. In a 2016 test of 49 US products, yohimbine ranged from none detected to 12.1 mg per serving; only 11 listed an amount and most w… |
Some herbs change how a medicine works, or add to its effect. This matters most for narrow-margin medicines such as blood thinners, antidepressants, immunosuppressants, and diabetes and blood pressure medicines. Always tell your pharmacist and clinician about every herb you take. Ask before starting, stopping or combining anything.
Herb-Drug Interactions: How They Happen · Medication interactions in Natural Remedy Safety
Each line comes from a herb's own guide and its cited sources. A herb missing from a list is not proven free of interactions: it may simply not have been studied. Open the herb's guide for the full wording.
| Herb | What its guide documents |
|---|---|
| Acai | Blood sugar and diabetes medicines. Early research suggests acai may raise or lower fasting blood sugar, so it could interfere with diabetes medicines. |
| African potato | Possible interaction with HIV medicines. In lab tests extracts inhibited drug-processing enzymes (CYP3A4 among them) and affected the P-glycoprotein transporter. Two smal… |
| African wormwood | Antibiotic interactions in test tubes. In a 2025 lab study an extract weakened the effect of several antibiotics, and one pairing was toxic to brine shrimp. |
| Agrimony | Limited safety data (side effects, interactions, toxicity tests). The monograph lists no known side effects and no reported interactions, but says tests on genotoxicity, carcinogenicity and repro… |
| Albizia (mimosa tree bark) | Added sedation with sleep medicines. A consumer drug reference lists a moderate interaction with sedating medicines (benzodiazepines, zolpidem, barbiturates). |
| Alfalfa | Warfarin and vitamin K. LactMed says alfalfa contains vitamin K and should be avoided with warfarin. MSK did not list a warfarin interaction, so sources … |
| Aloe vera | Heart medicine interaction (latex). Overuse of aloe latex may increase side effects of cardiac glycosides such as digoxin. |
| American ginseng | Possible effect on warfarin (reduces its action). In a small trial in healthy volunteers, American ginseng lowered warfarin levels and its effect on INR. Anyone on warfarin should… |
| American ginseng | Interaction with diabetes medicines. Because blood glucose may fall, people using diabetes medicines should ask a clinician before adding it. |
| American ginseng | Possible effect on other medicines (CYP3A4). Lab work suggests certain ginsenosides may induce the CYP3A4 enzyme and affect medicines cleared by it. Clinical relevance is not… |
| Amla | Possible blood-sugar-lowering with diabetes medicines. The trial authors suggested the extract may lower blood sugar. This is a reason to tell your prescriber, not a proven interaction. |
| Andrographis | Injectable andrographolide medicines carry a serious anaphylaxis risk. A review of 262 studies found life-threatening anaphylactic shock, including deaths, with injectable andrographolide derivative m… |
| Angelica dahurica (bai zhi) | Slowing of medicine clearance (rat data). In rats a water extract raised blood levels of tolbutamide (about 2.5 times exposure) and diazepam (about 4-fold peak), attribute… |
| Arjuna | Possible interactions with heart, blood pressure and blood-thinning medicines. WebMD says arjuna may add to or change the effects of heart, blood pressure, cholesterol, blood-thinning, heart-rhythm and chest-… |
| Arnica | Platelet inhibition and blood-thinner interaction. Arnica inhibited platelet clumping in the laboratory, and MSK warns it may increase the effect of warfarin and other blood thinne… |
| Artichoke leaf | Children and drug interactions. Use under 12 years is not recommended for lack of data. The monograph lists no reported interactions, which does not prove there … |
| Asafoetida (hing) | Lack of safety data (pregnancy, medicines, liver, kidney). We found no source we could read that covers pregnancy, breastfeeding, medicine interactions or liver and kidney safety. Absence … |
| Ashitaba | Bleeding risk, blood thinners and surgery. In rats, high doses lowered platelets and lengthened clotting times (prothrombin and APTT). EFSA did not assess medicine interact… |
| Ashwagandha | Medicine interactions and surgery (documented risk). NCCIH says it might interact with diabetes, blood pressure, immunosuppressant, sedative, anti-seizure and thyroid hormone medicin… |
| Asian ginseng | Blood sugar lowering: risk with diabetes medicines. Ginseng may lower blood sugar, so people with diabetes should talk with a provider first. MSK says it may increase low blood suga… |
| Asian ginseng | Blood thinners, clotting and surgery. Ginseng may interfere with blood clotting. Results with warfarin are mixed, and MSK suggests it may raise aspirin levels. MSK adv… |
| Astragalus | Interaction with immune-suppressing medicines. Astragalus may interact with medicines that suppress the immune system. Ask the prescriber; never stop a prescribed medicine on y… |
| Autumn crocus (colchicum) | Interactions with medicines. Colchicine toxicity can rise with some antibiotics (clarithromycin, erythromycin), antifungals, cyclosporine, protease inhibitors… |
| Bael | Possible low blood sugar with diabetes medicines (reasoned caution). Because bael is claimed to lower glucose, a diabetes patient should tell the prescriber. No source we read documents an actual in… |
| Bakuchi (babchi) | Possible medicine interactions (CYP3A4). A review lists psoralens as possibly interacting with medicines handled by the CYP3A4 enzyme. |
| Barberry | Medicine interactions through liver enzymes. Barberry and its berberine affect several enzymes that process medicines, especially CYP2D6 and CYP3A4, so some medicines could a… |
| Bee balm (Monarda) | Limited safety information and unknown medicine interactions. The same consumer reference says reliable safety and side-effect information for oral use is lacking and it is unknown whether be… |
| Belladonna (deadly nightshade) | Interaction with other anticholinergic medicines. A German reference says tricyclic antidepressants, amantadine and quinidine may increase belladonna's anticholinergic effect. |
| Berberine | Interactions with other medicines. Berberine can raise cyclosporine levels in kidney-transplant recipients, and may affect tacrolimus, liver-processed medicines and… |
| Bergamot | Cholesterol medicines and other interactions. Some trials combined bergamot with statins; a 2025 review says data on interactions are still lacking and suggests monitoring. A … |
| Betel nut (areca nut) | Medicine interactions. A consumer drug reference lists moderate interactions with anticholinergic medicines, cholinergic and Alzheimer's medicines, and … |
| Bibhitaki | Low blood sugar with diabetes medicines. Bibhitaki might lower blood sugar, so combining it with diabetes medicines or other blood-sugar-lowering herbs could push blood s… |
| Bibhitaki | Medicine interactions through liver enzymes (as part of triphala). MSK says triphala blocks the liver enzymes CYP3A4 and CYP2D6 and may raise levels of medicines those enzymes clear. |
| Bilberry | Possible blood-sugar lowering with diabetes medicines. Bilberry has been reported to lower blood glucose, so people who take diabetes medicines should ask a pharmacist or doctor first. |
| Bitter kola | Interaction with medicines (quinine reported, unverified). The 2026 survey notes earlier reports of an interaction with quinine sulfate, with the mechanism unverified, and lists antimalari… |
| Bitter leaf | Possible herb-drug interaction with diabetes medicines. In diabetic rats, a leaf extract changed how metformin was absorbed and cleared, and it blocked two liver enzymes in a lab test. … |
| Bitter Melon | Effect on blood sugar medicines. Because bitter melon can lower blood sugar, it may add to diabetes medicines; the sources we read did not describe specific inter… |
| Bitter orange | Medicine interactions and combined stimulants. NCCIH advises anyone taking medicines to talk to a health professional first. Products often add caffeine and other stimulants. A… |
| Black cohosh | Hormone-sensitive cancers and cancer medicines. Safety is uncertain for women with breast or uterine cancer. It may interfere with tamoxifen or add toxicity with some chemothera… |
| Black haw | Aspirin-allergy and asthma caution (salicylates). The bark contains salicylates, which might trigger reactions in people with asthma or aspirin allergy. |
| Black horehound | Interaction with dopamine-type Parkinson's medicines. RxList rates a moderate interaction: the herb may increase the effects and side effects of drugs such as levodopa, bromocriptine,… |
| Black seed | Medicine interactions (liver enzymes, warfarin). Black seed may inhibit the liver enzymes CYP2D6 and CYP3A4 and change levels of medicines cleared by them. Thymoquinone inhibited… |
| Bladderwrack | Interaction with lithium and thyroid medicines. The EU says bladderwrack should not be taken with iodine products or thyroid medicines, and lists lithium among possible interact… |
| Bladderwrack | Other medicine interactions (blood thinners, blood-pressure drugs, enzyme-handled drugs). The EU lists blood thinners and blood-pressure medicines as possible interactions (other literature considers an effect on vitami… |
| Blessed thistle | Possible interactions (stomach-acid medicines, bleeding). No interactions have been reported. EMA notes in theory it might weaken antacids and acid-reducing medicines, and that a lab plat… |
| Blue flag | Laxative-type medicine interactions (digoxin, warfarin, water pills). A consumer drug reference lists a major interaction with digoxin and moderate ones with warfarin and diuretics, because of laxati… |
| Boldo | Warfarin and tacrolimus case reports. The EMA found one case report of raised INR in a person taking warfarin with a boldo liquid plus fenugreek capsules, and one of l… |
| Boneset | Medicine interactions (CYP3A4 inducers). A consumer drug reference gives a moderate interaction rating with drugs that speed up the CYP3A4 liver enzyme, such as carbamaze… |
| Borage | Medicine interactions. Memorial Sloan Kettering advises against borage oil with liver-toxic medicines such as anabolic steroids and ketoconazole, and ca… |
| Boswellia | Bleeding risk with blood thinners. Boswellia extracts can inhibit platelet clumping and may raise bleeding risk with anticoagulant or antiplatelet drugs such as war… |
| Boswellia | Drug-transporter effects. In laboratory studies boswellic acids affect drug transporters such as P-glycoprotein and OATP1B3. Whether this matters in people… |
| Bugleweed | Interference with thyroid medicines. Consumer reference sources say bugleweed (and lemon balm) may interfere with thyroid hormone medicines such as levothyroxine, and… |
| Bupleurum | Medicine interactions (liver enzymes). Lab tests suggest bupleurum may affect drugs cleared by CYP2C9, and animal studies suggest it may switch on CYP2E1, 2D6 and 3A4. … |
| Butcher's broom | Safety: side effects, interactions and gaps. No side effects had been reported at the time of the EU assessment, and the one trial reported good tolerability with one possibl… |
| Butterbur | Medicine interactions. NCCIH advises talking with a health care provider before use if you take any medicine, because some herbs and medicines interact … |
| California poppy | Possible interaction with sedating medicines. Because the extract seems to act on benzodiazepine receptors in mice, combining it with sedating medicines is a question for a ph… |
| Cat's claw | Possible interactions with medicines. NCCIH notes theoretical reasons to suspect interactions with blood thinners, antiplatelet drugs, blood pressure drugs and other s… |
| Catnip (herb for people) | Safety in pregnancy, children and with medicines not described. The sources we read did not describe safety in pregnancy, breastfeeding, children or with medicines in people. Absence of informa… |
| Catuaba | Possible interaction with antidepressants. A consumer drug reference advises checking with a provider if taking SSRIs, SNRIs or MAOIs; research is incomplete. |
| Chamomile | Interactions with warfarin and liver-processed medicines. Interactions have been reported with warfarin and some medicines processed by the liver; an interaction with sedatives is theoret… |
| Chanca piedra | Medicines and supplements to discuss with a provider. A consumer drug reference lists diuretics and magnesium or potassium supplements for discussion with a provider and says interact… |
| Chaparral (creosote bush) | Medicine interactions and people at higher risk. Memorial Sloan Kettering describes no specific drug interactions. The National Academies monograph advises most concern for peopl… |
| Chasteberry | Hormone medicines and contraceptives. Laboratory studies suggest chasteberry may reduce the effect of birth control pills and other hormone medicines. The clinical mea… |
| Chasteberry | Antipsychotic and Parkinson's disease medicines. Laboratory studies suggest it may change how antipsychotic and Parkinson's disease medicines work. The clinical meaning is not kn… |
