Herbs & Botanicals · Poisonous plant, injectable cancer add-on

Mistletoe

Q: What is European mistletoe?

A semi-parasitic evergreen plant (Viscum album) that grows on trees. In Europe, injectable extracts are prescription medicines used as an add-on in cancer care. The raw plant and berries are poisonous.

Q: Can mistletoe cure cancer?

No. The best-designed trials do not show that it helps people live longer, and the FDA has not approved it for cancer. It should never replace standard treatment. Ask your cancer team before using any mistletoe product.

Q: Does mistletoe help people live longer?

Not reliably. All studies pooled looked good for mistletoe, but the better-designed randomised studies did not show a significant benefit, and their range was very wide.

Q: Does it improve quality of life?

It may, with low certainty. Pooled studies suggest a medium-sized improvement, and breast cancer trials were rated moderate certainty. But most studies are open-label, and a placebo-controlled pancreatic cancer trial found no benefit.

Q: Is mistletoe tea safe?

No. Poison Control links serious poisonings and deaths to European mistletoe, usually concentrated preparations such as tea. Tea is not the studied injectable extract.

Q: What if a child or pet eats a berry?

Call a poison centre or emergency services (US poison help line: 1-800-222-1222). American mistletoe seems milder, but you cannot assume the plant is American.

Q: What are the side effects of the injections?

Soreness at the site, headache, fever, chills and tiredness are common. A few severe allergic reactions have been reported, including anaphylaxis. Call emergency services for trouble breathing or swelling after an injection.

Q: Can I use mistletoe with immunotherapy or if I have an autoimmune disease?

Ask your specialist. Small observational studies, some linked to mistletoe makers, found no extra problems, but they cannot rule out interactions.

Q: Is it safe in pregnancy or breastfeeding?

No safety information was found. Treat it as unknown and ask a doctor.

Q: Does it affect the liver?

NCI reports reversible liver injury only with high doses of a lab-made lectin that is not sold. We found no case with commercial extracts, but the LiverTox page was not read. Ask a doctor if you have liver disease.

Viscum album · also called European mistletoe, mistletoe, Mistel (German), Iscador and Helixor (brands of extract)

European mistletoe is a plant that grows on trees. Its berries and leaves are poisonous, and tea made from it has been linked to deaths. In Europe, injectable extracts are prescribed as an add-on in cancer care. Reviews find the evidence for living longer weak, with a possible small quality-of-life benefit that is still uncertain. It is not a cure, and it should never replace standard treatment.

General information, not medical advice. Last substantive update October 25, 2026 · Not medically reviewed. A named clinician has not signed off on this page. How this page is made

About Mistletoe

European mistletoe is a poisonous plant whose injectable extracts are used in Europe as an add-on in cancer care. The evidence that it helps people live longer is weak, there may be a small quality-of-life benefit, and the plant and tea are dangerous.

What it is

European mistletoe (Viscum album) is a woody, evergreen plant that grows on the branches of trees and takes water and minerals from them. It is not the same plant as American mistletoe (Phoradendron), which has the same common name and seems less toxic.

In Europe, injectable extracts of the plant are prescription medicines used as an add-on in cancer care. Their main active parts are thought to be mistletoe lectins and viscotoxins, plus sugars and plant chemicals. The make-up of an extract changes with the host tree, harvest time and maker. The injectable product is not the same thing as the raw plant, berries or tea.

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What the research shows

Almost all the research is on injected extracts as an add-on to cancer treatment. The Cochrane review (2008) found the evidence for longer survival weak and the evidence for better quality of life during breast cancer chemotherapy in need of confirmation. A 2019 review found that high-quality studies did not show a survival benefit, and a 2024 analysis showed the apparent benefit depends on study quality (all studies pooled hazard ratio 0.61; higher-quality randomised studies 0.78, not significant).

Quality of life and tiredness look better in pooled analyses, but those studies are mostly open-label with a high risk of bias, and some reviewers are linked to mistletoe makers. A 2026 double-blind placebo-controlled trial in 290 people with advanced pancreatic cancer found no quality-of-life benefit. Around surgery, seven randomised trials found no difference in death or recurrence.

Lab studies show mistletoe compounds kill cells and stimulate immune cells. That is not proof of benefit in people.

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At a glance

Traditional uses history, not proof

Epilepsy, asthma and high blood pressure (folk use)
Arthritis and rheumatism
Add-on injections in cancer care in German-speaking countries for about 100 years

Studied for research

Survival in cancer, low
Quality of life in cancer, low (breast cancer, moderate)
Cancer-related tiredness, low
Around cancer surgery, low (no difference)
Immune blood markers, insufficient
Folk uses, insufficient

Main compounds

Mistletoe lectins
Viscotoxins
Polysaccharides
Flavonoids and phenolic acids

Common forms

Prescription injectable extracts (Iscador, Helixor, abnobaVISCUM)
Leafy twig / herb
Tea (dangerous)
Berries (poisonous)

Research links: NCI: Mistletoe Extracts (patient version) · NCI: Mistletoe Extracts (health professional) · Poison Control: Is mistletoe poisonous? · Cochrane review: Mistletoe therapy in oncology (PubMed) · Study quality and mistletoe survival meta-analysis (PubMed) · MISTRAL pancreatic cancer trial (PubMed) · Research Library · Genes & Biomarkers Library

The plant and its history

Accepted scientific name: Viscum album L.
Naming authority: L. (GBIF accepted species, key 2889828, retrieved 2026-10-25)
Synonyms: Not listed from the GBIF match used; synonym list not retrieved.
Common names: European mistletoe (English); Mistletoe (English); Mistel (German); Visci albi herba (Latin (pharmacy name))
Botanical family: Viscaceae (mistletoe family) in GBIF. Mistletoes are semi-parasitic: they take water and minerals from the host tree.
Classification: Plantae > Santalales > Viscaceae (GBIF); NCI uses Loranthaceae; some systems use Santalaceae (not checked) > Viscum > Viscum album
Native range: Not verified from a source read.
Habitat: Grows on host trees. NCI lists apple, oak, maple, elm, pine and poplar; host tree affects the chemistry.
What the plant looks like: Roots: Not studied in the sources read.; Stems: Evergreen woody shrub growing on tree branches (Nazaruk 2016: evergreen hemiparasitic shrub).; Leaves: Leafy twig is the usual plant material (leafy twig / herb).; Flowers: Not described in the sources read.; Fruit: Berries are poisonous (NCI says plants and berries are considered poisonous); colour not described in the sources read.
Cultivation: Not verified.
Harvest and processing: NCI: composition depends on host tree, time of year picked and extraction. Fermented (Iscador-type) and unfermented (Helixor-type) aqueous extracts exist; some are prepared by homeopathic principles.
Look-alikes and adulterants: Name: American mistletoe (Phoradendron leucarpum, also called P. serotinum or P. flavescens); Note: A different plant with the same common name. Poison Control says it is much less toxic than European mistletoe; the 92-case review is about this species, not Viscum album. GBIF key 2889887.; Name: Korean mistletoe (Viscum album var. coloratum); Note: NCI mentions extracts of this variety in lab studies; trial results for it are not covered here.
Sustainability and conservation: Not assessed in the sources read.

Traditional use and history history, not clinical proof

Tradition or era	Documented use	Source
Traditional use (long-standing, per NCI)	Used for hundreds of years for epilepsy, asthma, high blood pressure, headaches, menopausal symptoms, infertility, skin problems, arthritis and rheumatism. Traditional use is not proof it works.	s-nci-pdq-pt
Add-on in cancer care in German-speaking countries	Injected extracts used for about 100 years (Oei 2019 review) and among the most prescribed cancer-related drugs in some European countries (NCI).	p31118962
Regulatory	Injectable extracts are prescription drugs in Europe and are not approved for cancer in the US. The EMA position is summary-only (not verified).	s-nci-pdq-hp

Traditional use shows how a plant was used. It does not show that a supplement works or is safe today.

What is inside, and how it may work

What the plant contains and how those compounds act in cells and animals. Laboratory and animal mechanisms are not proven effects in people.

Main compounds

Compound	Family	Where it is concentrated	Activity studied	Level of evidence
Mistletoe lectins (viscumin, ML I-III)	protein-carbohydrate molecule that binds cell surfaces	Varies by host tree; Iscador Quercus is lectin-rich, Iscador Pinus is lectin-poor	Bind to cells and trigger chemical changes in immune cells and cell death in the lab (NCI). In 47 healthy volunteers, the lectin-rich extract raised TNF-alpha release by blood cells. ^{16 8}	Laboratory research
Viscotoxins (for example viscotoxin A3)	small cationic peptides (thionins), about 5 kDa	Not stated in the sources read	Form ion channels in membranes and show cell-killing and antimicrobial activity in the lab (NMR study). ^{20 16}	Laboratory research
Polysaccharides	carbohydrates	Not stated	Named by NCI as one of three components that may account for mistletoe's immune effects. Details not read. ¹⁶	Laboratory research
Flavonoids, phenolic acids, triterpenes	polyphenols and terpenoids	Not stated	Antioxidant and anti-inflammatory activity in the lab; a review says these may lower blood pressure. ¹⁷	Laboratory research
Quercetin (example flavonoid) PubChem 5280343	flavonol	Not stated	PubChem record only. Whether quercetin is a major mistletoe constituent was not confirmed from a source read; the review names flavonoids as a class. ^{14 17}	Laboratory research

Mechanisms, receptors and pathways

Target or pathway	Gene or receptor	What was found	Level
Immune-cell activation and cytokine release	TNF, IL-5, IL-13	In healthy volunteers the lectin-rich extract raised TNF-alpha release by blood cells; the viscotoxin-rich extract lowered IL-5 and IL-13. Placebo changes also occurred (human, lab-measured). ⁸	Human data
Cell membrane disruption by viscotoxin		Viscotoxin A3 forms ion channels and can break up membranes in lab models (test-tube NMR study). ²⁰	Laboratory research
Direct cell killing and immune stimulation by lectins, viscotoxins and polysaccharides		NCI summarises lab and animal work: induces cell death and stimulates immune cells in vitro and in vivo (animals). These findings are not proof of benefit in people. ¹⁶	Animal research

Absorption, metabolism and elimination

Absorption: No human absorption data found in the sources read for any mistletoe extract.
Distribution: Not found.
Metabolism: Not found; no drug-metabolising enzyme studies read.
Elimination: Not found.
Bioavailability: Unknown.

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Isolated compounds versus whole extracts

The studied injectables are whole extracts of the plant, and their content depends on host tree and method. Lectin-rich and viscotoxin-rich extracts behaved differently in healthy volunteers. A lab-made lectin (rViscumin / aviscumine) has been studied separately and is not an extract (NCI). Whole-plant home preparations are poisonous.

Nutritional composition

A nutrient table does not apply. Mistletoe is not a food and is poisonous if eaten.

