Remedies › Mistletoe extract

Mistletoe extract (Viscum album)

Also called European mistletoe, Viscum album, Iscador, Iscar, Helixor, abnobaVISCUM, Iscucin, Lektinol, Eurixor, Isorel.

Mistletoe extract is made from European mistletoe (Viscum album), a plant that grows on trees such as apple, oak, pine and fir. It is not a supplement: the products studied are prescription injections, given under the skin, into a vein or into the bladder, mostly in German-speaking countries, where they are among the most prescribed cancer drugs and are rooted in anthroposophic medicine. The plant and berries themselves are poisonous. American mistletoe (Phoradendron) is a different plant and is not covered here.

What it has been studied for

Beyond Google: what a search won’t show you

Places a normal search rarely reaches: trial registries, NIH grant records, FDA adverse-event data and patent offices. Each item links to its primary record.

Hidden contradiction
Pancreatic cancer: the open trial said mistletoe nearly doubled survival; the blinded trial found nothing
2013 vs 2024
A 2013 Serbian trial with no placebo reported median survival of 4.8 vs 2.7 months (hazard ratio 0.49; PMID 23890767). The Swedish MISTRAL trial, double-blind with placebo injections, found 7.8 vs 8.3 months (hazard ratio 1.13; PMID 38915151) and no quality-of-life gain. Most web pages about mistletoe still quote the first result.
Hidden contradiction
Melanoma: observational data said 59% less cancer death; the randomized trial found no benefit
2004 vs 2005
A manufacturer-era record review of 686 patients reported a tumour-related death hazard ratio of 0.41 with Iscador (PMID 15727163). The EORTC/German Cancer Society randomized trial of 830 patients, followed for 8 years, found hazard ratios of 1.32 for relapse and 1.21 for death with Iscador M vs observation (PMID 14746858). A 2024 Jena analysis found the same pattern across all cancers: benefit in low-quality studies, none in the best randomized ones (PMID 38679615).
Terminated trial, no results
Largest randomized bladder cancer trial of mistletoe (TIM, abnobaVISCUM 900 vs mitomycin C)
started 2015, ended early 24 April 2026
Sponsored by Abnoba GmbH; 174 patients enrolled in a phase 3 trial against standard bladder chemotherapy. Stopped because recruitment could not be completed (the registry says not for safety). The protocol was published in 2015 and 2016, but no results are posted on ClinicalTrials.gov or in the EU register (EU CT 2023-503718-66-00), and we found no results paper. It ended only in April 2026, so results may still appear.
Unpublished trial (public money)
Iscar (US Iscador) for stage IV lung cancer, Thomas Jefferson University
2001-2004
NIH RePORTER shows $378,250 in National Center for Complementary and Alternative Medicine grants (2001 and 2003). The registry lists 36 participants and completion in 2004; a related entry (NCT00052325, NCI collaborator) has been 'unknown status' since 2013. We found no publication. A second small US Iscar trial (NCT00283478, Kentuckiana Cancer Institute, 20 patients, completed 2007) is also unpublished.
Stalled registrations
Two Iscador Qu studies in 520 pancreatic and colorectal cancer patients (IFAG / Hiscia)
registered 2011, last updated 2013
The pancreatic study lists 220 enrolled and an end date of June 2016; the colorectal study (NCT01448655) planned 300. Both are run by the Iscador maker's research society and contract research firm; status unknown, no results posted, no linked paper.
Unpublished randomized study
Iscador P in breast cancer, Heidelberg University (Weleda and Society for Cancer Research as collaborators)
1999-2009
Registered as randomized with 114 participants. The team published that only 29 of 521 eligible women would accept randomization (PMID 15249749) and later a non-randomized comparison of 66 (PMID 18334811); we found no paper reporting the randomized study.
Registry results not posted
None of 25 registered mistletoe trials has results on ClinicalTrials.gov
checked 2026-10-28
Including the completed Johns Hopkins intravenous trial (NCT03051477, 21 patients), which did publish in a journal (PMID 36860652), and MISTRAL. Results for mistletoe live only in journals, where positive studies are more likely to appear.
FDA adverse-event reports
290 reports to the FDA drug database name a mistletoe product; none in the supplement database
2004-2026
We downloaded every FAERS report naming Iscador, Helixor, abnobaVISCUM, Lektinol, Viscum album or mistletoe: 290 reports, mostly from Germany (73) and Switzerland (40). Mistletoe was a suspected cause in 33, never the only product listed. Those 33 include 13 hospital stays, 3 deaths in patients also taking other drugs, 2 anaphylactic-shock reports (possibly one patient), and 3 French reports of bleeding with a high INR in patients on warfarin. The supplement database (CAERS) has no report naming mistletoe. A report is not proof the product caused the problem.
Regulatory status
A reimbursed prescription drug in Germany, not approved in the US
current
The US National Cancer Institute states that mistletoe extract injections are not approved by the FDA as a treatment for cancer and are not sold as a drug in the US, while in Europe they are among the most prescribed drugs for cancer patients. A German health technology assessment notes that statutory health insurance pays for lectin-standardised extracts only in palliative care to improve quality of life (PMID 21289969).
Patent
US 7,550,159: "Orally ingestible preparation of mistletoe lectins and method"
2009
Claims an oral form of mistletoe lectins for treating cancer, related to New Zealand patent NZ526202. Every trial we found used injections, infusions or bladder instillations; a patent is a legal claim, not evidence.
Hidden in a mixture
A children's chemotherapy trial sponsored by a mistletoe maker: the published abstract never says mistletoe
ran 2005 to 2012, published 2022
The ISRCTN record, sponsored by Helixor, describes a 340-child randomized trial of anthroposophic supportive medicine that includes mistletoe, added to cancer treatment. The results appeared ten years after it ended (BMC Cancer 2022, PMID 35698215, 288 children analyzed) as a trial of 'integrative medicine', with no difference in chemotherapy toxicity or 5-year survival. The abstract does not name mistletoe or cite the registry number, so a mistletoe search does not connect the two.