| Chia | Blood pressure and blood sugar medicines. MSK says chia may add to the effect of blood pressure medicines and may lower blood sugar so could interact with diabetes treatme… |
| Chinese asparagus root (tian men dong) | Possible interaction with medicines (liver enzymes). In animal studies the herb switched on the liver enzymes CYP2E1 and CYP1A2, which clear many medicines. Memorial Sloan Kettering … |
| Chirata | Possible low blood sugar with diabetes medicines. Because extracts lowered glucose in animals, a drop in blood sugar with diabetes medicines is a theoretical concern. No confirmed… |
| Chlorella | Warfarin and vitamin K. LactMed says chlorella's high vitamin K content may decrease warfarin effectiveness. |
| Chuanxiong | Possible bleeding and warfarin interaction. In rats, chuanxiong given with warfarin raised warfarin levels by roughly two thirds to nearly three quarters. No human study was… |
| Cinchona bark | Medicine interaction with antacids. MedlinePlus says magnesium or aluminium antacids should not be taken at the same time as quinine. |
| Cinnamon | Possible medicine interactions. NCCIH says, for theoretical reasons, some cinnamon components may interact with an anticancer medicine or nicotine. Anyone on med… |
| Cinnamon twig (gui zhi) | Cinnamon with statins and liver-enzyme medicines. MSK reports hepatitis when cinnamon was taken with statins, and lab findings that cinnamon may raise side effects of some medicin… |
| Cissus quadrangularis | Low blood sugar with diabetes medicines. A consumer reference says Cissus may lower blood sugar, so combining it with diabetes medicines could cause blood sugar to fall t… |
| Coleus forskohlii (forskolin) | Blood pressure medicines (documented caution). Forskolin may add to the effect of blood pressure medicines; low blood pressure and fast heart rate are listed adverse reactions. |
| Coleus forskohlii (forskolin) | Platelets and blood thinners (documented caution). Forskolin may inhibit platelet aggregation, which could raise bleeding or bruising risk with anticoagulants or antiplatelet medic… |
| Coleus forskohlii (forskolin) | Drug-metabolising enzymes (documented caution). Forskolin may induce CYP3A enzymes, which could change how the body handles some medicines. |
| Coptis (goldthread) | Interactions with other medicines. Berberine raised cyclosporine blood levels in kidney-transplant recipients, and may affect tacrolimus, sulfonylurea diabetes medi… |
| Corn silk | Interaction with diuretics, heart and diabetes medicines (theoretical). No human interaction study was found; the diuretic, potassium and blood sugar findings are a reason to ask a pharmacist. |
| Corydalis | Medicine interactions (dopamine medicines, others). WebMD says corydalis may reduce the effect of dopamine-type medicines for Parkinson's disease or restless legs and may slow the l… |
| Cranberry | Possible interaction with warfarin. Evidence is conflicting on whether cranberry affects warfarin. Anyone on warfarin should ask the prescriber or pharmacist first. |
| Cranesbill (wild geranium) | Unknown safety and drug interactions. Reliable safety information for swallowing or skin use is lacking, and drug interactions are unknown. Unknown does not mean safe. |
| Curculigo (kali musli) | Pregnancy, breastfeeding, children, medicines and surgery. No human safety or interaction data were found in the sources read, so use in these situations is unstudied. |
| Cuscuta seed (tu si zi) | Hormone medicine interaction (possible). The review says seed flavonoids might influence androgen, estrogen and progesterone receptors, possibly affecting contraceptives … |
| Cuscuta seed (tu si zi) | Immune-suppressing and liver-enzyme-processed medicines (possible). The review says a seed compound (kaempferol) may counteract immunosuppressants and that flavonoids may alter cytochrome P450 or c… |
| Damiana | Possible medicine interactions (liver enzymes). A damiana leaf extract strongly blocked the liver enzymes CYP3A4 and CYP1A2 in laboratory tests, which hints at possible medicine… |
| Damiana | Blood sugar and diabetes medicines. Because animal studies suggest damiana may lower blood sugar, MSK notes its effects could matter for people on diabetes medicines… |
| Dandelion | Medicine interactions not studied. The EU monograph lists no interactions, but that means none were reported, not that none exist. Dandelion is promoted as a diuret… |
| Danshen (red sage root) | Bleeding risk with warfarin. Case reports describe dangerous over-thinning of the blood and bleeding in people on long-term warfarin who also took danshen, an… |
| Danshen (red sage root) | Bleeding with oral anticoagulants (hospital database). In 525 patients prescribed danshen with oral anticoagulants, 146 had bleeding; risk of any bleeding was about four times higher i… |
| Danshen (red sage root) | Aspirin and clopidogrel interactions. A small trial in 14 healthy volunteers found a danshen-kudzu product changed how aspirin and warfarin were handled. A review repo… |
| Devil's claw | Possible interaction with warfarin. A 2000 pharmacy review listed devil's claw among products with reports of possible interaction with warfarin. |
| Dhataki (fire-flame bush) | No human safety data (pregnancy, medicines, long-term use). No human safety study, pregnancy data or herb-medicine interaction study was found in the sources read. Animal safety numbers exi… |
| Dong quai | Raises bleeding risk with blood thinners (warfarin). A case report described a woman stable on warfarin whose clotting time (PT/INR) more than doubled after 4 weeks of dong quai. The… |
| Dong quai | Changes how some medicines are processed. Long use may speed up a liver enzyme (CYP3A4) and could lower levels of some medicines; two case reports found it increased cloza… |
| Dragon's blood (sangre de grado) | Dacomitinib interaction. Memorial Sloan Kettering advises against taking crofelemer with dacomitinib because animal studies suggest it may worsen that dru… |
| Dragon's blood (sangre de grado) | Side effects and liver enzyme changes seen with the drug. In three placebo-controlled trials (696 people), reactions included respiratory infections, cough, gas, nausea, raised bilirubin … |
| Echinacea | Possible interaction with medicines. NCCIH says evidence is conflicting for interaction with some drugs processed by the liver, with theoretical concern for immunosup… |
| Elderberry | Use with medicines. NCCIH advises anyone taking medicine to talk with their health care provider before using elderberry, because some herbs and medi… |
| Eleuthero | Digoxin: raised levels and false lab readings. A case report found raised digoxin levels, and the herb may cause falsely high digoxin test results. The EMA report questions tha… |
| Eleuthero | Bleeding reports with antidepressants. A review of adverse-event reports listed eleuthero with bleeding events in people also taking some antidepressants. These are rep… |
| Eucalyptus | Effects on drug-processing liver enzymes. Lab and animal studies, and a small 1970 human study of 5 volunteers, suggest cineole can speed up liver enzymes that break down … |
| Evodia (wu zhu yu) | Medicine interactions (CYP enzymes). Laboratory studies say rutaecarpine and evodiamine affect liver enzymes including CYP1A2, 2C9, 2C19, 2E1 and 3A4; in mice rutaeca… |
| False unicorn root | Possible effect on drug-processing liver enzymes (laboratory). In a 2011 test-tube study, four commercial women's herbal products including false unicorn each slowed some drug-processing enzym… |
| Fennel | Duration of use and medicine interactions. The EU says adults should not use fennel tea for more than 2 weeks and should see a doctor if symptoms persist. The monograph rep… |
| Fenugreek | Low blood sugar with diabetes medicines. Large amounts may cause a harmful drop in blood sugar (NCCIH). EMA says blood glucose should be monitored closely in people with … |
| Feverfew | Possible medicine interactions. NCCIH says feverfew may interact with some medicines, including some migraine drugs. Ask a pharmacist or prescriber before combin… |
| Flaxseed | Slower absorption of other medicines; blood thinners. The EMA says fiber such as linseed can delay absorption of other medicines and should be used under medical supervision with medi… |
| Forsythia | Possible bleeding risk and blood-thinner interaction. A clinical monograph says forsythia might slow blood clotting, lists a moderate interaction with anticoagulant and antiplatelet m… |
| Foxglove | Link to the heart medicine digoxin. Foxglove contains digitalis, the same family of compounds as the prescription medicine digoxin. Digoxin itself is a purified drug… |
| Garcinia cambogia | Possible medicine interactions. NCCIH says Garcinia may interact with medicines that affect the liver or serotonin. In the lab it blocked the enzyme CYP2B6, whic… |
| Garcinia cambogia | Serotonin-related problems and mania (case reports). A 2021 review describes reports of serotonin toxicity and mania with Garcinia products. The Australian and WHO adverse-event data… |
| Gardenia fruit (zhi zi) | Bowel vein changes after long-term patent medicines (single case). One case report: an older woman who took Chinese patent medicines containing gardenia fruit for over 15 years developed mesenteri… |
| Gardenia fruit (zhi zi) | Possible effect on liver enzymes (CYP450). A review proposes that genipin, formed from geniposide, can bind proteins and inactivate liver CYP450 enzymes in animals, which c… |
| Gentian | Medicine interactions: none reported. The EU monograph states no interactions have been reported. That is an absence of reports, not proof of safety, so ask a pharmaci… |
| Ginger | Bleeding risk with blood thinners and NSAIDs. Memorial Sloan Kettering advises against ginger supplements with warfarin, other blood thinners, NSAIDs, or bleeding disorders, c… |
| Ginger | Other medicine interactions (diabetes drugs, tacrolimus, cyclosporine). Memorial Sloan Kettering notes ginger may deepen the glucose drop from diabetes medicines, may raise tacrolimus levels, and may l… |
| Goat's rue | Low blood sugar with diabetes medicines. LactMed says the leaves contain guanidine compounds such as galegine that may cause low blood sugar, and advises caution with ant… |
| Goldenseal | Possible effect on medicines (metformin and others). Goldenseal changed how the body handled some medicines in studies. Metformin levels fell by about a quarter in healthy adults, an… |
| Goldenseal | Metformin interaction in type 2 diabetes. In adults with type 2 diabetes, overall metformin exposure did not change in a clinically meaningful way, but it dropped about 20… |
| Grape seed extract | Bleeding risk with blood thinners. In lab tests the extract showed antiplatelet activity. MSK advises people on warfarin and similar drugs to talk with their provid… |
| Grape seed extract | Changes in how some medicines are processed. In lab tests the extract inhibited the CYP3A4 enzyme and affected UGT enzymes, which could change levels or side effects of medic… |
| Gravel root (Joe-Pye weed) | Interaction with lithium. RxList rates a moderate interaction: gravel root may act as a diuretic and slow lithium clearance, which could raise lithium leve… |
| Gravel root (Joe-Pye weed) | Interaction with liver-enzyme inducing medicines. RxList rates a moderate interaction with carbamazepine, phenobarbital, phenytoin, rifampin and rifabutin, which may speed breakdo… |
| Graviola (soursop) | Blood sugar lowering (animals) and diabetes-medicine interaction. In animals graviola lowered blood sugar. MSK says it may add to the effect of diabetes medicines; clinical relevance is unknown. |
| Graviola (soursop) | Blood pressure lowering (animals) and blood-pressure-medicine interaction. In animals graviola lowered blood pressure. MSK says it may add to the effect of blood-pressure medicines; clinical relevance has… |
| Great burnet (di yu) | Possible herb-drug interactions (unstudied). No interaction study was found. Because the root is used for bleeding and blood sugar, ask a pharmacist if you take blood thinner… |
| Greater celandine | Medicines that can harm the liver. German rules, described by EMA, say products containing greater celandine are contraindicated with other liver-damaging medicines… |
| Green coffee bean | Medicine interactions. A consumer drug reference lists 27 interactions, mostly caffeine-related, including blood thinners, stimulants, theophylline, lit… |
| Griffonia (5-HTP source) | Serotonin syndrome with antidepressants and other serotonin medicines. MedlinePlus rates 5-HTP with antidepressants (SSRIs, tricyclics, MAO inhibitors) as a major interaction; it also lists cautions w… |
| Guarana | Interactions with stimulants, blood thinners and amiodarone. Combining with other stimulants may not be safe. Lab studies show antiplatelet activity, so bleeding risk with warfarin is possib… |
| Guava leaf | Blood-sugar medicines and low blood sugar. Trials reported no low blood sugar in people taking diabetes medicines, but the authors say interactions with common medicines ar… |