10benefits and uses looked at

27studies and sources checked

Moderate certaintybest evidence rating found

5lab markers tracked in trials

1 moderate certainty5 low certainty2 very low certainty2 not enough evidence

What is Mistletoe good for?

The main proposed uses and how strong the human evidence is for each. "Low" means small or weak studies; "insufficient" means too little evidence to judge. These are all about injected extracts used under a cancer team, not about eating the plant.

Living longer with cancer (survival)Low certaintyReviews that looked at survival found little reliable benefit. Pooling every study gave a better result for mistletoe, but in the better-designed randomised studies the benefit was not significant and the range was very wide. The Cochrane review called the evidence weak. Mistletoe is not a cancer treatment. Survival with non-fermented extractsVery low certaintyOne pooled analysis of non-fermented extracts found a possible benefit, but the studies were at moderate to high risk of bias and the result did not hold when active treatments were the comparison. Advanced pancreatic cancerLow certaintyAn older open-label trial of 220 people reported longer survival. A newer, larger double-blind placebo-controlled trial (290 people) found no benefit for quality of life and its authors saw no reason to recommend mistletoe. Quality of life in cancerLow certaintyPooled studies show a medium-sized improvement in self-rated quality of life, but most studies had a high risk of bias, and the best-controlled trial in pancreatic cancer found none. Quality of life in breast cancerModerate certaintyNine randomised trials point to better quality of life during breast cancer treatment. The reviewers rated the certainty moderate for randomised trials. Blinding is difficult with injections. Cancer-related tirednessLow certaintyRandomised trials pooled to a moderate reduction in fatigue, with high risk of bias. The review has links to a mistletoe maker. Quality of life after gastric cancer surgeryVery low certaintyOne small pilot of 32 people suggested better quality of life and less diarrhoea. Too small to rely on. Around cancer surgeryLow certaintySeven randomised trials found no difference in death or in cancer coming back. Immune blood markersNot enough evidenceSome blood immune markers change after injections, but the changes are inconsistent and have not been linked to better health. Old folk uses (epilepsy, asthma, blood pressure, arthritis)Not enough evidenceListed as traditional uses by the NCI. No human trial was found. Do not try home preparations.

Benefits, one by one

Each card is a research question, not a promise. Tap a goal to filter. Open a card to see the studies, doses and limits.

Overall survival in cancer (all reviews)

Low certainty

Most reviews that looked at living longer found no reliable benefit once study quality was taken into account. Low-quality studies look better than high-quality ones.

5 studiesInjected Viscum album extracts from many makers and host trees (Iscad…

Studies, doses and limits

What the trials found

Cochrane (2008, 21 randomised trials, 3484 people): 6 of 13 survival trials showed some benefit, but none was of high quality; two trials (melanoma, head and neck) suggested no survival gain. Freuding 2019 (28 publications): most studies showed no effect and 'especially high quality studies do not show any benefit'. Hofinger 2024 pooled 28 studies (28,298 patients): overall HR 0.61 in favour of mistletoe, but randomised studies at lower risk of bias gave HR 0.78 with a very wide interval (0.30 to 2.00). NCI says reports of improved survival are common but many studies had major weaknesses.

Results

Not shown to help people live longer once study quality is considered. The apparent benefit shrinks or disappears in the better-designed studies.

Effect sizes as reported

Hofinger 2024: all studies HR 0.61 (95% CI 0.53-0.70); higher-quality randomised studies HR 0.78 (0.30-2.00, not significant).

Why this rating

The reviewers themselves (Cochrane, Freuding 2019, Hofinger 2024) say the better the study, the smaller the benefit. We rate the evidence low because the best-quality trials do not confirm benefit, and we do not rate it 'against' because the studies are few, differ widely and have wide intervals.

Form and dose studied

Injected Viscum album extracts from many makers and host trees (Iscador, Helixor, abnobaVISCUM and others), usually added to standard cancer treatment. Products and schedules differ so much that one review found no rules linking product to cancer type (Staupe 2023). No dose advice is given here.

Who was studied

Adults with many types of cancer (breast, pancreatic, colorectal, lung, melanoma, head and neck and others).

Limits

Mixed cancer types and products; most studies open-label (no placebo); poor reporting. Mistletoe is not a cure for cancer and should never replace standard treatment.

Why researchers looked

Injected mistletoe is widely prescribed in Europe, and many people ask whether it helps people with cancer live longer.

Traditional use

Injected mistletoe extracts have been used as an add-on to cancer care in German-speaking countries for about 100 years (Oei 2019 review) and are widely prescribed in parts of Europe (NCI).

Proposed mechanism Laboratory research

In the lab, mistletoe lectins and viscotoxins kill cells and stimulate immune cells. Lab results in dishes and animals do not show that the injected extract helps people with cancer.

A proposed mechanism does not show that the effect happens in people.

Injected extracts are a prescription medicine used under a cancer team, not a food or a tea. Eating the plant or berries, or drinking mistletoe tea, is dangerous and is a different thing from the studied extracts. See the safety section.

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Survival with non-fermented mistletoe extract (one meta-analysis)

Very low certainty

One meta-analysis of a subgroup of products found a longer survival, but it did not hold when active treatments were the comparison, and the studies were at moderate to high risk of bias.

2 studiesNon-fermented mistletoe extracts (several makers), injected.

Studies, doses and limits

What the trials found

Loef 2022 pooled 11 randomised trials and 8 non-randomised studies of non-fermented extracts. For randomised trials the pooled hazard ratio for overall survival was 0.81 (95% CI 0.69 to 0.95). When active comparators were added to the analysis, the estimates were no longer significant. Risk of bias was moderate (randomised) to high (non-randomised).

Results

Suggests a possible survival benefit for non-fermented extracts, but the authors themselves say high-quality randomised trials are needed to confirm it.

Effect sizes as reported

HR 0.81 (95% CI 0.69-0.95) for randomised trials.

Why this rating

Moderate to high risk of bias, heterogeneity, result depends on the comparator, and it conflicts with the higher-quality-study analysis of Hofinger 2024. We rate it very low.

Form and dose studied

Non-fermented mistletoe extracts (several makers), injected.

Who was studied

Cancer patients of many types.

Limits

Heterogeneous studies; one analysis; not confirmed by placebo-controlled trials of the same kind.

Why researchers looked

Mistletoe makers use different methods (fermented or not). This analysis asked whether non-fermented extracts work on their own.

Traditional use

Injected mistletoe extracts have been used as an add-on to cancer care in German-speaking countries for about 100 years (Oei 2019 review) and are widely prescribed in parts of Europe (NCI).

Proposed mechanism Laboratory research

In the lab, mistletoe lectins and viscotoxins kill cells and stimulate immune cells. Lab results in dishes and animals do not show that the injected extract helps people with cancer.

A proposed mechanism does not show that the effect happens in people.

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Advanced pancreatic cancer (two randomised trials that disagree)

Low certainty

An older open-label trial reported longer survival; a newer, larger placebo-controlled trial found no benefit to quality of life.

3 studiesMistletoe extract by injection under the skin (products not named in …

Studies, doses and limits

What the trials found

Tröger 2013 (220 people, one centre, open-label, interim analysis): median survival 4.8 months with injected mistletoe versus 2.7 months with no anticancer treatment (HR 0.49, p < 0.0001). The control group received no anticancer therapy. MISTRAL (Wode 2026; 290 people, 9 centres, double-blind, placebo-controlled): no significant differences in quality of life or weight, similar care costs, and no effect on blood markers except more eosinophils. The authors saw 'no clinical reason to recommend' mistletoe extract in advanced pancreatic cancer. NCI's patient page cites the 2013 trial as showing improved survival.

Results

Mixed. The older open-label trial favoured mistletoe on survival; the newer double-blind, placebo-controlled trial found no benefit on quality of life. The two trials measured different things, so they do not directly cancel out.

Effect sizes as reported

Tröger 2013: median survival 4.8 vs 2.7 months, adjusted HR 0.49. MISTRAL 2026: no significant difference in quality of life.

Why this rating

One open-label interim analysis with a no-treatment control, versus one well-designed placebo-controlled trial with a negative result. The survival result of MISTRAL was not in the abstract we read, so we rate the pair low.

Form and dose studied

Mistletoe extract by injection under the skin (products not named in the abstracts).

Who was studied

Adults with locally advanced or metastatic pancreatic cancer.

Limits

Different primary outcomes. The 2013 trial's funding was not stated in the abstract. MISTRAL is an investigator-initiated trial with no declared conflicts.

Why researchers looked

Pancreatic cancer has poor outcomes, so any add-on treatment draws interest.

Traditional use

Injected mistletoe extracts have been used as an add-on to cancer care in German-speaking countries for about 100 years (Oei 2019 review) and are widely prescribed in parts of Europe (NCI).

Proposed mechanism Laboratory research

In the lab, mistletoe lectins and viscotoxins kill cells and stimulate immune cells. Lab results in dishes and animals do not show that the injected extract helps people with cancer.

A proposed mechanism does not show that the effect happens in people.

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Quality of life in cancer (all types)

Low certainty

Pooled results show a medium-sized improvement in how patients rate their quality of life, but most studies had a high risk of bias and cannot be blinded.

4 studiesVarious injected extracts.

Studies, doses and limits

What the trials found

Loef 2020 (26 publications, 30 data sets): pooled global quality of life d = 0.61 (95% CI 0.41 to 0.81); the effect was stronger in studies with lower risk of bias and in randomised, blinded studies, and half of the subdomains (for example pain, nausea) improved. Most studies had a high risk of bias or some concerns. Cochrane (2008) found 14 of 16 quality-of-life trials showed some benefit but only 2, in breast cancer during chemotherapy, were higher quality. NCI notes two randomised lung cancer trials with no quality-of-life difference against chemotherapy. Lab-measured and self-rated outcomes can be influenced by knowing which treatment you receive.

Results

A possible medium-sized quality-of-life benefit, uncertain because of study design.

Effect sizes as reported

SMD d = 0.61 (95% CI 0.41-0.81) (Loef 2020).

Why this rating

Pooled effect is sizeable, but most studies are open-label with high risk of bias, and a large placebo-controlled trial in pancreatic cancer (MISTRAL) found no benefit. Cochrane (2008) also called the quality-of-life evidence needing replication.

Form and dose studied

Various injected extracts.

Who was studied

Cancer patients of many types, often during chemotherapy.

Limits

Quality-of-life scores are self-rated and the effect may be partly expectation; blinding is hard with injections that cause a local skin reaction.

Why researchers looked

The main reason many patients use mistletoe is to feel better during cancer treatment.

Traditional use

Injected mistletoe extracts have been used as an add-on to cancer care in German-speaking countries for about 100 years (Oei 2019 review) and are widely prescribed in parts of Europe (NCI).

Proposed mechanism Laboratory research

In the lab, mistletoe lectins and viscotoxins kill cells and stimulate immune cells. Lab results in dishes and animals do not show that the injected extract helps people with cancer.