Sources searched on 2026-10-28: ClinicalTrials.gov (25 mistletoe trials), NIH RePORTER, FDA FAERS and CAERS (openFDA), Europe PMC preprints, Europe PMC patents, J-STAGE (Japanese journals), NCI PDQ, EU Clinical Trials Information System (CTIS), ISRCTN registry. Where we look

Safety notes

Skin reactions where the extract is injected are the most common side effect: 66% of patients on mistletoe vs 1% on placebo in the largest blinded trial. They also make it almost impossible to keep trials blind. Source
Flu-like symptoms and fever rise with the dose; allergic reactions occur occasionally, and high doses of the isolated lectin caused reversible liver toxicity in some patients. Source
Severe allergic reactions, including anaphylaxis, have been reported after injections. Source
Starting at doses above the recommended low starting dose was linked with far more side effects (20.7% vs 0.8%) in 1,361 patients. Source
Possible interaction with warfarin: a patient injecting mistletoe on his own during chemotherapy had a dangerously high INR and gut bleeding. Three French reports to the FDA describe the same pattern. Source
Intravenous use is off-label and riskier: in US and German dose-finding trials, side effects included grade 3 events, an allergic reaction at the highest dose, and, combined with gemcitabine, severe drops in blood counts and one acute kidney failure attributed to mistletoe. Source
In one lymphoma patient, lymphoma deposits grew at the injection sites; several authors advise caution in lymphomas and leukaemias. Source
The plant and its berries are poisonous; the studied products are prescription injections, not teas or home-made extracts. The US FDA has not approved mistletoe for cancer or any other condition (NCI PDQ).

Possible links

Where one finding points to others. These are leads for research, not conclusions.

Other conditions

Diabetes and blood sugar 46 papers Mostly lab and animal work, plus Korean and African mistletoe species. Not yet read by us. See on PubMed
High blood pressure 39 papers A traditional use; one registered trial of a homeopathic mother tincture for hypertension in India (NCT01527760). Not yet read by us. See on PubMed
Arthritis and rheumatic disease 26 papers Not yet read by us. See on PubMed
HIV 14 papers Small studies from the 1990s and 2000s. Not yet read by us. See on PubMed
Hepatitis C 11 papers A 2001 study of 25 patients found no change in viral load or liver enzymes, though tiredness improved. See on PubMed