| Guayusa | Stimulant interaction (ephedrine). A consumer drug reference lists a major interaction with ephedrine and other stimulants, raising the risk of serious heart and bl… |
| Gymnema | Interaction with diabetes medicines (low blood sugar). In studies of people already taking diabetes drugs, low blood sugar episodes occurred and doses had to be adjusted. EFSA warned t… |
| Gymnema | Possible effect on medicine-processing enzymes. A rat study of an ethanol extract suggested possible interactions with the CYP2C9, CYP3A4 and CYP1A2 enzymes that process many dr… |
| Haritaki | Possible effects on liver enzymes and medicine levels. In rats a fruit compound switched on several liver enzymes that break down medicines; MSK advises against triphala with medicines… |
| Hawthorn | Possible interaction with digoxin and heart or blood-pressure medicines. Ask a pharmacist or prescriber before combining hawthorn with digoxin or other heart medicines. A small trial in 8 healthy people… |
| Heather (ling) | Medicine interactions unknown. It is not known whether heather interacts with medicines; ask a pharmacist, especially with diuretic or kidney-affecting medicine… |
| Hibiscus | Risk: may lower simvastatin levels. In six healthy volunteers, a hibiscus drink lowered the body's exposure to a single dose of simvastatin. The authors advised caut… |
| Hibiscus | Risk: additive blood-pressure lowering with blood pressure medicines (reasoned caution). Because hibiscus can lower blood pressure, taking it with blood pressure medicines could lower pressure further. This combination… |
| Honeysuckle (Lonicera) | Medicine and surgery interactions not established. We did not read a reliable source describing honeysuckle interactions with named medicines or bleeding risk. Some websites mentio… |
| Hoodia | Possible medicine interactions (CYP3A4). MSK says people taking medicines that are substrates of the enzyme CYP3A4 should not take hoodia; clinical relevance is not yet d… |
| Horehound | Possible effects on blood sugar and blood pressure (medicine interactions). RxList, a consumer reference, says horehound may lower blood sugar and blood pressure and so may add to diabetes and blood-pressu… |
| Horny goat weed | Medicine interactions (CYP3A4 drugs, aromatase inhibitors). Prolonged use may induce the CYP3A4 enzyme, and icariin may raise aromatase, which could weaken aromatase inhibitor breast cancer… |
| Hydrangea root | Lithium interaction. A consumer drug reference rates a moderate interaction: a diuretic-like effect might reduce lithium clearance and raise its level. |
| Hyssop | Pregnancy, children, liver, kidney, medicines and surgery. The sources read give no information on these; the 1999 report included a child who had seizures after essential oils and recover… |
| Iceland moss | Possible delay in absorption of other medicines. The EU advises taking it at least half an hour to an hour away from other medicines as a precaution because the gel-like fibre mi… |
| Imperata (bai mao gen) | Potassium content and kidney or medicine caution. The review says high potassium content may contribute to the diuretic effect but gives no values. No source we read describes pot… |
| Irvingia (African mango seed) | Added blood-sugar lowering with diabetes medicines. MSK advises against use with diabetes medicines; a consumer drug reference rates the interaction as moderate and advises close bl… |
| Irvingia (African mango seed) | Possible testosterone-raising effect and testosterone interaction (consumer reference only). A consumer drug reference says Irvingia might raise testosterone and rates a testosterone interaction as moderate. |
| Isatis (ban lan gen) | Interaction with CYP3A4 medicines. Indirubin activates CYP3A4 gene transcription through the pregnane X receptor and may change levels of medicines the enzyme handl… |
| Jamun (Java plum seed) | Possible extra blood-sugar lowering with diabetes medicines. Because jamun may lower glucose, it could add to the effect of insulin or diabetes tablets. |
| Japanese knotweed (hu zhang) | Risk: changes how medicines are processed. Resveratrol (1 g a day for 4 weeks) slowed CYP3A4, CYP2D6 and CYP2C9 and sped CYP1A2 in healthy volunteers, so some medicine leve… |
| Japanese knotweed (hu zhang) | Risk: bleeding with blood thinners. Resveratrol inhibits platelet clumping in lab tests, so it may add to bleeding risk with blood thinners such as warfarin. |
| Jiaogulan | Possible interaction with antidepressants. A review of adverse-event reports listed one report of back pain when Gynostemma was combined with duloxetine, and advises monito… |
| Job's tears (coix seed) | May lower blood sugar; diabetes medicines and surgery. A consumer reference lists a moderate interaction with diabetes medicines through possible blood sugar lowering and suggests stop… |
| Jujube | Added drowsiness and medicine interactions (seed). MSK says the seed formula may increase drowsiness from some prescription medicines and names possible interactions with SRIs and … |
| Juniper Berry | Medicine interactions and side effects. The monograph reports no known interactions and no known side effects, and no overdose cases have been reported. |
| Kanna | Serotonin and medicine interaction (psychoactive). Kanna extract blocks the serotonin transporter in lab tests, like SSRI antidepressants. A medicine-information page lists SSRIs, … |
| Kava | Medicine interactions. MSK lists benzodiazepines and other sedatives, acetaminophen (more liver toxicity in lab studies) and medicines handled by CYP1A2… |
| Kokum | Pregnancy, breastfeeding and medicine interactions unknown. NCCIH says little is known about Garcinia cambogia products in pregnancy and breastfeeding and mentions possible interactions wit… |
| Kola nut | Interactions with medicines. The EMA report notes caffeine interactions with MAO-inhibitor drugs and says kola was noted to interact potentially with several … |
| Kratom | Overdose and deaths (mostly with other drugs). Fatal overdose from kratom alone appears extremely rare, but US poison-center data record hundreds of kratom-associated deaths, m… |
| Kratom | Interactions with medicines and other substances. NCCIH links combining kratom with other drugs to deaths and severe effects. Poison-center reports with several substances had mor… |
| Kudzu | Interaction with tamoxifen and methotrexate. MSK lists tamoxifen (kudzu may counteract it) and methotrexate (higher drug levels in an animal study) as medicines not to combin… |
| Kudzu | Interaction with diabetes medicines and liver enzymes. MSK says animal data suggest kudzu may increase the effect of antidiabetic drugs and lab data show puerarin affects CYP2D6 and CY… |
| Kutki | Limited safety data and unknown interactions. Long-term and high-dose safety is under-studied, and the review lists no specific drug interactions. A pharmacist should be told … |
| Lady's mantle | Unknown pregnancy, breastfeeding and medicine-interaction safety. We found no statement on pregnancy, breastfeeding or medicine interactions in the sources we read, so safety there is not establi… |
| Lavender | Possible added sedation with sedative medicines. Lavender might add to the effect of sedative drugs or herbs, which matters before surgery. |
| Lemon balm | Limits of safety data: age, pregnancy, interactions. The EU conclusions cover adults and children over 12 only. The sources read say nothing about pregnancy, breastfeeding or medicin… |
| Lemon verbena | Possible additive effect with blood pressure medicines. Because pooled trials found lower blood pressure on average, anyone taking blood pressure (or diabetes) medicines should ask a ph… |
| Lemongrass | Medicine interactions (research gap). The scoping review called for more research on interactions with medicines. No specific interactions are described in the sources… |
| Licorice root | Medicine interactions. Licorice may work against blood pressure medicines. The EU monograph advises against using it with water pills, heart glycosides,… |
| Ligustrum (glossy privet) | Poisonous garden plant (not the medicine). Distinguishes the raw plant from the prepared dried fruit. |
| Long pepper | Possible change in how medicines are absorbed. Piperine, the main pungent compound of long pepper and black pepper, blocks a medicine transporter (P-glycoprotein) and a liver e… |
| Lotus seed (lian zi) | Missing safety data (pregnancy, children, interactions, toxicology). The sources read give no pregnancy, breastfeeding, children or herb-drug interaction data for lotus seed, and the plumule review … |
| Lycium root bark (di gu pi) | Possible added effect with diabetes and blood pressure medicines. Because animal studies point to lower blood sugar and pressure, ask a prescriber or pharmacist before combining the bark with suc… |
| Lycium root bark (di gu pi) | Goji fruit warfarin and allergy reports (fruit, not bark). The MSK page on goji fruit describes raised INR with warfarin and allergy in people with lipid transfer protein allergy. It does … |
| Maca | Possible interaction with antidepressants. A review of adverse-event reports listed one report of restless legs syndrome with maca and the antidepressant mianserin. These a… |
| Magnolia bark | Sedative and medicine interactions. A consumer drug reference warns magnolia may add to drowsiness from sedatives, sleep medicines and barbiturates. The lab authors … |
| Magnolia bark | Bleeding with blood thinners. WebMD does not recommend combining magnolia with blood thinners including aspirin because of bleeding risk. |
| Mangosteen | Possible interaction with medicines processed by P450 enzymes. MSK says lab work shows mangosteen compounds inhibit several P450 enzymes, which may raise side-effect risk of drugs processed th… |
| Meadowsweet | Use with salicylates, NSAIDs or blood thinners. The EU monograph says use with salicylates or other NSAIDs is not recommended without medical advice. EU reviewers judged interac… |
| Milk Thistle | Medicine interactions. NIH advises talking to a health professional before using any herb with medicines. The page we read lists no specific milk thistl… |
| Morinda root (ba ji tian) | Blood sugar and diabetes medicines. A consumer drug reference warns the root may raise or lower blood sugar and change how diabetes medicines work. |
| Moringa | Medicine interactions (CYP3A4, sitagliptin, diabetes medicines). Memorial Sloan Kettering reports lab data that moringa may inhibit CYP3A4 and raised rifampin levels, and an animal study in whic… |
| Motherwort | Interactions and side effects not well described. No side effects had been reported when the committee assessed it, and the public summary does not address drug interactions. That… |
| Mucuna pruriens (velvet bean) | Interaction with levodopa and other Parkinson's medicines. Mucuna is a dopamine-raising drug source; interactions with other Parkinson's medicines are described as poorly studied, and self… |
| Mucuna pruriens (velvet bean) | MAO-inhibitor and other medicine cautions (inferred from levodopa). Levodopa medicine information tells patients to report MAO-inhibitor use, iron products and all other medicines. The same caution… |
| Mulberry leaf | Low blood sugar when combined with diabetes medicines. Taking mulberry leaf with diabetes medicines may push blood sugar too low. |
| Mullein | Side effects and interactions: none reported, not proven absent. No side effects or interactions were reported at the time of the EU assessment. Long-term safety is not described. |
| Myrrh | Warfarin interaction. MSK advises against taking myrrh with warfarin, citing a case report in which warfarin's effect appeared weaker. |
| Nasturtium (garden) | Pregnancy, breastfeeding, children and medicines. The sources we read do not describe pregnancy, breastfeeding, children or medicine interactions for nasturtium. Trials enrolled a… |
| Neem | Possible medicine interactions (liver enzymes). In laboratory work, a neem extract inhibited the liver enzymes CYP3A4/5, CYP2C8 and CYP2C9. MSK says the clinical relevance is un… |
| Noni | Possible medicine interactions. Noni may be unsafe with medicines that raise potassium, lower blood pressure or harm the liver. Case reports describe weaker effe… |
| Notopterygium (qiang huo) | Possible interaction with medicines cleared by CYP2D6. In a test-tube study with human enzymes, notopterol irreversibly blocked CYP2D6, an enzyme that clears many medicines, and the au… |
| Nut grass (mustaka, xiang fu) | Extract plus piperine; interactions not studied. The 2025 trial gave the extract with piperine. Medicine interactions were not studied in the sources we read. |
| Oat straw (milky oats) | Medicine interactions and safety in pregnancy. No interaction or pregnancy statement was found in the sources we read. EMA says its monograph holds precautions, which we could … |
| Olive leaf | Possible added effect with blood pressure or diabetes medicines. Because trials show blood pressure and blood sugar effects, a prescriber should know about olive leaf use. No specific interactio… |