A proposed mechanism does not show that the effect happens in people.

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Quality of life in breast cancer

Moderate certainty

The best-supported setting: nine randomised trials point to better quality of life during breast cancer treatment, rated moderate certainty by the reviewers.

2 studiesMistletoe extracts added to conventional treatment, injected.

Studies, doses and limits

What the trials found

Loef 2023 (9 randomised trials, 833 people; 7 non-randomised studies, 2831 people): randomised trials pooled SMD 0.61 (95% CI 0.47 to 0.75), non-randomised SMD 0.46 (0.10 to 0.82). Risk of bias was low to high in the randomised trials and serious in all non-randomised studies. The reviewers' GRADE rating: moderate certainty for randomised trials, very low for non-randomised. Cochrane 2008 reached a similar cautious view: some evidence of quality-of-life benefit in breast cancer on chemotherapy, needing replication.

Results

Possible quality-of-life benefit during breast cancer treatment.

Effect sizes as reported

SMD 0.61 (95% CI 0.47-0.75) randomised; SMD 0.46 (0.10-0.82) non-randomised.

Why this rating

The reviewers' own GRADE was moderate for the randomised trials (Loef 2023). We keep the same rating, and flag that blinding is difficult and that one author's institute received funding from a society linked to a mistletoe maker (declared in Pelzer 2022).

Form and dose studied

Mistletoe extracts added to conventional treatment, injected.

Who was studied

Women with breast cancer, mostly during chemotherapy.

Limits

Quality of life is self-rated; blinding is difficult; the review authors call for more trials, especially in neoadjuvant chemotherapy and survivors.

Why researchers looked

Cochrane picked breast cancer on chemotherapy as the setting where quality of life might improve.

Traditional use

Injected mistletoe extracts have been used as an add-on to cancer care in German-speaking countries for about 100 years (Oei 2019 review) and are widely prescribed in parts of Europe (NCI).

Proposed mechanism Laboratory research

In the lab, mistletoe lectins and viscotoxins kill cells and stimulate immune cells. Lab results in dishes and animals do not show that the injected extract helps people with cancer.

A proposed mechanism does not show that the effect happens in people.

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Cancer-related tiredness (fatigue)

Low certainty

Randomised trials pooled to a moderate reduction in fatigue, but most studies were high risk of bias and the review has links to a mistletoe maker.

1 studiesMistletoe extracts, injected.

Studies, doses and limits

What the trials found

Pelzer 2022 pooled 12 randomised trials (1494 people): SMD -0.48 (95% CI -0.82 to -0.14); 7 retrospective non-randomised studies (2668 people): odds ratio 0.36 (0.20 to 0.66). Heterogeneity was high in both and most studies had a high risk of bias. The authors compared the effect size to that of physical activity and asked for more placebo-controlled trials. Industry link: several authors are connected to Iscador AG (see study record).

Results

A possible moderate reduction in fatigue; not confirmed by placebo-controlled trials.

Effect sizes as reported

SMD -0.48 (95% CI -0.82 to -0.14) randomised; OR 0.36 (0.20-0.66) non-randomised.

Why this rating

High heterogeneity, most studies at high risk of bias, and some authors linked to a mistletoe manufacturer.

Form and dose studied

Mistletoe extracts, injected.

Who was studied

Cancer patients, many types.

Limits

Self-rated outcome, mostly open-label studies.

Why researchers looked

Fatigue is one of the commonest and most distressing symptoms in cancer.

Traditional use

Injected mistletoe extracts have been used as an add-on to cancer care in German-speaking countries for about 100 years (Oei 2019 review) and are widely prescribed in parts of Europe (NCI).

Proposed mechanism Laboratory research

In the lab, mistletoe lectins and viscotoxins kill cells and stimulate immune cells. Lab results in dishes and animals do not show that the injected extract helps people with cancer.

A proposed mechanism does not show that the effect happens in people.

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Quality of life after gastric cancer surgery (a pilot trial)

Very low certainty

One small randomised pilot of 32 people suggested better quality of life and less diarrhoea; too small to rely on.

1 studiesabnobaVISCUM Quercus, injected.

Studies, doses and limits

What the trials found

Kim 2012 (32 people, abnobaVISCUM Quercus by injection for up to 24 weeks, versus no additional therapy): global health status improved (p < 0.01), leukocyte and eosinophil counts rose, diarrhoea was reported less often (7% vs 50%, p = 0.014). No significant effect on TNF-alpha, IL-2, natural killer or B cells, or liver tests.

Results

Suggestive but small and open-label.

Effect sizes as reported

Global health p < 0.01; diarrhoea 7% vs 50%.

Why this rating

Single pilot, 32 people, no placebo.

Form and dose studied

abnobaVISCUM Quercus, injected.

Who was studied

Operated stage Ib-II gastric cancer.

Limits

Pilot size; open comparison.

Why researchers looked

Tested in people waiting to start oral chemotherapy after stomach cancer surgery.

Traditional use

Injected mistletoe extracts have been used as an add-on to cancer care in German-speaking countries for about 100 years (Oei 2019 review) and are widely prescribed in parts of Europe (NCI).

Proposed mechanism Laboratory research

In the lab, mistletoe lectins and viscotoxins kill cells and stimulate immune cells. Lab results in dishes and animals do not show that the injected extract helps people with cancer.

A proposed mechanism does not show that the effect happens in people.

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Around cancer surgery (recurrence and death)

Low certainty

Seven randomised trials around cancer surgery found no difference in death or return of cancer.

1 studiesMistletoe extracts around surgery, injected.

Studies, doses and limits

What the trials found

Cogo 2023 (7 randomised trials, 663 people, plus 3 non-randomised studies): no difference between mistletoe and no added therapy for mortality (RR 1.00, 95% CI 0.79 to 1.27) or recurrence (RR 1.03, 0.79 to 1.33). Two trials reported higher natural killer cells in colorectal cancer, and one reported better quality of life. Two trials reported stopping mistletoe because of adverse events or grade 3/4 toxicity, although the review saw no overall safety signal. Risk of bias was substantial.

Results

No effect on death or recurrence; small, unconfirmed immune-cell changes.

Effect sizes as reported

Mortality RR 1.00 (0.79-1.27); recurrence RR 1.03 (0.79-1.33).

Why this rating

Reviewers describe the data as preliminary, with few studies, different outcomes and substantial risk of bias. The mortality and recurrence results are null.

Form and dose studied

Mistletoe extracts around surgery, injected.

Who was studied

Adults having cancer surgery (colorectal and others).

Limits

Small trials; only two reported immune cells; different outcomes.

Why researchers looked

Some trials gave mistletoe around the time of surgery to see if it protects against recurrence.

Traditional use

Injected mistletoe extracts have been used as an add-on to cancer care in German-speaking countries for about 100 years (Oei 2019 review) and are widely prescribed in parts of Europe (NCI).

Proposed mechanism Laboratory research

In the lab, mistletoe lectins and viscotoxins kill cells and stimulate immune cells. Lab results in dishes and animals do not show that the injected extract helps people with cancer.

A proposed mechanism does not show that the effect happens in people.

Blood immune markers (lab-measured, not a health outcome)

Not enough evidence

In healthy volunteers and some patients, injections change some immune markers. This does not show a health benefit.

4 studiesInjected extracts (Iscador, abnobaVISCUM, others).

Studies, doses and limits

What the trials found

Huber 2006 (47 healthy volunteers, 12 weeks of Iscador Quercus, Iscador Pinus or saline): blood cells exposed to either extract in the lab grew and released cytokines; in treated volunteers TNF-alpha release rose after the lectin-rich extract (week 25) and IL-5 and IL-13 fell after the viscotoxin-rich extract; the placebo group also showed immune changes. Kim 2012 (gastric cancer, 32 people): leukocyte and eosinophil counts rose, but TNF-alpha, IL-2, natural killer and B-cell levels did not change significantly. MISTRAL 2026 (pancreatic cancer, 290 people): no effect on lymphocyte subsets or C-reactive protein; eosinophils rose with no link to any clinical effect.

Results

Some immune markers move; none has been shown to translate into a health benefit.

Effect sizes as reported

No pooled numbers.

Why this rating

Marker changes are inconsistent between studies and are not clinical outcomes.

Form and dose studied

Injected extracts (Iscador, abnobaVISCUM, others).

Who was studied

Healthy volunteers and cancer patients.

Limits

Marker changes are not benefits; immune activation could matter in people with autoimmune disease or on immune drugs (see safety).

Why researchers looked

Mistletoe is called an immune modulator. Researchers measure blood cells and cytokines to test this.

Traditional use

Injected mistletoe extracts have been used as an add-on to cancer care in German-speaking countries for about 100 years (Oei 2019 review) and are widely prescribed in parts of Europe (NCI).

Proposed mechanism Laboratory research

Mistletoe lectins and viscotoxins stimulate immune cells in the lab; reviews describe immune-modulating effects (Oei 2019), but the clinical meaning is unknown.

A proposed mechanism does not show that the effect happens in people.

^{8 10 27 18}

Traditional non-cancer uses (epilepsy, asthma, high blood pressure, arthritis)

Not enough evidence

Mistletoe was used for centuries for many conditions, but none of the sources read tested it for these uses in people.

3 studiesNot applicable. Do not use mistletoe tea or home preparations for the…

Studies, doses and limits

What the trials found

No human trial of mistletoe for epilepsy, asthma, high blood pressure or arthritis was found in the sources read. NCI describes these only as traditional uses.

Results

Not tested in the sources read.

Effect sizes as reported

None.

Why this rating

No human evidence found in the search; traditional use alone does not show benefit or safety.

Form and dose studied

Not applicable. Do not use mistletoe tea or home preparations for these.

Who was studied

None tested.

Limits

Search was targeted at cancer reviews and safety; a few small non-cancer studies may exist and were not read.

Why researchers looked

These are the older folk uses listed by the NCI and a chemistry review.

Traditional use

NCI lists traditional uses including epilepsy, asthma, high blood pressure, headaches, menopausal symptoms, infertility, dermatitis, arthritis and rheumatism. Home brewing of mistletoe tea is dangerous (see safety).

Proposed mechanism Pharmacological theory

A chemistry review says phenolic compounds in the plant 'decrease blood pressure' in lab work; no human trial was read.

A proposed mechanism does not show that the effect happens in people.

Mistletoe tea has been linked to serious poisonings and deaths (Poison Control).

^{15 17 22}

Connections to the rest of health

How Mistletoe connects to the rest of our health knowledge graph. Every link says what kind of connection it is. A safety link (for example to the liver) is a warning, not a benefit. A study that merely mentions a topic never creates a benefit link.

