Explore Herbs & Botanicals
Herbs with a sourced guide: scientific names, plant part used, and whether the herb has medicine interactions. The full herb database is in the Research Library.
Content last updated . This page has not been medically reviewed.
Safety first. Supplements can cause side effects and interact with medicines. Read mushroom safety and interactions before you use any mushroom product.
This directory lists herbs that have a written, sourced guide. Herbs without a guide are listed but not linked, and we do not publish thin placeholder pages. The complete herb database (thousands of records, many from traditional Chinese medicine sources) is the Herbs Database in the Research Library.
Directory
| Herb | Scientific name | Plant part | Key caution |
|---|---|---|---|
| Chamomile | Matricaria chamomilla (German) | Flower | Ragweed-family allergy; warfarin [1] |
| Echinacea | Echinacea purpurea and others | Aerial parts, root | Allergy [2] |
| Elderberry | Sambucus nigra | Berry | Raw berries poisonous [3] |
| Garlic | Allium sativum | Bulb | Bleeding [4] |
| Ginger | Zingiber officinale | Rhizome | Heartburn [5] |
| Ginkgo | Ginkgo biloba | Leaf extract (seed toxic) | Bleeding [6] |
| Green tea | Camellia sinensis | Leaf | Extract liver injury [7] |
| Milk thistle | Silybum marianum | Seed extract | Allergy; quality [8] |
| Saw palmetto | Serenoa repens | Berry | Pregnancy [9] |
| St. John's wort | Hypericum perforatum | Flowering tops | Many interactions [10] |
| Turmeric | Curcuma longa | Rhizome | Liver [11] |
| Valerian | Valeriana officinalis | Root, rhizome | Withdrawal; sedatives [12] |
Names were checked against GBIF on 2026-10-22. [13] Plant part follows the NIH summaries. This is a browsing aid; one herb can involve several parts with different risks.
Elsewhere on the site
Ashwagandha, rhodiola, ginseng, eleuthero, holy basil and similar herbs sit in Adaptogens. Mushrooms are in Mushrooms. Essential oils are in Essential Oils & Aromatherapy.Evidence snapshot
| Herb | Records tagged as randomized controlled trials | Records tagged as any clinical trial | All PubMed records that mention it | Check it yourself |
|---|---|---|---|---|
| Turmeric / curcumin | 597 | 705 | 31,898 | PubMed search |
| Elderberry | 18 | 29 | 1,372 | PubMed search |
| Milk thistle | 147 | 202 | 4,909 | PubMed search |
| Ginger | 277 | 312 | 6,632 | PubMed search |
| Green tea | 546 | 669 | 20,779 | PubMed search |
| Garlic | 223 | 281 | 9,502 | PubMed search |
| Echinacea | 69 | 93 | 1,546 | PubMed search |
| Chamomile | 101 | 116 | 1,843 | PubMed search |
| Saw palmetto | 85 | 103 | 669 | PubMed search |
| Valerian | 62 | 77 | 966 | PubMed search |
| Ginkgo | 337 | 413 | 5,886 | PubMed search |
| St. John's wort | 167 | 244 | 4,195 | PubMed search |
| Aloe vera | 128 | 148 | 2,944 | PubMed search |
| Cranberry | 155 | 182 | 2,233 | PubMed search |
| Black cohosh | 49 | 62 | 705 | PubMed search |
| Passionflower | 19 | 21 | 287 | PubMed search |
| Lemon balm | 51 | 56 | 898 | PubMed search |
| Cinnamon | 110 | 129 | 5,992 | PubMed search |
| Fenugreek | 50 | 59 | 2,051 | PubMed search |
| Feverfew | 9 | 14 | 442 | PubMed search |
| Hawthorn | 47 | 53 | 1,868 | PubMed search |
| Boswellia / frankincense | 87 | 101 | 1,358 | PubMed search |
| Kava | 38 | 42 | 884 | PubMed search |
| Nettle | 26 | 33 | 1,001 | PubMed search |
| Hibiscus | 41 | 52 | 2,209 | PubMed search |
| Moringa | 34 | 40 | 3,315 | PubMed search |
Counted 2026-10-22 using NCBI E-utilities. Counts include studies of extracts, blends and non-health topics, and a trial can find no effect. A higher count means more human research has been indexed, not that something works.
Names are in standard scientific form and were checked against NCBI Taxonomy and the GBIF checklist on October 22, 2026. Plain names show as links when a guide has been published, and as dashed labels when a guide is in preparation. Each mushroom has one guide, even when it appears in more than one group.