| Ophiopogon (mai dong) | Possible interaction with chemotherapy is untested. A computer-based study suggested a Shengmai formula might enhance chemotherapy effect; it is a hypothesis only, not tested in peo… |
| Oregano | Interaction with vitamin K blood thinners. A case report describes a 77-year-old woman on acenocoumarol whose INR reached 6.42 after about a week of daily oregano tea (some… |
| Oregon grape | Possible effect on how medicines are absorbed. In cell experiments, root extracts changed a drug transporter (P-glycoprotein) that moves medicines such as cyclosporine and digo… |
| Panax notoginseng | Possible interaction with warfarin. In rats, giving notoginseng saponins with warfarin raised clotting-time measures (PT and INR) compared with warfarin alone and sl… |
| Panax notoginseng | Added antiplatelet effect with clopidogrel. A review reports that notoginseng increased antiplatelet activity compared with clopidogrel alone. A separate review of trials fo… |
| Panax notoginseng | Effects on drug-handling enzymes and transporters. A review of herb-medicine interactions found notoginseng and its compounds alter how the body handles other drugs, mainly through… |
| Papaya leaf | Possible medicine interactions (lab and animal data). Lab and animal studies suggest effects with metformin and glimepiride (stronger blood-sugar lowering), digoxin (less absorption),… |
| Passionflower | Surgery and anesthesia interaction. Passionflower might interact with some anesthesia drugs and slow the nervous system too much. NIH advises avoiding it before surg… |
| Pau d'arco | Bleeding risk with blood thinners. Lapachol is thought to block vitamin K-related enzymes in a way similar to warfarin, so pau d'arco may add to the effect of antic… |
| Pennyroyal | Medicine interactions. MSK describes a case of acute liver failure possibly caused by an interaction with pennyroyal tea, notes CYP2E1 is the main enzym… |
| Peony (white peony root) | Medicine interactions (limited data). EMA found no specific interaction data for the root. A peony extract delayed phenytoin absorption in rats but did not change valp… |
| Peppermint | Capsule coating and acid-reducing medicines (documented interaction). Acid-reducing medicines (H2 blockers, proton pump inhibitors) may make enteric coatings dissolve too early, and capsules should b… |
| Periwinkle | Possible added effect with blood thinners. Memorial Sloan Kettering lists possible additive effects with anticoagulant and antiplatelet medicines and a higher bleeding risk. |
| Periwinkle | Possible added effect with blood pressure medicines. The same reference says vinpocetine may increase the blood-pressure-lowering effect of medicines for high blood pressure, and low… |
| Periwinkle | Possible effect on how other medicines are handled. In laboratory studies vinpocetine strongly inhibited P-glycoprotein, a protein that moves drugs around the body; MSK says the cli… |
| Phellodendron | Medicine interactions (transplant drugs, liver enzymes, diabetes drugs). For berberine, Memorial Sloan Kettering reports raised cyclosporine levels in kidney-transplant adults, a tacrolimus case in a ch… |
| Pinellia (ban xia) | Possible interactions (aconite, cancer drugs). A search summary says the Chinese Pharmacopoeia forbids combining ban xia with processed aconite (disputed). One laboratory study… |
| Platycodon (balloon flower) | Safety with chemotherapy and other medicines is not established. The 2023 review reports no adverse interactions but describes combinations with cancer drugs only in cells and animals and does n… |
| Pleurisy root | Digoxin and other heart medicines. A consumer drug reference lists digoxin as a major interaction and advises against the combination. PeaceHealth lists beta-blocke… |
| Polygonatum (huang jing, Solomon's seal) | Interaction and pregnancy data gaps. No human herb-drug interaction study, pregnancy or breastfeeding safety data, or children's data were found in the sources read. … |
| Prickly ash (northern) | Minor interactions with acid-reducing medicines. The consumer drug reference lists minor interactions with antacids, H2 blockers and proton pump inhibitors because more stomach a… |
| Prickly pear (nopal) | Low blood sugar with diabetes medicines. A consumer drug reference reports case reports of low blood sugar when prickly pear is combined with diabetes drugs; another list… |
| Psyllium | Risk: slows absorption of other medicines. The EU monograph says absorption of minerals, vitamin B12, heart glycosides, coumarin blood thinners, carbamazepine and lithium m… |
| Psyllium | Risk: diabetes and thyroid medicines may need adjusting. The EU monograph says people with diabetes should use psyllium under medical supervision, and thyroid hormone doses may need adju… |
| Pygeum | Drug interactions and long-term safety. The EU monograph and assessment report report no known drug interactions, but this is an absence of reports, not proof of safety.… |
| Qin jiao (large-leaf gentian) | Possible interactions with medicines. A 2025 review warns of possible interactions with medicines handled by the liver and with blood-sugar control, without naming spe… |
| Rasna | No human safety data for interactions, pregnancy or children. The sources we read give no interaction, pregnancy, breastfeeding, child, liver or kidney safety data for Rasna. |
| Red clover | Possible bleeding with blood thinners. May add to the effect of anticoagulant and antiplatelet drugs. The evidence is preclinical studies and case reports; clinical rel… |
| Red clover | Effects on drug-clearing liver enzymes and methotrexate. Preclinical studies suggest inhibition of several CYP450 enzymes (clinical relevance not determined). One case report links use w… |
| Rehmannia | Possible medicine interactions (unproven). One herbal database says rehmannia may interact with immunosuppressants, diuretics and corticosteroids but gives no mechanism or … |
| Rhodiola | Interaction with antidepressants. A case report described a fast, irregular heartbeat in a woman who took rhodiola with an antidepressant for three days. Lab work … |
| Rhodiola | Interaction with other medicines. NCCIH reports interactions with losartan. MSK lists possible effects on drugs cleared by CYP2C9 (warfarin, phenytoin), CYP3A4 and… |
| Rhubarb root | Risk: interactions with medicines. MSK lists digoxin (potassium loss), CYP450 medicines, melatonin, cyclosporine and methotrexate; the clinical importance of the la… |
| Rooibos | Lower tacrolimus levels (transplant drug interaction). MSK describes a patient who drank over 2 liters daily after a bone marrow transplant and had reduced tacrolimus levels with graft… |
| Safflower | Bleeding risk and blood thinners. A consumer drug reference lists blood thinners and antiplatelet drugs as medicines to check with safflower flower. A 2025 review … |
| Saffron | Bleeding risk with blood thinners. A case report described acute bleeding in a man taking rivaroxaban with a saffron supplement. Lab tests suggested saffron affecte… |
| Sage | Long-term use, children and interactions. NCCIH says sage may be unsafe at high doses or for long periods; amounts above food levels were used safely for up to 8 weeks in … |
| Salacia | Low blood sugar with diabetes medicines. A consumer drug reference rates the combination with diabetes drugs, including insulin, as a moderate interaction because blood s… |
| Sariva (Indian sarsaparilla) | No human safety or interaction data. We found no human trial, case report, interaction study or regulator statement. Pregnancy, breastfeeding, children and medicine u… |
| Sarpagandha (Indian snakeroot) | Interactions with heart, Parkinson and mood medicines. The label advises caution with digoxin or quinidine, avoiding levodopa and MAO inhibitors, and notes added sedation with alcohol … |
| Sarsaparilla | Interactions with digoxin and lithium. Sarsaparilla might raise absorption of digoxin and, through a water-pill-like effect, might raise lithium levels. RxList rates bo… |
| Sassafras | Safrole as a drug-precursor chemical. Safrole is a US DEA List I chemical, and NTP notes it has been used in illicit production of MDMA (ecstasy). |
| Saw palmetto | Medicine interactions. Possible increased side effects with NSAIDs. In the lab it inhibits liver enzymes (CYP3A4, 2D6, 2C9, UGT) that clear some medicin… |
| Schisandra | Medicine interactions via liver enzymes and P-glycoprotein. Lab and animal studies suggest schisandra can affect medicines broken down by CYP1A2, CYP3A4 or CYP3A5 and may raise side effects… |
| Scotch broom | MAOI antidepressant interaction (tyramine). The reference lists a major interaction with MAOI antidepressants because it says the plant contains tyramine, which can lead to … |
| Scotch broom | Other medicine interactions (haloperidol, quinidine, lithium). The reference lists major interactions with haloperidol and quinidine (slower breakdown of the plant's compounds) and a moderate … |
| Self-heal | Limited safety data and medicine interactions. Toxicity and side effects are little studied and interactions with medicines are not well characterized. |
| Senna | Medicine interactions. The NHS says senna may not mix well with some heart medicines, water tablets (diuretics), steroids and products containing liquor… |
| Shepherd's purse | Unconfirmed medicine and thyroid warnings. A consumer health article warns about blood thinners, sedatives and thyroid problems, but says human safety studies are lacking. … |
| Silverweed | Possible delayed absorption of other medicines (from related tormentil). For tormentil, the HMPC says absorption of other medicines may be delayed and advises taking it an hour or more apart. Not tested… |
| St. John's wort | Interactions with many medicines. It can weaken or change many medicines, including some antidepressants, birth control pills, cyclosporine, anti-seizure drugs, he… |
| St. John's wort | Serotonin-related side effects with antidepressants. Taken with certain antidepressants or other drugs that affect serotonin, it may increase serotonin-related side effects, which ca… |
| Stinging nettle | Possible interaction with blood sugar medicines. A case report describes low blood sugar in a 78-year-old man taking a nettle-containing BPH remedy; the product was a mixture, so… |
| Stinging nettle | Possible interaction with diuretics, blood pressure medicines and liver-processed drugs. Based on animal studies, nettle may add to diuretics and blood pressure medicines and may inhibit CYP450 enzymes. Clinical releva… |
| Stone root | Possible interactions with blood thinners, blood pressure medicines and diuretics. Hobbs says it may interact with anticoagulants and blood pressure medicines; Healthline raises dehydration and interactions from … |
| Suma (Brazilian ginseng) | Medicine interactions not studied. Little is known about how suma interacts with medicines; no interaction study was found. |
| Sutherlandia (cancer bush) | Interaction with HIV (antiretroviral) medicines. In a small study of 12 healthy men, sutherlandia lowered the amount of the HIV medicine atazanavir reaching the blood. Lab tests … |
| Sutherlandia (cancer bush) | Possible interaction with tuberculosis-prevention medicine. Two people taking isoniazid with sutherlandia in a 24-week trial developed tuberculosis. The authors called for further study of … |
| Sutherlandia (cancer bush) | Effects on medicine-processing enzymes and transporters. Lab tests showed sutherlandia extracts can inhibit the CYP3A4 enzyme and P-glycoprotein transporter. Whether this matters in peop… |
| Sweet clover (melilot) | Blood thinners (acenocoumarol, warfarin-type medicines). A case report links a cream with melilot and Ruscus extract to a rise in INR in a woman taking acenocoumarol. Spoiled sweet clove… |
| Sweet woodruff | Possible bleeding and blood-thinner interaction. A consumer drug reference says woodruff may slow clotting and rates its interaction with anticoagulant and antiplatelet drugs as … |
| Tagara (Indian valerian) | Added drowsiness with alcohol and sedative medicines (extrapolated from common valerian). NIH says common valerian should not be combined with alcohol or sedatives, and Memorial Sloan Kettering lists prolonged effects w… |
| Tangerine peel (chen pi) | Possible grapefruit-type medicine interactions (unresolved). Grapefruit is well documented to change how some medicines are processed. We did not find a source showing the same for tangerine… |
| Tribulus | Interactions with medicines. Possible added effects with diuretics, blood pressure medicines and diabetes medicines; one report of stent thrombosis with clopi… |
| Triphala | Possible interactions with medicines cleared by CYP enzymes. MSK says triphala blocks the liver enzymes CYP3A4 and CYP2D6 and may raise levels of medicines they clear. Monographs for Termina… |
| Triphala | Blood-sugar lowering and diabetes medicines. Reviews and monographs report triphala or Terminalia chebula may lower blood sugar, so combining with diabetes medicines could ca… |