Explore every connection: goals, body systems, organs, symptoms, genes

Kind of connection Connected to Search

A. Wellness goals

Connected to	Kind of connection	Evidence status	Context	Studies
Immune Support	Potential benefit	Low certainty	Overall survival in cancer (all reviews): Most reviews that looked at living longer found no reliable benefit once study quality was taken into account. Low-quality studies look better than high-quality ones. Survival with non-fermented mistletoe extract (one meta-analysis): One meta-analysis of a subgroup of products found a longer survival, but it did not hold when active treatments were the comparison, and the studies were at moderate to high risk of bias.	^{7 3 6 24 16 12 26 27 15 11 10 2}
Immune Support	Demonstrated clinical effect	Moderate certainty	Quality of life in breast cancer: The best-supported setting: nine randomised trials point to better quality of life during breast cancer treatment, rated moderate certainty by the reviewers.	^{13 7}
Reduce Fatigue	Potential benefit	Low certainty	Cancer-related tiredness (fatigue): Randomised trials pooled to a moderate reduction in fatigue, but most studies were high risk of bias and the review has links to a mistletoe maker.	²¹
Immune Support	Preliminary mechanism	Not enough evidence	Blood immune markers (lab-measured, not a health outcome): In healthy volunteers and some patients, injections change some immune markers. This does not show a health benefit.	^{8 10 27 18}
Blood Pressure Support	Traditional use	Not enough evidence	Traditional non-cancer uses (epilepsy, asthma, high blood pressure, arthritis): Mistletoe was used for centuries for many conditions, but none of the sources read tested it for these uses in people.	^{15 17 22}
Joint Support	Traditional use	Not enough evidence	Traditional non-cancer uses (epilepsy, asthma, high blood pressure, arthritis): Mistletoe was used for centuries for many conditions, but none of the sources read tested it for these uses in people.	^{15 17 22}

B. Body systems

Connected to	Kind of connection	Evidence status	Context	Studies
Immune system	Adverse effect or risk	Very low certainty	Allergic reactions including anaphylaxis (case reports) and flu-like symptoms; immune activation could matter with autoimmune disease or immune drugs. Anaphylaxis (case reports) and flu-like symptoms; immune activation could matter with autoimmune disease or immune drugs. Preparation or compound: Injected extracts	^{9 1 19}
Immune System	Biological association	Low certainty	Studied for: Overall survival in cancer (all reviews) Studied for: Survival with non-fermented mistletoe extract (one meta-analysis)	^{7 3 6 24 16 12 26 27 15 11 13 21 10 2 8 18 17 22}

C. Body parts and organs

Connected to	Kind of connection	Evidence status	Context	Studies
Liver	Adverse effect or risk	Very low certainty	Reversible liver injury at high doses in some cases (NCI). Preparation or compound: Recombinant mistletoe lectin (not an extract)	¹⁶
Skin	Adverse effect or risk	Low certainty	Injection-site soreness and inflammation are the commonest effects. Preparation or compound: Injected extracts	^{16 7}

I. Biomarkers

Connected to	Kind of connection	Evidence status	Context	Studies
Overall survival (time until death from any cause)	Biological association	Low certainty	Measured in trials: mixed. A lab change is not the same as a health benefit.	^{6 26 3 7}
Global quality of life score	Biological association	Low certainty	Measured in trials: mixed. A lab change is not the same as a health benefit.	^{11 27 13 10}
Cancer-related fatigue score	Biological association	Low certainty	Measured in trials: lowered. A lab change is not the same as a health benefit.	²¹
Eosinophils and white blood cells	Biological association	Low certainty	Measured in trials: raised. A lab change is not the same as a health benefit.	^{10 27}
Cytokines (immune signalling proteins such as TNF-alpha, IL-5, IL-13)	Biological association	Not enough evidence	Measured in trials: mixed. A lab change is not the same as a health benefit.	^{8 10}

J. Genes, receptors and enzymes

Connected to	Kind of connection	Evidence status	Context	Studies
TNF (tumour necrosis factor alpha)	Preliminary mechanism	Human	Release rose in blood cells of healthy volunteers after a lectin-rich extract.	⁸
IL5 / IL13 (type 2 cytokines)	Preliminary mechanism	Human	Fell after a viscotoxin-rich extract in healthy volunteers.	⁸

L. Active compounds

Connected to	Kind of connection	Evidence status	Context	Studies
Mistletoe lectins (viscumin, ML I-III)	Biological association	In vitro	Bind to cells and trigger chemical changes in immune cells and cell death in the lab (NCI). In 47 healthy volunteers, the lectin-rich extract raised TNF-alpha release by blood cells. Preparation or compound: Varies by host tree; Iscador Quercus is lectin-rich, Iscador Pinus is lectin-poor	^{16 8}
Viscotoxins (for example viscotoxin A3)	Biological association	In vitro	Form ion channels in membranes and show cell-killing and antimicrobial activity in the lab (NMR study). Preparation or compound: Not stated in the sources read	^{20 16}
Polysaccharides	Biological association	In vitro	Named by NCI as one of three components that may account for mistletoe's immune effects. Details not read. Preparation or compound: Not stated	¹⁶
Flavonoids, phenolic acids, triterpenes	Biological association	In vitro	Antioxidant and anti-inflammatory activity in the lab; a review says these may lower blood pressure. Preparation or compound: Not stated	¹⁷
Quercetin (example flavonoid)	Biological association	In vitro	PubChem record only. Whether quercetin is a major mistletoe constituent was not confirmed from a source read; the review names flavonoids as a class. Preparation or compound: Not stated	^{14 17}

Each connection is stored with the ingredient, the connected record, the kind of connection, the evidence status, the supporting studies, the preparation or compound involved, and a review date (last reviewed October 25, 2026).

Evidence at a glance: what changed in 5 lab markers

Tap a number to show only those markers. Counts are markers, not people.

Organ function1 Other13

The evidence

The research centre for Mistletoe. Every record here was checked against PubMed or the publisher's page; we never list a study we have not verified.

Evidence by outcome

Overall survival in cancer (all reviews) 5 studies Low certainty Survival with non-fermented mistletoe extract (one meta-analysis) 2 studies Very low certainty Advanced pancreatic cancer (two randomised trials that disagree) 3 studies · 510 people in trials Low certainty Quality of life in cancer (all types) 4 studies · 290 people in trials Low certainty Quality of life in breast cancer 2 studies Moderate certainty Cancer-related tiredness (fatigue) 1 studies Low certainty Quality of life after gastric cancer surgery (a pilot trial) 1 studies · 32 people in trials Very low certainty Around cancer surgery (recurrence and death) 1 studies Low certainty Blood immune markers (lab-measured, not a health outcome) 4 studies · 369 people in trials Not enough evidence Traditional non-cancer uses (epilepsy, asthma, high blood pressure, arthritis) 3 studies Not enough evidence

Bars show how many studies we found for each outcome, not how well it works. People are added up across trials only (reviews are not added, to avoid double counting).

How we rate evidence

High certainty

Several well-run trials or reviews agree; further research is unlikely to change the picture much.

Moderate certainty

Good trials point the same way, but some doubt remains.

Low certainty

Small, short or inconsistent trials. The finding could change with better research.

Very low certainty

Very little or very weak human data. Treat as a possibility only.

Mixed findings

Trials or reviews disagree with each other.

Not enough evidence

Not enough human research to say either way.

Evidence against

Good research found no benefit, or found harm.

We take the reviewers' own risk-of-bias and GRADE statements where they exist, and otherwise judge from study size, design, consistency, directness and whether a product matches what is sold. Many publications do not make evidence high. Method note: We started from our earlier evidence summary for mistletoe, read the National Cancer Institute PDQ pages and the Poison Control article, and read PubMed abstracts for the studies cited. Plant names were checked in GBIF and NCBI Taxonomy. Not read: LiverTox, LactMed, NCCIH, EMA documents, manufacturer prescribing information. Most studies were read as abstracts only; one case report has a title only. Certainty ratings are the compiler's reading, using the reviewers' own GRADE where given.