Popular Herbs with Guides
Herbs with the most search interest that have a sourced guide.
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Turmeric
Turmeric and curcumin: what NIH says about osteoarthritis, liver and other uses, why bioavailable curcumin products have been linked to liver damage, and how forms differ.
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Elderberry
Elderberry: what NIH says about colds and flu, why raw or unripe elderberries are poisonous, and what is unknown about other uses.
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Milk Thistle
Milk thistle and silymarin: what NIH says about liver disease, blood sugar and other uses, side effects, allergy risks and product quality concerns.
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Ginger
Ginger: what NIH says about nausea in pregnancy, motion sickness, menstrual cramps and osteoarthritis, plus side effects and safety in pregnancy.
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Green Tea
Green tea and green tea extract: what NIH says about cholesterol, weight and cancer research, and why extract supplements have been linked to liver injury and drug interactions.
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Garlic
Garlic: what NIH says about cholesterol, blood pressure, blood sugar and immune claims, bleeding risk before surgery, and skin burns from raw garlic.
Calming, Immune & Other Herbs
More herbs with a sourced guide.
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Echinacea
Echinacea: what NIH says about colds, which species and parts are used, allergic reactions, and possible medicine interactions.
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Chamomile
Chamomile: what NIH says about anxiety, sleep and colic, German versus Roman chamomile, allergy risks and possible interactions with warfarin and birth control pills.
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Valerian
Valerian: what NIH says about sleep (including a guideline against use for chronic insomnia), safety limits, withdrawal effects and liver reports.
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Ginkgo
Ginkgo: what NIH says (including a large trial that found no effect on dementia), bleeding risk with anticoagulants, and the toxicity of ginkgo seeds.
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St. John's Wort
St. John's wort: what NIH says about mild to moderate depression, and its dangerous interactions with antidepressants, birth control, transplant and other medicines.
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Saw Palmetto
Saw palmetto: what NIH says (probably not helpful for enlarged prostate symptoms), what is known about hair loss, and safety.
Planned (Not Yet Written)
Herbs on our list. They are not linked until a sourced guide exists.
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Aloe Vera
Aloe vera.
Guide in preparation
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Cranberry
Vaccinium macrocarpon.
Guide in preparation
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Black Cohosh
Actaea racemosa.
Guide in preparation
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Passionflower
Passiflora incarnata.
Guide in preparation
-
Lemon Balm
Melissa officinalis.
Guide in preparation
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Peppermint
Mentha x piperita. See the Essential Oils section for the oil.
Guide in preparation
-
Hibiscus
Hibiscus sabdariffa.
Guide in preparation
-
Fenugreek
Trigonella foenum-graecum.
Guide in preparation
About the PubMed counts: they come from a text search of PubMed (NCBI E-utilities) for the scientific and common names plus the "randomized controlled trial" publication type. They include studies of extracts, blends and non-health uses, and a trial can find no effect. A count shows how much human research has been indexed, not whether something works.
References
- National Center for Complementary and Integrative Health (NIH). Chamomile: Usefulness and Safety. Page last updated November 2024.
- National Center for Complementary and Integrative Health (NIH). Echinacea: Usefulness and Safety. Page last updated November 2024.
- National Center for Complementary and Integrative Health (NIH). Elderberry: Usefulness and Safety. Page last updated November 2024.
- National Center for Complementary and Integrative Health (NIH). Garlic: Usefulness and Safety. Page last updated February 2025.
- National Center for Complementary and Integrative Health (NIH). Ginger: Usefulness and Safety. Page last updated February 2025.
- National Center for Complementary and Integrative Health (NIH). Ginkgo: Usefulness and Safety. Page last updated February 2025.
- National Center for Complementary and Integrative Health (NIH). Green Tea: Usefulness and Safety. Page last updated February 2025.
- National Center for Complementary and Integrative Health (NIH). Milk Thistle: Usefulness and Safety. Page last updated February 2025.
- National Center for Complementary and Integrative Health (NIH). Saw Palmetto: Usefulness and Safety. Page last updated April 2025.
- National Center for Complementary and Integrative Health (NIH). St. John's Wort: Usefulness and Safety. Page last updated May 2025.
- National Center for Complementary and Integrative Health (NIH). Turmeric: Usefulness and Safety. Page last updated April 2025.
- National Center for Complementary and Integrative Health (NIH). Valerian: Usefulness and Safety. Page last updated May 2025.
- GBIF Secretariat. GBIF Backbone Taxonomy. Names checked 2026-10-22 through the GBIF species match service.