| Turmeric | Bleeding and medicine interactions. Lab, animal and single-case data suggest higher bleeding risk with warfarin and other blood thinners. Turmeric may lessen the eff… |
| Uncaria (gou teng) | Possible extra blood pressure fall with blood pressure medicine. Because blood pressure lowering is seen in animals, an added effect with antihypertensive drugs is a theoretical concern; no huma… |
| Uncaria (gou teng) | Possible liver-enzyme drug interactions. A 2026 review says gou teng alkaloids may inhibit CYP3A4 and CYP2D6 and activate PXR, which could in theory alter levels of drugs… |
| Usnea (old man's beard lichen) | Blood-thinner and CYP3A4 medicine interactions. Memorial Sloan Kettering notes theoretical additive effects with anticoagulants and animal findings that usnic acid induces CYP3A… |
| Uva Ursi | Medicine interactions: none reported, which is not proof of safety. The monograph says no interactions have been reported. A missing report is different from proof there are none; ask a pharmacist. |
| Vasaka (Malabar nut) | Possible interactions with medicines. A 2026 review covers interactions between asthma medicines and eight herbs, including Adhatoda vasica, through liver enzymes and … |
| Vijaysar (Indian kino) | Low blood sugar with diabetes medicines (precaution). No human study of vijaysar with diabetes drugs was found. An animal study showed the extract plus glibenclamide lowered glucose m… |
| Watercress | Warfarin and vitamin K. Watercress is a strong source of vitamin K (USDA figure quoted on the site food page). The NHS advises people on warfarin to avoi… |
| Watercress | Slower clearance of chlorzoxazone (CYP2E1 medicines). In 10 healthy volunteers, one watercress meal raised chlorzoxazone exposure by about 56% and lengthened its half-life by about 53… |
| Wild cherry bark | Possible slowing of CYP3A4 drug breakdown (documented risk). A consumer drug reference rates a moderate interaction with medicines cleared by the liver enzyme CYP3A4. |
| Wild lettuce | Medicine interactions. A consumer article says wild lettuce may interact with medicines but names none. Combining with sedatives or alcohol is a general… |
| Wild yam | Drug interactions, pregnancy and breastfeeding. MSKCC does not describe drug interactions or pregnancy safety. Absence of information is not proof of safety; ask a pharmacist, e… |
| Willow bark | Risk: aspirin and salicylate allergy. EU regulators list salicylate or NSAID allergy and salicylate-sensitive asthma as reasons not to use willow bark. Case reports de… |
| Willow bark | Risk: bleeding, blood thinners and NSAIDs. Memorial Sloan Kettering says willow bark may add to the bleeding risk of warfarin and other anticoagulants, and the stomach and … |
| Yerba mate | Medicine and condition cautions. The EU monograph says to use caution with MAO-inhibitor drugs, notes that caffeine can weaken sedatives and increase side effects… |
| Yerba santa | Medicine interactions unknown. The consumer drug reference says it is not known whether yerba santa interacts with medicines and suggests talking to a health pr… |
| Yohimbe | Drug interactions. NCCIH says not to use with MAOIs or tricyclic antidepressants. MSK adds possible effects on anxiolytics, blood pressure medicines… |
| Herb | What its guide documents |
|---|---|
| Albizia (mimosa tree bark) | Anaesthesia and surgery. The consumer reference says albizia may add to the effects of anaesthesia; its stop-before-surgery timing appears copied from ano… |
| Amla | Effect on platelets and bleeding time. In a small open-label crossover study of 10 people with type 2 diabetes, amla extract reduced platelet aggregation and lengthened… |
| Arjuna | Possible interactions with heart, blood pressure and blood-thinning medicines. WebMD says arjuna may add to or change the effects of heart, blood pressure, cholesterol, blood-thinning, heart-rhythm and chest-… |
| Arnica | Platelet inhibition and blood-thinner interaction. Arnica inhibited platelet clumping in the laboratory, and MSK warns it may increase the effect of warfarin and other blood thinne… |
| Ashitaba | Bleeding risk, blood thinners and surgery. In rats, high doses lowered platelets and lengthened clotting times (prothrombin and APTT). EFSA did not assess medicine interact… |
| Ashwagandha | Medicine interactions and surgery (documented risk). NCCIH says it might interact with diabetes, blood pressure, immunosuppressant, sedative, anti-seizure and thyroid hormone medicin… |
| Asian ginseng | Blood thinners, clotting and surgery. Ginseng may interfere with blood clotting. Results with warfarin are mixed, and MSK suggests it may raise aspirin levels. MSK adv… |
| Bergamot | Pregnancy, children and surgery cautions. A consumer drug reference advises against bergamot oil on skin in pregnancy and breastfeeding, calls large oral amounts possibly … |
| Bibhitaki | Surgery. Consumer references advise stopping Terminalia about 2 weeks before scheduled surgery because of possible effects on blood sugar … |
| Bladderwrack | Other medicine interactions (blood thinners, blood-pressure drugs, enzyme-handled drugs). The EU lists blood thinners and blood-pressure medicines as possible interactions (other literature considers an effect on vitami… |
| Blessed thistle | Possible interactions (stomach-acid medicines, bleeding). No interactions have been reported. EMA notes in theory it might weaken antacids and acid-reducing medicines, and that a lab plat… |
| Boswellia | Bleeding risk with blood thinners. Boswellia extracts can inhibit platelet clumping and may raise bleeding risk with anticoagulant or antiplatelet drugs such as war… |
| Cat's claw | May slow blood clotting (bleeding risk). NCCIH says cat's claw may slow blood clotting, which might raise bleeding risk during surgery. People having surgery should tell … |
| Chia | Bleeding and clotting. MSK says high amounts of the omega-3 fats in chia could alter bleeding and clotting times. |
| Chitrak (Ceylon leadwort) | Possible bleeding and clotting effects. A plumbagin review says long-term use may cause bleeding by interfering with vitamin K and mentions possible effects on clotting. |
| Chuanxiong | Possible bleeding and warfarin interaction. In rats, chuanxiong given with warfarin raised warfarin levels by roughly two thirds to nearly three quarters. No human study was… |
| Cinchona bark | Blood and bleeding disorders. MedlinePlus warns of severe bleeding and bruising and G-6-PD deficiency. Case reports describe DIC after quinine for cramps and a… |
| Cissus quadrangularis | Surgery. The consumer reference advises stopping at least 2 weeks before scheduled surgery because of blood sugar control effects. |
| Coleus forskohlii (forskolin) | Platelets and blood thinners (documented caution). Forskolin may inhibit platelet aggregation, which could raise bleeding or bruising risk with anticoagulants or antiplatelet medic… |
| Curculigo (kali musli) | Pregnancy, breastfeeding, children, medicines and surgery. No human safety or interaction data were found in the sources read, so use in these situations is unstudied. |
| Damiana | Safety data gaps (pregnancy, children, surgery, liver). The sources read give no information on pregnancy, breastfeeding, children, surgery or liver effects in people. Animal toxicity s… |
| Danshen (red sage root) | Bleeding risk with warfarin. Case reports describe dangerous over-thinning of the blood and bleeding in people on long-term warfarin who also took danshen, an… |
| Danshen (red sage root) | Bleeding with oral anticoagulants (hospital database). In 525 patients prescribed danshen with oral anticoagulants, 146 had bleeding; risk of any bleeding was about four times higher i… |
| Dong quai | Raises bleeding risk with blood thinners (warfarin). A case report described a woman stable on warfarin whose clotting time (PT/INR) more than doubled after 4 weeks of dong quai. The… |
| Eleuthero | Bleeding reports with antidepressants. A review of adverse-event reports listed eleuthero with bleeding events in people also taking some antidepressants. These are rep… |
| Feverfew | May slow blood clotting; stop before surgery. NCCIH says feverfew may slow blood clotting and advises stopping at least 2 weeks before scheduled surgery. |
| Flaxseed | Slower absorption of other medicines; blood thinners. The EMA says fiber such as linseed can delay absorption of other medicines and should be used under medical supervision with medi… |
| Forsythia | Possible bleeding risk and blood-thinner interaction. A clinical monograph says forsythia might slow blood clotting, lists a moderate interaction with anticoagulant and antiplatelet m… |
| Garlic | Bleeding risk and surgery. Garlic supplements may increase the risk of bleeding, so tell your providers, especially before surgery or if you take anticoagul… |
| Ginger | Bleeding risk with blood thinners and NSAIDs. Memorial Sloan Kettering advises against ginger supplements with warfarin, other blood thinners, NSAIDs, or bleeding disorders, c… |
| Ginger | Surgery. Memorial Sloan Kettering advises stopping ginger supplements 2 weeks before surgery because of blood-thinning effects. |
| Grape seed extract | Bleeding risk with blood thinners. In lab tests the extract showed antiplatelet activity. MSK advises people on warfarin and similar drugs to talk with their provid… |
| Griffonia (5-HTP source) | Surgery. MedlinePlus advises stopping 5-HTP at least 2 weeks before surgery because some drugs given during surgery also affect serotonin. |
| Guarana | Interactions with stimulants, blood thinners and amiodarone. Combining with other stimulants may not be safe. Lab studies show antiplatelet activity, so bleeding risk with warfarin is possib… |
| Honeysuckle (Lonicera) | Medicine and surgery interactions not established. We did not read a reliable source describing honeysuckle interactions with named medicines or bleeding risk. Some websites mentio… |
| Horehound | Heart rhythm and surgery cautions. RxList says horehound may cause irregular heartbeat in people with heart problems and advises stopping it at least 2 weeks before… |
| Hyssop | Pregnancy, children, liver, kidney, medicines and surgery. The sources read give no information on these; the 1999 report included a child who had seizures after essential oils and recover… |
| Irvingia (African mango seed) | Pregnancy, breastfeeding and surgery cautions (consumer reference). A consumer drug reference advises avoiding use in pregnancy and breastfeeding for lack of reliable data and stopping 2 weeks befo… |
| Japanese knotweed (hu zhang) | Risk: bleeding with blood thinners. Resveratrol inhibits platelet clumping in lab tests, so it may add to bleeding risk with blood thinners such as warfarin. |
| Job's tears (coix seed) | May lower blood sugar; diabetes medicines and surgery. A consumer reference lists a moderate interaction with diabetes medicines through possible blood sugar lowering and suggests stop… |
| Jujube | Low blood sugar and surgery. A consumer drug reference says jujube may lower blood sugar, advises care with diabetes medicines, and advises stopping at least … |
| Kava | Surgery and anaesthesia. MSK advises stopping kava before surgery because it may interact with anaesthetics and add to sedation. |
| Magnolia bark | Bleeding with blood thinners. WebMD does not recommend combining magnolia with blood thinners including aspirin because of bleeding risk. |
| Meadowsweet | Use with salicylates, NSAIDs or blood thinners. The EU monograph says use with salicylates or other NSAIDs is not recommended without medical advice. EU reviewers judged interac… |
| Morinda root (ba ji tian) | Surgery. A consumer drug reference advises stopping at least 2 weeks before planned surgery because of possible blood-sugar effects. |
| Oregano | Interaction with vitamin K blood thinners. A case report describes a 77-year-old woman on acenocoumarol whose INR reached 6.42 after about a week of daily oregano tea (some… |
| Panax notoginseng | Added antiplatelet effect with clopidogrel. A review reports that notoginseng increased antiplatelet activity compared with clopidogrel alone. A separate review of trials fo… |
| Panax notoginseng | Bleeding disorders and surgery caution. Because the herb is traditionally used to stop bleeding and shows effects on clotting markers, people with bleeding problems or p… |
| Passionflower | Surgery and anesthesia interaction. Passionflower might interact with some anesthesia drugs and slow the nervous system too much. NIH advises avoiding it before surg… |
| Patha (velvetleaf) | Muscle-relaxant and anesthesia caution. Patha alkaloids are isoquinolines; historic curare drug tubocurarine is a surgical muscle relaxant. Sources read do not link path… |
| Pau d'arco | Bleeding risk with blood thinners. Lapachol is thought to block vitamin K-related enzymes in a way similar to warfarin, so pau d'arco may add to the effect of antic… |
| Pau d'arco | High-amount lapachol bleeding and vomiting. PeaceHealth reports that several grams of isolated lapachol a day for several days caused uncontrolled bleeding, nausea and vomit… |