Study library: every study we checked 27

Design Research type Plant part Year from Search

Study	Design	People	Product, dose, length	Result
Casetti 2021 Grade II-anaphylaxis after subcutaneous injection of mistletoe extract Contact Dermatitis · PMID 33963569 · DOI	Case report	1 One patient	Mistletoe extract, subcutaneous injection unspecified	Title reports grade II anaphylaxis after a subcutaneous mistletoe injection. No abstract was available, so no further detail was read. Methods, limits and funding Outcomes: Safety Limitations: Only the title and citation were read. Funding and conflicts: Not available. Read: title-only
Cogo 2023 Mistletoe Extracts during the Oncological Perioperative Period: A Systematic Review and Meta-Analysis of Human Randomized Controlled Trials Curr Oncol · PMID 37754510 · DOI	Meta-analysis	663 7 randomised trials (663 people) and 3 non-randomised studies around cancer surgery	Mistletoe extracts unspecified · vs No added therapy (5 trials); head-to-head against etoposide or BCG (2 trials)	No difference in mortality (RR 1.00) or recurrence (RR 1.03) versus no added therapy. Two trials reported higher natural killer cells in colorectal cancer; one reported better quality of life. Two trials reported stopping mistletoe because of adverse events or grade 3/4 toxicity, yet no safety signal was seen overall. Substantial risk of bias. RR 1.00 mortality; RR 1.03 recurrence (0.79-1.27 (mortality); 0.79-1.33 (recurrence)) Methods, limits and funding Outcomes: Mortality, recurrence, immune cells, quality of life, safety Limitations: Few studies, different outcomes, methodological limits. Authors call the data 'preliminary'. Funding and conflicts: No conflicts declared. Registered PROSPERO CRD42018086168. Registration: CRD42018086168 Read: abstract
Freuding 2019 Mistletoe in oncological treatment: a systematic review. Part 1: survival and safety J Cancer Res Clin Oncol · PMID 30673873 · DOI	Systematic review	2639 28 publications in cancer patients (14 studies with overall survival, n = 1054)	Viscum album (European mistletoe) extract, injected (various products), nearly always added to usual treatment unspecified · vs Usual treatment alone	Most studies showed no effect of mistletoe on survival. High-quality studies did not show any benefit. Authors: the literature gives no reason to prescribe mistletoe to cancer patients for the purpose of survival. Methods, limits and funding Outcomes: Overall survival; progression-free or disease-free survival; tumour response; safety Limitations: Search to October 2017; narrative review without pooled estimate in the abstract. Funding and conflicts: No conflicts declared. Read: abstract
GBIF Secretariat 2026 GBIF backbone match: Viscum album L. GBIF API · Source	Database record	not applicable	Viscum album L. not applicable	Accepted species, key 2889828, family Viscaceae, order Santalales (exact match, confidence 97). Retrieved 2026-10-25. Methods, limits and funding Limitations: Backbone taxonomy; some systems place the family in Santalaceae or Loranthaceae. Read: full-text
GBIF Secretariat 2026 GBIF backbone match: Phoradendron leucarpum GBIF API · Source	Database record	not applicable	Phoradendron leucarpum (Raf.) Reveal & M.C.Johnst. not applicable	Accepted name key 2889887, family Viscaceae. This is the species commonly called American mistletoe; the older names P. serotinum and P. flavescens appear in the papers read. Retrieved 2026-10-25. Methods, limits and funding Limitations: Name-synonym link between P. flavescens and P. leucarpum was not checked in GBIF. Read: full-text
Hofinger 2024 Systematic assessment of the influence of quality of studies on mistletoe in cancer care on the results of a meta-analysis on overall survival J Cancer Res Clin Oncol · PMID 38679615 · DOI	Meta-analysis	28 publications covering 28,298 cancer patients (randomised and non-randomised)	Viscum album (European mistletoe) extract, injected (various products) unspecified · vs Usual treatment alone	All studies pooled: overall HR 0.61 in favour of mistletoe. Among randomised studies of higher quality (lower risk of bias), the result was not significant (HR 0.78). Pooled all studies HR 0.61; higher-quality randomised studies HR 0.78 (0.53-0.70 (all studies); 0.30-2.00 (higher-quality randomised studies)) Methods, limits and funding Outcomes: Overall survival, with risk-of-bias assessment (ROB 2.0, ROBINS-I) Limitations: Search April-August 2022. Wide interval for the high-quality subgroup means a large benefit or a harm cannot be excluded. Authors conclude low-quality studies can cause misinterpretation. Funding and conflicts: No conflicts declared. Read: abstract
Horneber 2008 Mistletoe therapy in oncology Cochrane Database Syst Rev · PMID 18425885 · DOI	Systematic review	3484 Adults with any cancer; 21 randomised trials (13 on survival, 16 on quality of life or related outcomes, 12 on side effects)	Mistletoe extracts from 5 manufacturers plus one product not on the market unspecified (injected extracts) · vs Usually no extra treatment or standard care	Of 13 survival trials, 6 showed some benefit but none was of high quality; two trials (melanoma, head and neck) suggested no survival benefit. Of 16 quality-of-life trials, 14 showed some benefit but only 2 (breast cancer on chemotherapy) were of higher quality. Side effects were usually few and dose-dependent. Reviewers' conclusion: evidence of an effect on survival or on coping with cancer treatment is weak; possible quality-of-life benefit during breast cancer chemotherapy needs replication. No pooled estimate (results presented in words). Methods, limits and funding Outcomes: Survival, tumour response, quality of life, side effects of cancer treatment, safety of the extract Limitations: Search ended August 2007, so newer trials are not included. Poor reporting of the original trials. Two authors received research funding and honoraria from mistletoe makers (declared; the review itself was independent). Funding and conflicts: Two of five authors declared research funding and speaking fees from mistletoe manufacturers. Read: abstract
Huber 2006 In vitro immunoreactivity towards lectin-rich or viscotoxin-rich mistletoe (Viscum album L.) extracts Iscador applied to healthy individuals Arzneimittelforschung · PMID 16927525 · DOI	Controlled trial	47 47 healthy volunteers injected for 12 weeks; blood cells tested later in the lab	Iscador Quercus (lectin-rich) or Iscador Pinus (lectin-poor, viscotoxin-rich), injected unspecified 12 weeks of injections; follow-up to week 25 · vs Saline placebo	Blood cells from untreated people grew and released cytokines when exposed to either extract. In treated volunteers, TNF-alpha release rose with the lectin-rich extract at week 25, and type 2 cytokines IL-5 and IL-13 fell with the viscotoxin-rich extract. The placebo group also showed immune changes over time. Immune markers changed; clinical meaning not shown (not given) Methods, limits and funding Outcomes: Blood-cell growth and cytokine release Limitations: Healthy volunteers, lab measures of immune cells, not health outcomes. Placebo changes make interpretation hard. Funding and conflicts: Not stated in the abstract. Read: abstract
Kaemmerer 2024 [Anaphylactic shock after mistletoe therapy] Inn Med (Heidelb) · PMID 39019992 · DOI	Case report	1 One patient with a neuroendocrine neoplasm and carcinoid syndrome (German-language report)	Mistletoe therapy (product not named in the abstract) unspecified	Life-threatening anaphylactic shock after mistletoe therapy. The authors say such reactions are often denied by complementary-medicine physicians, and that flushing, diarrhoea and wheeze from carcinoid syndrome can mask the diagnosis. Methods, limits and funding Outcomes: Safety Limitations: Single case report; German-language abstract read via the English publisher text. Funding and conflicts: None stated. Read: abstract
Kim 2012 Quality of life, immunomodulation and safety of adjuvant mistletoe treatment in patients with gastric carcinoma - a randomized, controlled pilot study BMC Complement Altern Med · PMID 23033982 · DOI	Controlled trial	32 Operated stage Ib-II gastric cancer patients waiting for oral chemotherapy (doxifluridine), Seoul	abnobaVISCUM Quercus (standardised mistletoe extract), subcutaneous injection unspecified Increasing doses three times a week From postoperative day 7 to week 24 · vs No additional therapy	Global health status improved versus control (p < 0.01). Leukocyte and eosinophil counts rose (p <= 0.01). Diarrhoea was reported less often (7% vs 50%, p = 0.014). No significant effect on TNF-alpha, IL-2, natural killer or B-cell levels, or on liver tests. Global health status p < 0.01 (not given in the abstract) Methods, limits and funding Outcomes: Quality of life (EORTC QLQ-C30, STO22), blood counts, liver tests, cytokines, lymphocyte subsets Limitations: Pilot study of 32 people; open comparison with no placebo, so people knew their group. Funding and conflicts: Funding and conflicts not stated in the abstract (not checked further). Registration: NCT01401075 Read: abstract
Loef 2020 Quality of life in cancer patients treated with mistletoe: a systematic review and meta-analysis BMC Complement Med Ther · PMID 32690087 · DOI	Meta-analysis	26 publications with 30 data sets in cancer patients; prospective controlled trials	Mistletoe extracts (various) unspecified · vs Control (mostly usual care)	Pooled global quality of life improved after mistletoe versus control. Half of the subdomains (for example pain, nausea) improved. Most studies had a high risk of bias or raised some concern. Standardised mean difference d = 0.61 (medium-sized) (0.41-0.81) Methods, limits and funding Outcomes: Global quality of life and subdomains Limitations: Heterogeneous studies; most with high risk of bias; blinding is difficult. The authors judged the bias unlikely to change the outcome, which is their view and not a tested fact. Funding and conflicts: No conflicts declared. Registered PROSPERO CRD42019137704. Registration: CRD42019137704 Read: abstract
Loef 2022 Survival of Cancer Patients Treated with Non-Fermented Mistletoe Extract: A Systematic Review and Meta-Analysis Integr Cancer Ther · PMID 36324298 · DOI	Meta-analysis	11 randomised trials and 8 non-randomised studies in cancer patients	Non-fermented mistletoe extracts unspecified · vs Usual care or active comparators	Randomised trials pooled: HR 0.81 (95% CI 0.69-0.95). Adding active comparators made the estimates non-significant. Studies were heterogeneous with moderate (randomised) to high (non-randomised) risk of bias. HR 0.81 for overall survival (randomised trials) (0.69-0.95) Methods, limits and funding Outcomes: Overall survival Limitations: Authors call for high-quality randomised trials. Result depends on which comparators are included. Funding and conflicts: Authors declared no conflicts. Registered PROSPERO CRD42021233177. Registration: CRD42021233177 Read: abstract
Loef 2023 Quality of Life in Breast Cancer Patients Treated With Mistletoe Extracts: A Systematic Review and Meta-Analysis Integr Cancer Ther · PMID 37888846 · DOI	Meta-analysis	3664 Breast cancer patients: 9 randomised trials (833 people) and 7 non-randomised studies (2831 people)	Mistletoe extracts added to conventional treatment unspecified · vs Conventional treatment alone	Randomised trials: pooled SMD 0.61. Non-randomised: SMD 0.46. Risk of bias low to high in randomised trials, serious in all non-randomised studies. Reviewers' GRADE: moderate certainty for randomised trials, very low for non-randomised. SMD 0.61 (randomised); SMD 0.46 (non-randomised) (0.47-0.75 (randomised); 0.10-0.82 (non-randomised)) Methods, limits and funding Outcomes: Quality of life (before-after change); GRADE certainty Limitations: Blinding is difficult. Further trials needed, especially in neoadjuvant chemotherapy and survivors. Funding and conflicts: No conflicts declared. Read: abstract
NCBI PubChem 2026 PubChem: Quercetin PubChem API · Source	Database record	not applicable	Quercetin not applicable	CID 5280343, formula C15H10O7. Retrieved 2026-10-25. Methods, limits and funding Limitations: Confirms the compound record only; that quercetin is present in Viscum album was not confirmed from a source read. Read: full-text
National Cancer Institute 2023 Mistletoe Extracts (PDQ), Patient Version cancer.gov PDQ · Source	Authoritative guidance	Cancer patients	Mistletoe extracts whole plant extracts	Extracts usually given by injection under the skin; less often by mouth, into a vein, the pleural cavity or a tumour. Traditional uses listed: epilepsy, asthma, hypertension, headaches, menopausal symptoms, infertility, dermatitis, arthritis, rheumatism. Studies with large numbers reported mixed results; some had small numbers, poor design or missing detail. Two randomised lung cancer trials showed no quality-of-life difference versus chemotherapy; a melanoma trial showed no survival gain. FDA has not approved mistletoe extract for cancer or any condition. Methods, limits and funding Limitations: Patient summary; summary updated 2023-06-21. Read: full-text
National Cancer Institute 2024 Mistletoe Extracts (PDQ), Health Professional Version cancer.gov PDQ · Source	Authoritative guidance	Cancer patients	European mistletoe (Viscum album) extracts whole plant extracts	Mistletoe is one of the most widely studied complementary therapies in cancer. Injectable extracts are prescription drugs in Europe, not available commercially in the US and not approved as a cancer treatment. Plants and berries are considered poisonous. Reports of improved survival or quality of life have been common, but many studies had major weaknesses. Common side effects: injection-site soreness and inflammation, headache, fever, chills; a few cases of severe allergic reaction including anaphylaxis; high doses of recombinant (lab-made) lectin caused reversible liver injury in some cases. Content varies by host tree, harvest time, preparation and maker. Methods, limits and funding Limitations: Page was read through its main text; the reference list was not opened. Last updated 2024 per our earlier summary. Read: full-text
Nazaruk 2016 Phytochemical profile and therapeutic potential of Viscum album L. Nat Prod Res · PMID 25813519 · DOI	Narrative review None stated.	Review of chemistry and pharmacology	Viscum album whole plant extracts	Chemistry of mistletoe Lectins and viscotoxins are the best-described active compounds; others include phenolic acids, phenylpropanoids, flavonoids, triterpenes, phytosterols and oligo- and polysaccharides. Composition varies with harvest time, host tree and manufacture. Traditional use in hypertension and arthritis is mentioned. Methods, limits and funding Funding and conflicts: Narrative review of mostly lab work. Registration: abstract Read: mixed
Oei 2019 Mistletoe and Immunomodulation: Insights and Implications for Anticancer Therapies Evid Based Complement Alternat Med · PMID 31118962 · DOI	Narrative review mixed	Review of lab and clinical work	Viscum album preparations and compounds unspecified	Review describes immune-modulating effects of mistletoe and says it has been used for about 100 years as an add-on in German-speaking countries. The abstract gives no numbers. Methods, limits and funding Outcomes: Immune effects of mistletoe Limitations: Narrative review; the abstract states benefits more strongly than the trial reviews support. Authors are linked to Network Oncology, partly funded by mistletoe makers. Funding and conflicts: Authors work with a registry funded in part by mistletoe makers (see Oei 2019). Read: abstract
Oei 2019 Use and Safety of Viscum album L Applications in Cancer Patients With Preexisting Autoimmune Diseases: Findings From the Network Oncology Study Integr Cancer Ther · PMID 30808274 · DOI	Cohort study	106 Cancer patients with existing autoimmune disease (Hashimoto's 27%, psoriasis 19%, ulcerative colitis 15%), Germany registry	Viscum album extracts added to standard care unspecified 30 people on long-term therapy · vs Observed periods without mistletoe	17 people (16%) had mistletoe-related adverse events; no long-term side effects or stopping of mistletoe were recorded; no flares of the autoimmune disease in the 30 people on long-term therapy. Overall adverse event rates were halved during mistletoe periods. 16% had mistletoe-related adverse events (not given) Methods, limits and funding Outcomes: Adverse events; flares of autoimmune disease Limitations: Observational registry with no randomised control; authors advise caution in interpreting. Funding and conflicts: Registry partly funded by mistletoe makers Iscador AG, Abnoba GmbH and Helixor Heilmittel GmbH; authors report grants from the makers. Read: abstract
Paramonov 2021 Spatial structure and oligomerization of viscotoxin A3 in detergent micelles: Implication for mechanisms of ion channel formation and membrane lysis Biochem Biophys Res Commun · PMID 34781057 · DOI	In vitro study in-vitro	Laboratory structure study (NMR)	Viscotoxin A3 (mistletoe peptide) viscotoxin peptide	Viscotoxin A3 is a small (about 5 kDa) cationic peptide that forms ion channels in membranes with negatively charged fats and shows antimicrobial and cell-killing activity in the lab. NMR showed a helical hairpin plus a short beta-sheet. Methods, limits and funding Outcomes: Structure and membrane behaviour Limitations: Test-tube study of a purified peptide; says nothing about effects in people. Funding and conflicts: Funded by the Russian Science Foundation. Read: abstract
Pelzer 2022 Cancer-related fatigue in patients treated with mistletoe extracts: a systematic review and meta-analysis Support Care Cancer · PMID 35239008 · DOI	Meta-analysis	4162 12 randomised trials (1494 people) and 7 retrospective non-randomised studies (2668 people) in cancer patients	Mistletoe extracts unspecified · vs Control groups	Randomised trials: lower fatigue with mistletoe, SMD -0.48. Non-randomised studies: odds ratio 0.36. High heterogeneity; most studies had a high risk of bias. SMD -0.48 (randomised); OR 0.36 (non-randomised) (-0.82 to -0.14 (randomised); 0.20-0.66 (non-randomised)) Methods, limits and funding Outcomes: Cancer-related fatigue severity or prevalence Limitations: Authors call for more placebo-controlled trials. Funding and conflicts: Industry link: two authors are employed by a society that is a minority shareholder of mistletoe maker Iscador AG; one is part-time employed by Iscador AG; another author's institute received funding from the same society. Registration: CRD42020191967 Read: abstract
Poison Control (US national poison centers) Is mistletoe poisonous? poison.org · Source	Authoritative guidance	General public	American mistletoe (Phoradendron) and European mistletoe (Viscum album) leaf and berry	American mistletoe is much less toxic than its reputation; swallowing small amounts usually causes mild stomach upset at most. For the European species (Viscum album), the literature includes serious poisonings and deaths, usually from excessive concentrated herbal use such as brewing mistletoe as tea. V. album is not native to or sold in the US. Keep berries and leaves away from children and pets; do not decorate food with mistletoe. Methods, limits and funding Limitations: Public education article, not a systematic review; publication date not read. Read: full-text
Spiller 1996 Retrospective study of mistletoe ingestion J Toxicol Clin Toxicol · PMID 8699554 · DOI	Case series	92 92 accidental exposures to AMERICAN mistletoe (Phoradendron flavescens), mostly young children, three US poison centres	American mistletoe berries and leaves (a different plant from European mistletoe) leaf and berry	14 people had symptoms (11 linked to the plant): stomach upset, drowsiness, and one seizure in a 13-month-old whose exposure was unwitnessed. Symptoms began within 6 hours. No heart or blood-pressure effects. Authors concluded symptoms are infrequent even after up to 20 berries or 5 leaves. Methods, limits and funding Outcomes: Symptoms after swallowing Limitations: Different species (Phoradendron), so it does not show that European mistletoe (Viscum album) is safe to eat. Poison Control reports poisonings and deaths with the European species. Funding and conflicts: None stated. Read: abstract
Staupe 2023 Systematic analysis of mistletoe prescriptions in clinical studies J Cancer Res Clin Oncol · PMID 36481925 · DOI	Systematic review	19441 102 publications and 19,441 people (cancer patients, healthy volunteers, children)	Mistletoe preparations of many makers and host trees unspecified	Huge variation in extract type and composition, host tree, route and schedule. No link was found between the preparation, host tree or schedule and the cancer type treated. The authors could not derive transparent rules for treatment. Methods, limits and funding Outcomes: How mistletoe was prescribed Limitations: Describes prescribing, not effectiveness. Funding and conflicts: No conflicts declared. Read: abstract
Thronicke 2017 Clinical safety of combined therapy of immune checkpoint inhibitors and Viscum album L. therapy in patients with advanced or metastatic cancer BMC Complement Altern Med · PMID 29237435 · DOI	Cohort study	16 Advanced or metastatic cancer treated with checkpoint inhibitors (nivolumab 75%, ipilimumab 19%, pembrolizumab 6%); 9 also had mistletoe	Viscum album extract added to checkpoint inhibitor unspecified · vs Checkpoint inhibitor alone (7 people)	Adverse events in 67% (with mistletoe) versus 71% (without), not significantly different; no grade 3 or higher events. Authors say the design cannot exclude immune interactions. AE rate 67% vs 71%, not significant (not given) Methods, limits and funding Outcomes: Adverse event rates Limitations: Tiny pilot (16 people), observational, retrospectively registered. Funding and conflicts: Author reports grants from mistletoe makers Helixor Heilmittel GmbH, Iscador AG and Abnoba GmbH. Read: abstract
Tröger 2013 Viscum album [L.] extract therapy in patients with locally advanced or metastatic pancreatic cancer: a randomised clinical trial on overall survival Eur J Cancer · PMID 23890767 · DOI	Controlled trial	220 Locally advanced or metastatic pancreatic cancer; first interim analysis, one centre	Viscum album extract by subcutaneous injection (product not named in the abstract) unspecified Dose-escalating, 0.01 mg up to 10 mg three times a week Not stated in the abstract · vs No anticancer therapy (best supportive care in both groups)	Median survival 4.8 months with the extract versus 2.7 months in the control group; the authors report a 'non-toxic' profile with no extract-related adverse events. Prognosis-adjusted HR 0.49, p < 0.0001 (not given in the abstract) Methods, limits and funding Outcomes: 12-month overall survival (interim) Limitations: Open-label (no placebo), single centre, interim analysis of 220 people, and the comparison group received no anticancer treatment. The much larger double-blind MISTRAL trial (2026) found no benefit for quality of life. Funding and conflicts: Funding not stated in the abstract (not checked further). Read: abstract
Wode 2026 Mistletoe extract in patients with advanced pancreatic cancer: Health-related quality of life in a double-blind, randomized, placebo-controlled trial (MISTRAL) Palliat Med · PMID 42059487 · DOI	Controlled trial	290 Advanced pancreatic cancer, performance status 0-2, 9 oncology centres in Sweden; standard treatment (palliative chemotherapy or best supportive care) in both groups	Mistletoe extract by subcutaneous injection (product not named in the abstract) unspecified Up to 9 months of assessment · vs Placebo injection	No statistically significant differences in quality of life or weight. Costs of supportive care were similar. Blood markers were unchanged except more eosinophils (a type of white blood cell) in the mistletoe group, with no link to any clinical effect. Authors: no clinical reason to recommend mistletoe extract in advanced pancreatic cancer. No significant difference (not given in the abstract) Methods, limits and funding Outcomes: Quality of life (EORTC QLQ-C30, QLQ-PAN26), body weight, costs, blood biomarkers Limitations: Pancreatic cancer only. Investigator-initiated, double-blind and placebo-controlled; one of the best-designed trials found. Funding and conflicts: No conflicts declared. Registered EudraCT 2014-004552-64, NCT02948309. Registration: NCT02948309 Read: abstract