| Periwinkle | Possible added effect with blood thinners. Memorial Sloan Kettering lists possible additive effects with anticoagulant and antiplatelet medicines and a higher bleeding risk. |
| Pueraria mirifica (kwao krua) | Irregular bleeding, menstrual disorders and breast symptoms. Japanese reports describe irregular vaginal bleeding, menstrual disorders, breast swelling and pain and heavy periods with supple… |
| Red clover | Possible bleeding with blood thinners. May add to the effect of anticoagulant and antiplatelet drugs. The evidence is preclinical studies and case reports; clinical rel… |
| Safflower | Bleeding risk and blood thinners. A consumer drug reference lists blood thinners and antiplatelet drugs as medicines to check with safflower flower. A 2025 review … |
| Saffron | Bleeding risk with blood thinners. A case report described acute bleeding in a man taking rivaroxaban with a saffron supplement. Lab tests suggested saffron affecte… |
| Salacia | Surgery. A consumer reference advises stopping salacia at least 2 weeks before planned surgery because it may affect blood sugar control. |
| Sarpagandha (Indian snakeroot) | Surgery and anesthesia. The label advises stopping reserpine one to two weeks before elective surgery because anesthesia can cause unexpectedly low blood… |
| Saw palmetto | Bleeding and surgery risk. Case reports describe extra bleeding, including during surgery and in people on blood thinners such as rivaroxaban. Tell the surg… |
| Schisandra | Pregnancy, breastfeeding and surgery: no safety data found. The sources read give no safety statement for pregnancy, breastfeeding, children or surgery. Animal studies describe effects on u… |
| Sea buckthorn | Safety: possible effect on platelet aggregation and bleeding. A systematic review of herbs tested in healthy people listed sea buckthorn berry among plants that inhibited platelet aggregation… |
| Shepherd's purse | Delay in diagnosing the cause of heavy bleeding. The EU use is only after a doctor has ruled out serious conditions, and symptoms that persist or worsen need medical review. |
| Stone root | Possible interactions with blood thinners, blood pressure medicines and diuretics. Hobbs says it may interact with anticoagulants and blood pressure medicines; Healthline raises dehydration and interactions from … |
| Sweet clover (melilot) | Blood thinners (acenocoumarol, warfarin-type medicines). A case report links a cream with melilot and Ruscus extract to a rise in INR in a woman taking acenocoumarol. Spoiled sweet clove… |
| Sweet clover (melilot) | Spoiled sweet clover and bleeding disease. Moldy sweet clover hay caused fatal bleeding in cattle because molds change coumarin into dicoumarol, which led to the developmen… |
| Sweet woodruff | Possible bleeding and blood-thinner interaction. A consumer drug reference says woodruff may slow clotting and rates its interaction with anticoagulant and antiplatelet drugs as … |
| Sweet woodruff | Surgery. A consumer drug reference advises stopping woodruff at least 2 weeks before planned surgery because of possible effects on clotti… |
| Tagara (Indian valerian) | Stop before surgery (common valerian). Memorial Sloan Kettering advises stopping common valerian at least 1 week before surgery because it may interfere with anaesthesi… |
| Tansy | Liver, kidney and bleeding harm. The thujone monograph lists liver inflammation and intestinal bleeding; the consumer reference adds kidney or liver damage. |
| Triphala | Pregnancy, breastfeeding and surgery cautions. Monographs say safety in pregnancy is unknown or possibly unsafe, advise avoiding it while breastfeeding, and advise stopping at … |
| Turmeric | Bleeding and medicine interactions. Lab, animal and single-case data suggest higher bleeding risk with warfarin and other blood thinners. Turmeric may lessen the eff… |
| Usnea (old man's beard lichen) | Blood-thinner and CYP3A4 medicine interactions. Memorial Sloan Kettering notes theoretical additive effects with anticoagulants and animal findings that usnic acid induces CYP3A… |
| Willow bark | Risk: bleeding, blood thinners and NSAIDs. Memorial Sloan Kettering says willow bark may add to the bleeding risk of warfarin and other anticoagulants, and the stomach and … |
| Herb | What its guide documents |
|---|---|
| Acai | Blood sugar and diabetes medicines. Early research suggests acai may raise or lower fasting blood sugar, so it could interfere with diabetes medicines. |
| American ginseng | Interaction with diabetes medicines. Because blood glucose may fall, people using diabetes medicines should ask a clinician before adding it. |
| Amla | Possible blood-sugar-lowering with diabetes medicines. The trial authors suggested the extract may lower blood sugar. This is a reason to tell your prescriber, not a proven interaction. |
| Asian ginseng | Blood sugar lowering: risk with diabetes medicines. Ginseng may lower blood sugar, so people with diabetes should talk with a provider first. MSK says it may increase low blood suga… |
| Bael | Possible low blood sugar with diabetes medicines (reasoned caution). Because bael is claimed to lower glucose, a diabetes patient should tell the prescriber. No source we read documents an actual in… |
| Bibhitaki | Low blood sugar with diabetes medicines. Bibhitaki might lower blood sugar, so combining it with diabetes medicines or other blood-sugar-lowering herbs could push blood s… |
| Bilberry | Possible blood-sugar lowering with diabetes medicines. Bilberry has been reported to lower blood glucose, so people who take diabetes medicines should ask a pharmacist or doctor first. |
| Bitter leaf | Possible herb-drug interaction with diabetes medicines. In diabetic rats, a leaf extract changed how metformin was absorbed and cleared, and it blocked two liver enzymes in a lab test. … |
| Bitter Melon | Effect on blood sugar medicines. Because bitter melon can lower blood sugar, it may add to diabetes medicines; the sources we read did not describe specific inter… |
| Chia | Blood pressure and blood sugar medicines. MSK says chia may add to the effect of blood pressure medicines and may lower blood sugar so could interact with diabetes treatme… |
| Chirata | Possible low blood sugar with diabetes medicines. Because extracts lowered glucose in animals, a drop in blood sugar with diabetes medicines is a theoretical concern. No confirmed… |
| Cinchona bark | Kidney damage and low blood sugar. MedlinePlus lists kidney damage and low blood sugar as possible effects of quinine. |
| Cissus quadrangularis | Low blood sugar with diabetes medicines. A consumer reference says Cissus may lower blood sugar, so combining it with diabetes medicines could cause blood sugar to fall t… |
| Corn silk | Interaction with diuretics, heart and diabetes medicines (theoretical). No human interaction study was found; the diuretic, potassium and blood sugar findings are a reason to ask a pharmacist. |
| Damiana | Blood sugar and diabetes medicines. Because animal studies suggest damiana may lower blood sugar, MSK notes its effects could matter for people on diabetes medicines… |
| Dandelion | Possible high potassium in kidney failure, diabetes or heart failure. The EU committee says people with kidney failure, diabetes or heart failure should avoid it because of possible high potassium (h… |
| Fenugreek | Low blood sugar with diabetes medicines. Large amounts may cause a harmful drop in blood sugar (NCCIH). EMA says blood glucose should be monitored closely in people with … |
| Ginger | Other medicine interactions (diabetes drugs, tacrolimus, cyclosporine). Memorial Sloan Kettering notes ginger may deepen the glucose drop from diabetes medicines, may raise tacrolimus levels, and may l… |
| Goat's rue | Low blood sugar with diabetes medicines. LactMed says the leaves contain guanidine compounds such as galegine that may cause low blood sugar, and advises caution with ant… |
| Goldenseal | Metformin interaction in type 2 diabetes. In adults with type 2 diabetes, overall metformin exposure did not change in a clinically meaningful way, but it dropped about 20… |
| Graviola (soursop) | Blood sugar lowering (animals) and diabetes-medicine interaction. In animals graviola lowered blood sugar. MSK says it may add to the effect of diabetes medicines; clinical relevance is unknown. |
| Guava leaf | Blood-sugar medicines and low blood sugar. Trials reported no low blood sugar in people taking diabetes medicines, but the authors say interactions with common medicines ar… |
| Gymnema | Interaction with diabetes medicines (low blood sugar). In studies of people already taking diabetes drugs, low blood sugar episodes occurred and doses had to be adjusted. EFSA warned t… |
| Horehound | Possible effects on blood sugar and blood pressure (medicine interactions). RxList, a consumer reference, says horehound may lower blood sugar and blood pressure and so may add to diabetes and blood-pressu… |
| Irvingia (African mango seed) | Added blood-sugar lowering with diabetes medicines. MSK advises against use with diabetes medicines; a consumer drug reference rates the interaction as moderate and advises close bl… |
| Jamun (Java plum seed) | Possible extra blood-sugar lowering with diabetes medicines. Because jamun may lower glucose, it could add to the effect of insulin or diabetes tablets. |
| Job's tears (coix seed) | May lower blood sugar; diabetes medicines and surgery. A consumer reference lists a moderate interaction with diabetes medicines through possible blood sugar lowering and suggests stop… |
| Jujube | Low blood sugar and surgery. A consumer drug reference says jujube may lower blood sugar, advises care with diabetes medicines, and advises stopping at least … |
| Kudzu | Interaction with diabetes medicines and liver enzymes. MSK says animal data suggest kudzu may increase the effect of antidiabetic drugs and lab data show puerarin affects CYP2D6 and CY… |
| Lycium root bark (di gu pi) | Possible added effect with diabetes and blood pressure medicines. Because animal studies point to lower blood sugar and pressure, ask a prescriber or pharmacist before combining the bark with suc… |
| Mangosteen | Sugar content and diabetes. MSK advises people with diabetes to be cautious because of the high sugar content of mangosteen products. |
| Morinda root (ba ji tian) | Blood sugar and diabetes medicines. A consumer drug reference warns the root may raise or lower blood sugar and change how diabetes medicines work. |
| Moringa | Medicine interactions (CYP3A4, sitagliptin, diabetes medicines). Memorial Sloan Kettering reports lab data that moringa may inhibit CYP3A4 and raised rifampin levels, and an animal study in whic… |
| Mulberry leaf | Low blood sugar when combined with diabetes medicines. Taking mulberry leaf with diabetes medicines may push blood sugar too low. |
| Olive leaf | Possible added effect with blood pressure or diabetes medicines. Because trials show blood pressure and blood sugar effects, a prescriber should know about olive leaf use. No specific interactio… |
| Pennyroyal | Low blood sugar in poisoning. MSK says menthofuran lowers glucose-6-phosphatase activity in rats, causing low blood sugar, and hypoglycemia appears among publi… |
| Phellodendron | Medicine interactions (transplant drugs, liver enzymes, diabetes drugs). For berberine, Memorial Sloan Kettering reports raised cyclosporine levels in kidney-transplant adults, a tacrolimus case in a ch… |
| Prickly pear (nopal) | Low blood sugar with diabetes medicines. A consumer drug reference reports case reports of low blood sugar when prickly pear is combined with diabetes drugs; another list… |
| Psyllium | Risk: diabetes and thyroid medicines may need adjusting. The EU monograph says people with diabetes should use psyllium under medical supervision, and thyroid hormone doses may need adju… |
| Salacia | Low blood sugar with diabetes medicines. A consumer drug reference rates the combination with diabetes drugs, including insulin, as a moderate interaction because blood s… |
| Sea buckthorn | Safety: higher blood glucose in a rat study. In a 90-day rat study of a fruit extract, plasma glucose rose at the higher amounts and returned to normal after stopping. Animal… |
| Stinging nettle | Possible interaction with blood sugar medicines. A case report describes low blood sugar in a 78-year-old man taking a nettle-containing BPH remedy; the product was a mixture, so… |
| Triphala | Blood-sugar lowering and diabetes medicines. Reviews and monographs report triphala or Terminalia chebula may lower blood sugar, so combining with diabetes medicines could ca… |
| Vijaysar (Indian kino) | Low blood sugar with diabetes medicines (precaution). No human study of vijaysar with diabetes drugs was found. An animal study showed the extract plus glibenclamide lowered glucose m… |
For most herbs, good human evidence is limited. Every outcome in our herb guides is rated for how strong the evidence is, and the rating is shown next to it. Across the 414 guides, 382 herbs have no outcome rated "clinical trials support a benefit".
These are the outcomes our guides rate "clinical trials support a benefit", each with the sources the guide cites. Even here, the effect is usually for one preparation, one group of people and one outcome.
| Herb | Outcome | What the guide says | Sources |
|---|---|---|---|
| Autumn crocus (colchicum) | Gout and familial Mediterranean fever (purified colchicine drug) | The purified drug colchicine is used to prevent gout flares and familial Mediterranean fever attacks, under a prescriber. This is not evidence for the plant. | Medsafe (New Zealand): Colchicine: Prescriber Update 32(1) (2011)RxList (consumer drug reference): Colchicine: consumer drug summary (2026)Archives of Disease in Childhood: Paediatric colchicine poisoning in the UK: a 10-year retrospective case series from the National Poisons Information Service (2026) |
| Black cohosh | Menopause symptoms (overall) | Some trials of black cohosh extracts suggest relief of overall menopause symptoms, though results vary by product and study. | NCCIH, NIH: Black Cohosh (2024)Memorial Sloan Kettering Cancer Center: Black Cohosh: Purported Benefits, Side Effects and More (2022) |
| Black cohosh | Hot flushes and sweating | The EU herbal committee accepts certain dry extracts for hot flushes and excessive sweating in adult women. | European Medicines Agency (HMPC): Black cohosh (Cimicifugae rhizoma): summary for the public (2018)NCCIH, NIH: Black Cohosh (2024) |
| Cascara sagrada | Short-term relief of occasional constipation | Cascara bark is taken for occasional constipation. The EU herbal committee accepts this use for up to one week. | EMA (EU): Rhamni purshianae cortex (cascara): herbal medicinal product, summary of HMPC conclusions (2020) |
| Cascara sagrada | Stimulant effect on the bowel | Its active compounds (anthraquinones, comparable to those in senna) make the bowel move and soften stool. | EMA (EU): Rhamni purshianae cortex (cascara): herbal medicinal product, summary of HMPC conclusions (2020) |
| Chasteberry | PMS symptoms | Some studies suggest fruit extract may ease premenstrual symptoms such as breast tenderness, irritability and mood change, but the studies are of mixed quality. | NCCIH, NIH: Chasteberry (2025)EMA / HMPC: Agnus castus fruit: summary for the public (2018)PubMed: Verkaik S, et al. Treatment of premenstrual syndrome with preparations of Vitex agnus castus: systematic review and meta-analysis. Am J Obstet Gynecol (2017) |
| Chicory root | Stool frequency and softness (chicory inulin) | Chicory inulin, a fermentable fiber, increased stool frequency and softened stools in people with constipation in trials and a small meta-analysis. | Nutricion Hospitalaria: Effectiveness of inulin intake on indicators of chronic constipation: a meta-analysis of controlled randomized clinical trials (2014)Int J Food Sci Nutr: Effect of consumption of chicory inulin on bowel function in healthy subjects with constipation (RCT) (2017)Z Gastroenterol: Phytotherapeutic recommendations in medical guidelines for gastroenterological diseases: systematic review (2024) |
| Cinchona bark | Source of quinine, used for malaria | Cinchona bark is the natural source of quinine. MedlinePlus says prescription quinine is used to treat malaria under a doctor's care; it is not used to prevent it. | MedlinePlus: Quinine (Qualaquin) (2026) |
| Common sorrel | Acute viral sinus infection (as part of the five-herb extract BNO 1016) | Two pooled placebo-controlled trials in 589 adults found faster symptom improvement with a five-herb extract that includes sorrel herb. The manufacturer funded them. | Acta Oto-Laryngologica: Herbal drug BNO 1016 is safe and effective in the treatment of acute viral rhinosinusitis (2015)Rhinology: Traditional herbal medicine in the treatment of acute and chronic rhinosinusitis: a systematic review (2025) |
| Cowslip (primula) | Productive cough: thyme plus primula root combination | For certain thyme plus primula root products, the EU accepts a well-established use as an expectorant for productive cough in adults. One placebo-controlled trial of a thyme-primrose root tablet in 361 adults with acute bronchiti… | European Medicines Agency: Thymi herba and Primulae radix combination - herbal medicinal product (public summary) (2016)EMA HMPC: EU herbal monograph on Thymus vulgaris/zygis herba and Primula veris/elatior radix (EMA/HMPC/84990/2015) (2016)PubMed (Arzneimittelforschung): Kemmerich B. Thyme herb and primrose root extract combination in adults with acute bronchitis and productive cough (PMID 17966760) (2007) |
| Cranberry | Preventing recurrent urinary tract infections | Cranberry products probably lower the chance of symptomatic, lab-confirmed urinary tract infections (UTIs), mainly in women who get them repeatedly and in children. | Cochrane: Cranberries for preventing urinary tract infections (Williams et al.) (2023)NCCIH, NIH: Cranberry (2024) |
| Dragon's blood (sangre de grado) | HIV-associated non-infectious diarrhea (purified drug crofelemer) | Crofelemer, purified from Croton lechleri latex, is FDA-approved for relief of non-infectious diarrhea in adults with HIV/AIDS on antiretroviral therapy. In a trial of 374 adults, 18% responded versus 8% on placebo. | US FDA / DailyMed: MYTESI (crofelemer) delayed-release tablets, prescribing information (2020)Memorial Sloan Kettering Cancer Center: Croton lechleri (Sangre de Drago) (2019) |
| Echinacea | Short-term use for colds in EU herbal medicine (fresh purple coneflower herb, by mouth) | The EU herbal committee lists short-term prevention and treatment of common colds as a use for medicines from Echinacea purpurea herb taken by mouth, for adults and adolescents over 12. This is a statement about those particular … | EMA (EU), HMPC: Purple coneflower herb (Echinaceae purpureae herba): herbal medicinal product summary (2016)alternativemed.com: Echinacea (site page; cites HMPC monograph, LiverTox, LactMed) (2026) |
| Flaxseed | Habitual constipation | The EU recognises linseed as a herbal medicine for habitual constipation, and small trials found better bowel habits. It must be taken with plenty of fluid. | European Medicines Agency: Herbal medicine: summary for the public, Linseed (Linum usitatissimum L., semen) (2016)European Medicines Agency (HMPC): European Union herbal monograph on Linum usitatissimum L., semen (2015)Asia Pac J Clin Nutr: Flaxseed supplementation on functional constipation in a Chinese population: randomized trial (PMID 32229443) (2020) |
| Ginger | Preventing motion-sickness nausea | In the EU, powdered ginger root is a registered herbal medicine for preventing nausea and vomiting in motion sickness. US NCCIH says most studies have not shown it to be helpful. | European Medicines Agency: Zingiberis rhizoma - herbal medicinal product (public summary) (2026)NCCIH (NIH): Ginger: Usefulness and Safety (2025) |
| Ginger | Nausea and vomiting in pregnancy | NCCIH says research shows ginger supplements may help nausea in pregnancy. The EU summary and Memorial Sloan Kettering advise against use in pregnancy, so sources differ. | NCCIH (NIH): Ginger: Usefulness and Safety (2025)European Medicines Agency: Zingiberis rhizoma - herbal medicinal product (public summary) (2026)Memorial Sloan Kettering Cancer Center: Ginger: Purported Benefits, Side Effects & More (2026) |
| Guayusa | Caffeinated leaf (stimulant drink) | Guayusa leaf contains caffeine; water extracts held 19.8 to 57.7 mg per 100 mL in an Irish review, more than yerba mate extracts. | Food Safety Authority of Ireland: Substantial equivalence opinion: Ilex guayusa (2017)Molecules (Noriega et al.): Guayusa (Ilex guayusa Loes.) ancestral plant of Ecuador: history, traditional uses, chemistry, biological activity (2025) |
| Hawthorn | Added to usual care in chronic heart failure | A Cochrane review of placebo-controlled trials found that hawthorn leaf-and-flower extract, added to usual treatment, improved exercise tolerance and symptoms such as breathlessness and tiredness in adults with chronic heart fail… | Cochrane (via Europe PMC): Hawthorn extract for treating chronic heart failure (2008)NCCIH: Hawthorn (2025) |
| Ivy leaf | Expectorant for productive (chesty) cough | The EU herbal medicines committee accepts ivy leaf extracts as an expectorant, a medicine that helps bring up phlegm, for chesty coughs in adults and children from 2 years. | European Medicines Agency: Hederae helicis folium - herbal medicinal product (ivy leaf) (2017) |
| Mayapple | Source of cancer drugs (etoposide) | A 2026 abstract describes etoposide as a semisynthetic derivative of podophyllotoxin originally isolated from mayapple rhizomes. NCI lists etoposide as an approved cancer drug used with other medicines. | Metabolic Engineering Communications (abstract, Europe PMC): A yeast-based platform for etoposide production via yatein bioconversion (2026)National Cancer Institute: Etoposide (2026) |
| Monk fruit | US regulatory status (GRAS no-questions letters) | For certain highly purified monk fruit extracts and a juice concentrate, FDA has not questioned the companies' conclusions that they are generally recognised as safe under stated uses. FDA did not make its own finding. | U.S. FDA: Agency Response Letter, GRAS Notice No. GRN 000627 (2016)U.S. FDA: High intensity sweeteners (2017) |
| Mugwort | Moxibustion for breech presentation | Burning dried mugwort near an acupuncture point on the little toe probably lowers the chance of a baby being breech at birth, according to a 2023 Cochrane review. Caesarean rates probably changed little. | Cochrane: Cephalic version by moxibustion for breech presentation (2023) |
| Nasturtium (garden) | Preventing recurrent bladder infection | In two placebo-controlled trials of a nasturtium-horseradish combination, fewer recurrences of bladder infection occurred than with placebo. The newer trial's effect faded by one year, and the makers were involved. | PubMed (Albrecht et al., BMC Complement Med Ther): Nasturtium herb and horseradish root versus placebo in prophylaxis of recurrent uncomplicated cystitis (2026)PubMed (Albrecht et al., Curr Med Res Opin): Nasturtium and horseradish herbal product for preventing recurrent urinary tract infections: placebo-controlled trial (2007)IQWiG: Bladder infection: do herbal remedies help with recurrent bladder infection? (HT20-01) (2022) |
| Peppermint | Relief of IBS symptoms (enteric-coated oil capsules) | In adults with irritable bowel syndrome, enteric-coated peppermint oil capsules did better than placebo for overall symptoms and belly pain, but caused more side effects. The certainty of the evidence is very low. | Alimentary Pharmacology & Therapeutics (via Europe PMC): Systematic review and meta-analysis: efficacy of peppermint oil in irritable bowel syndrome (2022)NCCIH (NIH): Peppermint Oil (2025) |
| Peppermint | Indigestion (peppermint-plus-caraway oil combinations) | A Cochrane review found fixed peppermint and caraway oil combinations probably gave a large improvement in indigestion symptoms at four weeks (moderate certainty). Peppermint oil alone has not been shown to help. | Cochrane (via Europe PMC): Non-Chinese herbal medicines for functional dyspepsia (2023)NCCIH (NIH): Peppermint Oil (2025) |