What we do not know yet

What the evidence supports: nothing is rated above low except quality of life in breast cancer (moderate).
No large independent placebo-controlled trial supports a survival benefit.
No data on pregnancy, breastfeeding or children.
No frequency for severe allergic reactions.
Interactions with immune drugs are only studied in small observational studies.
LiverTox, LactMed, EMA and manufacturer prescribing information were not read.

How new research is added

New studies are found by a saved PubMed search and placed in a review queue. A person reads each one before it changes any rating or safety wording.

Lab markers

What changed in blood or saliva tests during trials. A changed number is not the same as feeling or being healthier, and we give no "normal ranges".

Organ function 1

▲

Eosinophils and white blood cells

Raised in trials

Eosinophils are a type of white blood cell involved in allergic reactions and some parasite defence. Leukocytes are all white blood cells.

Low certainty

Results and what it means

Why it was measured

Used as a sign that the injected extract is acting on the immune system.

Statistical vs. clinical meaning

Statistically significant in two trials, but the MISTRAL authors found no link to clinical effect.

Safety implication

Eosinophil rises may relate to allergic-type reactions; the studies read do not say.

Study	Result	People	Product
¹⁰	Leukocyte and eosinophil counts rose in the mistletoe group versus control (p <= 0.01).	32 operated gastric cancer patients	abnobaVISCUM Quercus injection, up to 24 weeks
²⁷	Eosinophils were statistically higher in the mistletoe arm, with no association to any clinical effect.	290 people with advanced pancreatic cancer	Mistletoe extract vs placebo injection

^{10 27}

Other 4

↕

Overall survival (time until death from any cause)

Mixed results in trials

How long people live after the start of treatment.