| Psyllium | Easing habitual constipation | Psyllium husk is a bulk-forming fiber. It absorbs liquid in the gut and makes stool bulkier and easier to pass. | European Medicines Agency, HMPC: Community herbal monograph on Plantago ovata Forssk., seminis tegumentum (EMA/HMPC/199774/2012) (2013)PubMed (PMID 35816465): The Effect of Fiber Supplementation on Chronic Constipation in Adults: An Updated Systematic Review and Meta-Analysis of Randomized Controlled Trials (2022)MedlinePlus (NLM): Psyllium (2024) |
| Psyllium | Softening stool when straining is painful | The EU committee supports ispaghula husk where soft stool is wanted, for example with anal fissures, haemorrhoids, or after anal or rectal surgery. | European Medicines Agency, HMPC: Community herbal monograph on Plantago ovata Forssk., seminis tegumentum (EMA/HMPC/199774/2012) (2013)European Medicines Agency: Ispaghula seed (Plantaginis ovatae semen): herbal medicinal product (public summary) (2014) |
| Psyllium | Lowering LDL cholesterol (lab marker) | Meta-analyses of trials found lower LDL and total cholesterol with psyllium; triglycerides and HDL did not change significantly in the 2025 analysis. | PubMed (PMID 30239559): Effect of psyllium (Plantago ovata) fiber on LDL cholesterol and alternative lipid targets: a systematic review and meta-analysis of randomized controlled trials (2018)PubMed (PMID 41366295): Psyllium supplementation and lipid profiles: systematic review and dose-response meta-analysis of randomized controlled trials (2025)US eCFR, 21 CFR 101.81 and 101.17(f): Health claims: soluble fiber from certain foods and coronary heart disease (2024) |
| Pygeum | Regulatory status in the EU | The EU herbal committee lists a specific bark extract as a traditional herbal medicine for relief of lower urinary tract symptoms related to BPH, after a doctor has excluded serious conditions. It is based only on long-standing u… | European Medicines Agency (HMPC): European Union herbal monograph on Prunus africana (Hook f.) Kalkm., cortex (2016) |
| Rhubarb root | Short-term relief of occasional constipation | In the EU, rhubarb root is a recognised medicine for short-term relief of occasional constipation, for no more than one week. It works as a stimulant laxative. | European Medicines Agency: Rhei radix - herbal medicinal product (public summary) (2020)Memorial Sloan Kettering Cancer Center: Rhubarb: Purported Benefits, Side Effects & More (2022) |
| Sarpagandha (Indian snakeroot) | Lowering high blood pressure (purified reserpine) | A Cochrane review of 4 trials (237 people) found the drug reserpine lowered the upper blood-pressure number by about 8 mmHg compared with placebo. This is the purified drug, not the whole root. | Cochrane: Blood pressure-lowering efficacy of reserpine for primary hypertension (2016)alternativemed.com: Drugs from Ayurvedic sources (site page) (2026) |
| Saw palmetto | Regulatory status in the EU | The EU herbal committee classes a hexane extract as well-established use for BPH symptoms in men, and an ethanol extract as traditional use only. | European Medicines Agency (HMPC): Sabalis serrulatae fructus - herbal medicinal product summary |
| Senna | Short-term relief of occasional constipation | Senna leaf is a stimulant laxative that makes the bowel muscles move stool along. EU and UK health bodies accept it for short-term constipation. | NHS: Senna: a laxative medicine to treat constipation (2026)EMA (HMPC): Sennae folium (senna leaf): summary of HMPC conclusions (2020) |
| Senna | Constipation in older adults and people with long-term constipation | In studies reviewed by the EU committee, mostly in older adults with chronic or severe constipation, senna taken with fibre worked at least as well as comparators such as lactulose. | EMA (HMPC): Sennae folium (senna leaf): summary of HMPC conclusions (2020) |
| Senna | Chronic idiopathic constipation (guidelines) | A 2023 US guideline panel made only a conditional recommendation for senna in chronic idiopathic constipation, with stronger recommendations for other medicines. | alternativemed.com: Senna page (cites EMA monograph 2018, AGA-ACG 2023 guideline, Rao 2022 review, LiverTox 2020; not re-read directly) (2026) |
| St. John's wort | Mild to moderate depression (specific extracts) | Trials of particular St. John's wort extracts found them better than placebo and similar to standard antidepressants for mild to moderate depression. Results do not carry over to every product. | NCCIH (US NIH): St. John's Wort: Usefulness and Safety (2026)NHS (UK): Clinical depression: treatment (2026)alternativemed.com: St. John's wort page (cites Cochrane 2008, Apaydin 2016, Nicolussi 2020, LiverTox) (2026) |
| Sweet wormwood (Artemisia annua) | Source plant of artemisinin medicines | The plant is the origin of artemisinin, from which prescription malaria combination medicines were developed. | Memorial Sloan Kettering Cancer Center: Artemisia annua (2026)World Health Organization: The use of non-pharmaceutical forms of Artemisia (2019) |
| Valerian | One dry ethanolic root extract: well-established use in the EU | The EU committee accepts one specific dry ethanolic root extract for mild nervous tension and sleep disorders, based on clinical studies. | EMA / HMPC: Valerianae radix (valerian root): herbal medicinal product summary for the public (2026) |
| Willow bark | Short-term low back pain | In two trials, willow bark extract standardized to 120 mg or 240 mg salicin a day was probably better than placebo for short-term pain. The EU herbal committee rates the dry extract as well-established use for short-term low back… | Cochrane: Herbal medicine for low-back pain (2014)EMA: Willow bark: herbal medicinal product, summary for the public (2017) |
| Yerba santa | Natural flavoring in food | In the United States, yerba santa is on the FDA list of permitted natural flavoring substances, with no limitation listed. This is a food-additive rule, not approval as a medicine. | US government (eCFR): 21 CFR 172.510 Natural flavoring substances (2026) |
How many outcomes each guide rates in each evidence group. Open a guide for the individual outcomes, what was found (including negative results) and the sources.
Herb Evidence and Safety at a Glance: Table of Every Profile · Herb Research & Evidence · Common Names to Scientific Names: A Quick Reference Table
The guides cite 2,748 distinct sources. These are the ones cited most often, and the main places to check any herb claim yourself.
The same plant can be a tea, a tincture, a capsule of powder or a concentrated extract, and these are not interchangeable. A study of one preparation does not tell you what another does. This tab shows which forms each guide describes, and how to judge product quality.
Roots, leaves, flowers, seeds and bark can contain different compounds, so the part named on the label matters. Plant Parts Used in Herbal Products: Leaf, Root, Seed, Flower, Bark
For each kind of preparation, the herbs whose guides describe it. The guides say which form was actually studied. Detailed preparation instructions are in Herbal Teas & Extracts, so they are not repeated here.
Read: Herbal Teas, Infusions and Decoctions Explained
Read: Tinctures, Fluid Extracts and Glycerites: What the Words Mean · Herbal Syrups, Lozenges and Gummies
Read: Herbal Capsules, Tablets and Powders
Read: Herbal Capsules, Tablets and Powders
Read: Standardized Herbal Extracts: Marker Compounds and Extract Ratios · Standardization and Marker Compounds for Herbs
Read: Topical Herbal Products: Salves, Oils, Creams and Poultices
Read: Fresh, Dried and Freeze-Dried Herbs: Does It Matter? · Fresh vs Dried vs Extract: Which Form Was Studied?
A whole herb (fresh, dried or powdered) contains everything in the plant part, in amounts that vary. A standardized extract is made to contain a stated amount of one or more marker compounds, which makes batches more consistent but is not the same as the whole herb.
An extraction ratio such as 4:1 says how much plant material was used per unit of extract. It does not by itself say how much active compound a capsule holds or whether the product works. A marker compound is something measured for quality control; it is not always the compound that causes any effect.
Amounts and duration. We do not give universal dose recommendations. Where a source reports the amount and length of use tested for a named preparation, the herb's guide gives it in that context; an amount studied in one product does not carry over to another, or to food-level use.
Absorption. Some active constituents are poorly absorbed, which is why concentrated or specially formulated products exist (curcumin is the best-known case). Better absorption can also raise the risk of side effects.
A good label names the plant by its scientific name, says which part is used, and states the amount and form. Third-party testing can check identity, strength and contamination, but a seal is not a guarantee of safety or benefit.
Forms & preparations: the full guide · Herbal Teas & Extracts
A dietary supplement containing one or more herbs, sold as teas, extracts, tablets, capsules, powders or other forms. [1]
Not automatically. Some interact with prescription medicines, and some have been linked to liver injury. See Safety. [1]
It depends on the herb and the goal, and for many the evidence is limited or mixed. See by wellness goal.
Any plant or plant part used for health rather than as food: leaves, roots, flowers, seeds, bark or berries, sold as teas, extracts, capsules, powders or topical products. Each herb here has one guide with its scientific name, traditional uses, research, safety and forms. [2]
Yes. St. John's wort, for example, can weaken many prescription medicines, and some herbs add to the effect of blood thinners or diabetes medicines. Tell your pharmacist and clinician about every herb you take. See herb-drug interactions and the Safety tab. [3]
Yes. Some herbs can affect bleeding or interact with anesthesia, and many surgical teams ask people to stop herbal products beforehand. Ask your team how long. See herbs before and after surgery.
Often there are not enough safety data, so official sources usually advise asking a clinician first. See herbs during pregnancy, while breastfeeding and for children.
A whole herb is the plant part itself. A standardized extract is made to contain a stated amount of one or more marker compounds. A study of one does not carry over to the other. See the Forms & Quality tab and standardized extracts explained.
It varies by herb and by outcome, and for many herbs it is early, mixed or limited to lab and animal studies. Each guide rates every outcome. See the Evidence tab. [1]
A guide is written and sourced one herb at a time and covers evidence, safety and forms. A record in the Herbs Database in the Research Library is reference data with linked studies and is not a reviewed guide.
In the United States call Poison Help at 1-800-222-1222. For collapse, seizure or trouble breathing, call your local emergency number. See the Safety tab.
No. It covers herbs used for health. Culinary herb pages are not part of this section.
Complete A to Z directory of herbs with guides
Content last updated . The tabs from Health Benefits onward are compiled automatically from the evidence ratings and sources in each herb's guide (last data update October 26, 2026). This section has not been medically reviewed.