Low certainty

Results and what it means

Why it was measured

The outcome that matters most in cancer trials.

Statistical vs. clinical meaning

Statistical benefit in low-quality pools disappears in high-quality ones; clinically unproven.

Safety implication

Using mistletoe instead of proven treatment could cost lives; discuss with the cancer team.

Study	Result	People	Product
⁶	All studies pooled HR 0.61 (0.53-0.70); randomised studies at lower risk of bias HR 0.78 (0.30-2.00), not significant.	28 publications, 28,298 cancer patients	Mistletoe extracts, various
²⁶	Median survival 4.8 vs 2.7 months; adjusted HR 0.49.	220 people with advanced pancreatic cancer	Subcutaneous Viscum album extract vs no anticancer therapy

^{6 26 3 7}

↕

Global quality of life score

Mixed results in trials

A questionnaire score (such as EORTC QLQ-C30) in which people rate their own health, symptoms and daily function.

Low certainty

Results and what it means

Why it was measured

Tells how a patient feels, not how long they live.

Statistical vs. clinical meaning

Medium-sized pooled effect, but the best-controlled trial found none.

Safety implication

None for this score.

Study	Result	People	Product
¹¹	Pooled d = 0.61 (0.41-0.81) favouring mistletoe.	26 publications in cancer patients	Mistletoe extracts
²⁷	No significant difference between mistletoe and placebo in quality of life (numbers not in the abstract).	290 people with advanced pancreatic cancer	Subcutaneous mistletoe vs placebo

^{11 27 13 10}

▼

Cancer-related fatigue score

Lowered in trials

A rating of how tired a person feels because of cancer or its treatment.

Low certainty

Results and what it means

Why it was measured

A major symptom in cancer.

Statistical vs. clinical meaning

Moderate effect size but high heterogeneity and high risk of bias.

Safety implication

None identified from this measure.

Study	Result	People	Product
²¹	SMD -0.48 (-0.82 to -0.14) in randomised trials.	12 randomised trials, 1494 people	Mistletoe extracts

²¹

↕

Cytokines (immune signalling proteins such as TNF-alpha, IL-5, IL-13)

Mixed results in trials

Small proteins released by immune cells that coordinate inflammation and immune responses.

Not enough evidence

Results and what it means

Why it was measured

Used to show immune activation.

Statistical vs. clinical meaning

Inconsistent and not tied to health outcomes.

Safety implication

Immune activation could in theory worsen immune-driven disease; observational data in autoimmune disease are reassuring but not conclusive (see safety).

Study	Result	People	Product
⁸	TNF-alpha release by blood cells rose after the lectin-rich extract (week 25); IL-5 and IL-13 fell after the viscotoxin-rich extract. Placebo group also changed over time.	47 healthy volunteers	Iscador Quercus or Iscador Pinus vs saline, 12 weeks
¹⁰	No significant change in TNF-alpha or IL-2.	32 gastric cancer patients	abnobaVISCUM Quercus

^{8 10}

Safety

What studies and official sources say about side effects, medicines and who should check first. Each point shows what kind of evidence it comes from.

Main points to know 6

Eating the plant, the berries or drinking mistletoe tea is dangerous. This is not the same thing as the injected extracts.. Poison Control reports serious poisonings and deaths from European mistletoe (Viscum album), usually from concentrated home use such as brewing it as tea. The NCI says mistletoe plants and berries are considered poisonous. Do not eat the berries or leaves, do not make tea, and keep it away from children and pets. Pharmacy injectable extracts are a different, processed prescription product; the safety record of an injection says nothing about home preparations. Authoritative guidance ^{22 16}
American mistletoe (Phoradendron) is a different plant that seems less toxic. A review of 92 accidental exposures to American mistletoe, mostly toddlers, found symptoms in 14 (mild stomach upset, drowsiness and one seizure) and no heart effects. That does not show that European mistletoe is safe to eat, and Poison Control says the European species has caused deaths. Case series ^{23 22}
Injected extracts: local reactions, fever and flu-like symptoms are common; anaphylaxis is reported. NCI lists soreness and inflammation at the injection site, headache, fever and chills as common, and says a few cases of severe allergic reaction including anaphylactic shock have been reported. Two case reports (2021, 2024) describe anaphylaxis after a subcutaneous mistletoe injection; in one the shock was nearly masked by a carcinoid syndrome. Cochrane found side effects usually few and dose-dependent. No frequency of anaphylaxis is given in the sources read. Authoritative guidance ^{16 9 1 7}
Mistletoe is not a cancer cure and is not approved by the FDA for cancer. The FDA has not approved mistletoe extract for cancer or any other condition (NCI). Reviews found the best-quality trials do not show a survival benefit. Using it instead of, or delaying, standard treatment could be harmful. Talk to the cancer team before any use. Authoritative guidance ^{15 3 6}
Immune-modulating drugs and autoimmune disease: limited, mainly industry-linked, observational data. A registry study of 106 cancer patients with autoimmune disease reported no flares in 30 people on long-term therapy; a 16-person pilot found no difference in adverse events when mistletoe was added to checkpoint inhibitors. Both are small, observational and linked to mistletoe makers. They cannot rule out an interaction. Cohort study ^{19 25}
Pregnancy and breastfeeding: no safety information found. No source read gave pregnancy or breastfeeding safety data for mistletoe. LactMed was not read. Treat as unknown and ask a doctor. Insufficient ¹⁶

Side effects 6

Effect	How often	Severity and recovery	Evidence
Soreness, redness or hardening at the injection site Listed by NCI as the commonest effect. No frequency was found.	Not established	mild Usually settles; not described in detail in the sources read	Authoritative guidance ^{16 7}
Headache, fever, chills, tiredness, nausea (flu-like symptoms) A study of intravenous fever therapy appeared in the search but was not read.	Not established	mild Not described	Authoritative guidance ^{16 15}
Severe allergic reaction (anaphylaxis) NCI says 'a few cases' have been reported; no frequency given.	Not established	serious Life-threatening in one 2024 case report; not detailed in the 2021 case (title only)	Case report ^{9 1 16}
Higher eosinophil count (a type of white blood cell) Seen in two trials; MISTRAL found no link to any clinical effect.	Not established	unknown Not described	Controlled trial ^{10 27}
Stopping treatment because of adverse events or grade 3/4 toxicity Two of seven randomised trials around cancer surgery reported this; the review saw no overall safety signal.	Not established	moderate Not described	Meta-analysis ²
Seizure in a toddler after eating American mistletoe Unwitnessed exposure; different species; the link to the plant is unclear.	1 of 92 exposures (American mistletoe, Phoradendron)	serious Not stated	Case series ²³

Liver

NCI reports that high doses of recombinant (lab-made) mistletoe lectin caused reversible liver injury in some cases; that product is not a mistletoe extract and is not sold. The gastric cancer pilot found no effect on liver tests. We did not find a published case of liver injury from commercial extracts in the sources read, but the NIH LiverTox page for mistletoe was not read, so we cannot say what it concludes. ^{16 10}

How often. No frequency can be given. Not finding reports is not proof of safety.

Monitoring. No agency monitoring advice was found. Anyone with liver disease should ask their cancer team or doctor first.

This is a safety connection. It is not evidence that Mistletoe supports liver health.

Medicines and supplements 5

With	Why it matters	Importance	Evidence	What to do
Immune checkpoint inhibitors (for example nivolumab, pembrolizumab, ipilimumab) prescription	Theory: both act on the immune system.	A 16-person observational pilot (9 with mistletoe) found no difference in adverse event rates; the authors said immune interactions cannot be excluded.	Cohort study Very low certainty ²⁵	Tell the oncology team before any mistletoe use.
Chemotherapy and radiotherapy prescription	Not established. NCI says mistletoe may interfere with standard treatment or be harmful alongside it (general caution; summary-only, from our earlier summary).	No specific interaction was identified in the sources read.	Authoritative guidance Not enough evidence ¹⁶	Do not start mistletoe without the cancer team knowing.
Immunosuppressant medicines (transplant or autoimmune drugs) prescription	Theory: an immune-stimulating product could oppose drugs that suppress the immune system.	No study of this was found.	Pharmacological theory Not enough evidence ¹⁸	Ask the prescriber first.
Autoimmune disease itself (Hashimoto's, psoriasis, ulcerative colitis, Graves') prescription	Theory: immune activation could trigger flares.	Observational: no flares in 30 long-term users (106 patients), study linked to mistletoe makers.	Cohort study Very low certainty ¹⁹	Ask the specialist who treats the autoimmune condition.
Medicines that lower blood pressure, or any medicine for seizures prescription	Not studied. NCI lists high blood pressure and epilepsy only as traditional uses; the sources read give no interaction.	No interaction documented in the sources read.	Traditional use Not enough evidence ^{15 17}	Do not use home mistletoe preparations; ask a doctor.

Who should check first 5

Situation	Advice	Evidence
Eating mistletoe berries, leaves or making tea	Do not. Serious poisonings and deaths are reported with European mistletoe.	Authoritative guidance ^{22 16}
Anyone who has had an allergic reaction to a mistletoe product	Seek advice from the prescribing doctor; anaphylaxis has been reported.	Case report ^{9 1}
Using mistletoe in place of standard cancer treatment, or delaying treatment	Not supported by the evidence; the best-quality trials show no survival benefit.	Systematic review ^{3 6}
Pregnancy, breastfeeding, children	No safety data found in the sources read. Avoid unless a doctor advises otherwise.	Insufficient ¹⁶
Neuroendocrine tumour or carcinoid syndrome	A 2024 case report showed anaphylaxis can be masked by carcinoid symptoms. Tell the team.	Case report ⁹

Overdose, product quality and regulators

Summary. The whole plant and berries are poisonous. The injected extracts are processed and given under medical supervision. Lectins and viscotoxins are the suspected toxic proteins, but the sources read give no human toxic dose.

Animal. Not read.

Human doses studied. Not summarised here; dosing is not covered on this page.

High dose or long term signals. High doses of a recombinant lectin (not an extract) caused reversible liver injury in some cases (NCI).

Overdose response. Not described in the sources read. For any swallowed mistletoe call a poison centre (US: 1-800-222-1222).

Genotoxicity. Not read.

Toxic plant parts. Berries and leaves are called poisonous by NCI; Poison Control links deaths to tea. Which part is most toxic was not stated in the sources read.

Mistletoe products differ by species, host tree, harvest time, extraction and maker. This changes composition and probably effects.

Huge variety of products and schedules. A review of 102 publications found a very wide range of extract types, host trees, routes and schedules, with no link between preparation and cancer type. ²⁴

Composition varies. NCI and a chemistry review say composition depends on host tree, harvest time, preparation and maker; some products are homeopathic-style and not chemically standardised. ^{16 17}

Body	Action	Date
US Food and Drug Administration (via NCI) (United States)	FDA has not approved mistletoe extract as a treatment for cancer or any other condition. Injectable mistletoe is not commercially available in the US. source	2023-2024 (NCI pages)

When to get medical help

Trouble breathing, swelling of the face or throat, hives or dizziness after any mistletoe injection: call emergency services (possible anaphylaxis).
Anyone (child, adult or pet) who has swallowed mistletoe berries, leaves or tea and has vomiting, severe stomach pain, confusion, drowsiness, fast or slow heartbeat or a seizure: call a poison centre or emergency services.
High fever, severe chills or a spreading red, hot, painful injection site.
New yellow skin or eyes, dark urine or pale stools.

Stop the supplement and contact a clinician or emergency service. In the US, Poison Control is 1-800-222-1222.

General information only, not medical advice. Ask a clinician or pharmacist before use, especially with medicines, in pregnancy or with a health condition. See the Natural Remedy Safety guide.

Frequently asked questions

What is European mistletoe?

A semi-parasitic evergreen plant (Viscum album) that grows on trees. In Europe, injectable extracts are prescription medicines used as an add-on in cancer care. The raw plant and berries are poisonous.

^{4 16}

Can mistletoe cure cancer?

No. The best-designed trials do not show that it helps people live longer, and the FDA has not approved it for cancer. It should never replace standard treatment. Ask your cancer team before using any mistletoe product.

^{3 6 15}

Does mistletoe help people live longer?

Not reliably. All studies pooled looked good for mistletoe, but the better-designed randomised studies did not show a significant benefit, and their range was very wide.

^{6 7}

Does it improve quality of life?

It may, with low certainty. Pooled studies suggest a medium-sized improvement, and breast cancer trials were rated moderate certainty. But most studies are open-label, and a placebo-controlled pancreatic cancer trial found no benefit.

^{11 13 27}

Is mistletoe tea safe?

No. Poison Control links serious poisonings and deaths to European mistletoe, usually concentrated preparations such as tea. Tea is not the studied injectable extract.

²²

What if a child or pet eats a berry?

Call a poison centre or emergency services (US poison help line: 1-800-222-1222). American mistletoe seems milder, but you cannot assume the plant is American.

^{22 23}

What are the side effects of the injections?

Soreness at the site, headache, fever, chills and tiredness are common. A few severe allergic reactions have been reported, including anaphylaxis. Call emergency services for trouble breathing or swelling after an injection.

^{16 9 1}

Can I use mistletoe with immunotherapy or if I have an autoimmune disease?

Ask your specialist. Small observational studies, some linked to mistletoe makers, found no extra problems, but they cannot rule out interactions.

^{25 19}

Is it safe in pregnancy or breastfeeding?

No safety information was found. Treat it as unknown and ask a doctor.

¹⁶

Does it affect the liver?

NCI reports reversible liver injury only with high doses of a lab-made lectin that is not sold. We found no case with commercial extracts, but the LiverTox page was not read. Ask a doctor if you have liver disease.

^{16 10}

Why do products differ?

Extracts vary by host tree, harvest time, fermentation and maker. One review found no consistent link between product and cancer type, so results of one product cannot be assumed for another.

^{24 16}

Where can I find out about amounts or products?

Ask your cancer doctor or pharmacist. Amounts depend on the product and the person and are decided by the prescriber.

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Editorial transparency

Written by: AlternativeMed editorial team. Research compiled with AI assistance, then checked against PubMed records.
Medical review: None. This page has not been reviewed by a physician or pharmacist.
First published: 2026-10-25
Last substantive update: 2026-10-25
How we research: We started from our earlier evidence summary for mistletoe, read the National Cancer Institute PDQ pages and the Poison Control article, and read PubMed abstracts for the studies cited. Plant names were checked in GBIF and NCBI Taxonomy. Not read: LiverTox, LactMed, NCCIH, EMA documents, manufacturer prescribing information. Most studies were read as abstracts only; one case report has a title only. Certainty ratings are the compiler's reading, using the reviewers' own GRADE where given.
How we rate evidence: See "How we rate evidence" in the Evidence tab.
Independence: No product is promoted on this page. No affiliate links are shown.

Sources 27

Each source was opened and checked. Where we read only the abstract, it says so. The small numbers in the text point here.

Casetti F, Rafei-Shamsabadi D, Müller S. Grade II-anaphylaxis after subcutaneous injection of mistletoe extract. Contact Dermatitis. 2021. PMID 33963569. DOI 10.1111/cod.13880. (title-only)
Cogo E, Elsayed M, Bhardwaj S, et al.. Mistletoe Extracts during the Oncological Perioperative Period: A Systematic Review and Meta-Analysis of Human Randomized Controlled Trials. Curr Oncol. 2023. PMID 37754510. DOI 10.3390/curroncol30090595. (abstract)
Freuding M, Keinki C, Micke O, et al.. Mistletoe in oncological treatment: a systematic review. Part 1: survival and safety. J Cancer Res Clin Oncol. 2019. PMID 30673873. DOI 10.1007/s00432-018-02837-4. (abstract)
GBIF Secretariat. GBIF backbone match: Viscum album L.. GBIF API. 2026. (full-text)
GBIF Secretariat. GBIF backbone match: Phoradendron leucarpum. GBIF API. 2026. (full-text)
Hofinger J, Kaesmann L, Buentzel J, et al.. Systematic assessment of the influence of quality of studies on mistletoe in cancer care on the results of a meta-analysis on overall survival. J Cancer Res Clin Oncol. 2024. PMID 38679615. DOI 10.1007/s00432-024-05742-1. (abstract)
Horneber MA, Bueschel G, Huber R, et al.. Mistletoe therapy in oncology. Cochrane Database Syst Rev. 2008. PMID 18425885. DOI 10.1002/14651858.CD003297.pub2. (abstract)
Huber R, Classen K, Werner M, Klein R. In vitro immunoreactivity towards lectin-rich or viscotoxin-rich mistletoe (Viscum album L.) extracts Iscador applied to healthy individuals. Arzneimittelforschung. 2006. PMID 16927525. DOI 10.1055/s-0031-1296811. (abstract)
Kaemmerer D, Hommann M. [Anaphylactic shock after mistletoe therapy]. Inn Med (Heidelb). 2024. PMID 39019992. DOI 10.1007/s00108-024-01746-8. (abstract)
Kim KC, Yook JH, Eisenbraun J, et al.. Quality of life, immunomodulation and safety of adjuvant mistletoe treatment in patients with gastric carcinoma - a randomized, controlled pilot study. BMC Complement Altern Med. 2012. PMID 23033982. DOI 10.1186/1472-6882-12-172. (abstract)
Loef M, Walach H. Quality of life in cancer patients treated with mistletoe: a systematic review and meta-analysis. BMC Complement Med Ther. 2020. PMID 32690087. DOI 10.1186/s12906-020-03013-3. (abstract)
Loef M, Walach H. Survival of Cancer Patients Treated with Non-Fermented Mistletoe Extract: A Systematic Review and Meta-Analysis. Integr Cancer Ther. 2022. PMID 36324298. DOI 10.1177/15347354221133561. (abstract)
Loef M, Paepke D, Walach H. Quality of Life in Breast Cancer Patients Treated With Mistletoe Extracts: A Systematic Review and Meta-Analysis. Integr Cancer Ther. 2023. PMID 37888846. DOI 10.1177/15347354231198074. (abstract)
NCBI PubChem. PubChem: Quercetin. PubChem API. 2026. (full-text)
National Cancer Institute. Mistletoe Extracts (PDQ), Patient Version. cancer.gov PDQ. 2023. (full-text)
National Cancer Institute. Mistletoe Extracts (PDQ), Health Professional Version. cancer.gov PDQ. 2024. (full-text)
Nazaruk J, Orlikowski P. Phytochemical profile and therapeutic potential of Viscum album L.. Nat Prod Res. 2016. PMID 25813519. DOI 10.1080/14786419.2015.1022776. (mixed)
Oei SL, Thronicke A, Schad F. Mistletoe and Immunomodulation: Insights and Implications for Anticancer Therapies. Evid Based Complement Alternat Med. 2019. PMID 31118962. DOI 10.1155/2019/5893017. (abstract)
Oei SL, Thronicke A, Kröz M, et al.. Use and Safety of Viscum album L Applications in Cancer Patients With Preexisting Autoimmune Diseases: Findings From the Network Oncology Study. Integr Cancer Ther. 2019. PMID 30808274. DOI 10.1177/1534735419832367. (abstract)
Paramonov AS, Lyukmanova EN, Tonevitsky AG, et al.. Spatial structure and oligomerization of viscotoxin A3 in detergent micelles: Implication for mechanisms of ion channel formation and membrane lysis. Biochem Biophys Res Commun. 2021. PMID 34781057. DOI 10.1016/j.bbrc.2021.11.022. (abstract)
Pelzer F, Loef M, Martin DD, Baumgartner S. Cancer-related fatigue in patients treated with mistletoe extracts: a systematic review and meta-analysis. Support Care Cancer. 2022. PMID 35239008. DOI 10.1007/s00520-022-06921-x. (abstract)
Poison Control (US national poison centers). Is mistletoe poisonous?. poison.org. . (full-text)
Spiller HA, Willias DB, Gorman SE, et al.. Retrospective study of mistletoe ingestion. J Toxicol Clin Toxicol. 1996. PMID 8699554. DOI 10.3109/15563659609013810. (abstract)
Staupe H, Buentzel J, Keinki C, et al.. Systematic analysis of mistletoe prescriptions in clinical studies. J Cancer Res Clin Oncol. 2023. PMID 36481925. DOI 10.1007/s00432-022-04511-2. (abstract)
Thronicke A, Steele ML, Grah C, et al.. Clinical safety of combined therapy of immune checkpoint inhibitors and Viscum album L. therapy in patients with advanced or metastatic cancer. BMC Complement Altern Med. 2017. PMID 29237435. DOI 10.1186/s12906-017-2045-0. (abstract)
Tröger W, Galun D, Reif M, et al.. Viscum album [L.] extract therapy in patients with locally advanced or metastatic pancreatic cancer: a randomised clinical trial on overall survival. Eur J Cancer. 2013. PMID 23890767. DOI 10.1016/j.ejca.2013.06.043. (abstract)
Wode K, Björ O, Klein R, et al.. Mistletoe extract in patients with advanced pancreatic cancer: Health-related quality of life in a double-blind, randomized, placebo-controlled trial (MISTRAL). Palliat Med. 2026. PMID 42059487. DOI 10.1177/02692163261437609. (abstract)

Education, not medical advice. This page is for general information. It does not diagnose or treat any condition and is not a substitute for care from a qualified health professional. Natural does not automatically mean safe. Ask a clinician or pharmacist before changing your care, especially if you take medication, are pregnant or breastfeeding, or have a health condition.