Same mechanism

Mistletoe lectins (ribosome-inactivating proteins) 2,157 papers The main active proteins kill cells and stimulate immune cells in the lab. A recombinant version, aviscumine, was tested as a drug in EORTC phase 1 trials; best response was stable disease. See on PubMed Source
Immune stimulation (natural killer cells) 167 papers Trials report changes in immune cells; a randomized trial found less drop in natural killer cell activity after surgery. Whether this changes outcomes is unproven. Source
Fever induction Some clinics give high intravenous doses to provoke fever; 76% of 59 patients reached 38.5 C or more in one retrospective study. Source

Combinations

Mistletoe with chemotherapy 403 papers The most studied setting; see the chemotherapy page. See on PubMed
Mistletoe with immunotherapy (checkpoint inhibitors) 10 papers Registry studies funded by mistletoe makers report longer survival in lung cancer; no randomized trial yet. A Basel trial (NCT06408688) and a Korean trial (NCT06920810) are recruiting. See on PubMed
Mistletoe with hyperthermia or high-dose vitamin C 52 papers Common in private integrative clinics; evidence is case reports and retrospective cohorts. See on PubMed

Who does the research

G. S. Kienle 37 papers Institute for Applied Epistemology and Medical Methodology (IFAEMM), Freiburg; author of most positive systematic reviews.
F. Schad 32 papers Network Oncology registry, Research Institute Havelhöhe, Berlin (anthroposophic hospital); the registry survival studies.
A. Büssing 30 papers University of Witten/Herdecke; immune studies and meta-analyses.
J. Beuth 23 papers University of Cologne institute for evaluating naturopathic methods; lectin-standardised extract studies.
J. Hübner group (Freuding M., Hofinger J.) 4 papers University Hospital Jena; the critical systematic reviews that found benefit disappears in high-quality studies.

Who pays for it

Mistletoe manufacturers (Helixor Heilmittel, Abnoba / LB ABNOBA, Iscador AG, WALA) 9 papers
Verein für Krebsforschung (Society for Cancer Research), Arlesheim 2 papers
US National Cancer Institute (NIH) 4 papers
Deutsche Krebshilfe 2 papers

Counts are papers in our two PubMed lists (960 unique records) where PubMed records a funder; most list none. Conflict statements add more: the authors of the 2022 fatigue meta-analysis state that the Society for Cancer Research is a minority shareholder of Iscador AG and that two authors work for it or for Iscador AG (PMID 35239008); the 2018 Serbian trial was financed by that Society and Helixor (PMID 30247950); and the Cochrane authors received research money and fees from manufacturers (PMID 18425885). Registry sponsors on ClinicalTrials.gov include Abnoba GmbH, Abnoba Korea, IFAG AG / Hiscia (Iscador) and Weleda. The negative MISTRAL trial was investigator-initiated, run by Swedish university hospitals, and its authors declared no competing interests (PMID 42934316).

What people report

We read public first-person posts and counted every outcome, good or bad. 25 reports, read on 2026-10-28; 5 mention side effects.

14Helped
3No effect
1Got worse
3Mixed
4Too early

Why these counts prove nothing on their own: people who post are not a random sample, most take other treatments at the same time, and nobody checks the diagnosis. We show them because they tell researchers what to test next.

Read all 25 reports

Helped Has injected Iscador for more than four years after a late diagnosis and has passed the five-year mark; feels it is helping. Breast Cancer Now forum, 2010-10-02 (Survival alongside standard treatment; poster does not claim proof.)
Helped Reports no side effects and remission seven and a half years after a poor-prognosis diagnosis; later adds she cannot know whether Iscador made the difference. Breast Cancer Now forum, 2010-10-03 (Remission after full standard treatment; poster acknowledges uncertainty.)
Helped Says her mother took mistletoe for ten years after bowel cancer surgery, declined chemotherapy, and has had no recurrence in twenty years. Breast Cancer Now forum, 2010-10-03 (Second-hand report from a daughter; stage and pathology not given.)
Too early Started Iscador privately at a low series because of sensitivities; tolerating it so far and has reached the expected skin reaction. Side effects: injection-site red mark (the intended reaction). Breast Cancer Now forum, 2010-12-03 (No cancer outcome reported.)
Helped Took letrozole plus Iscador for five years after a 2006 bone-metastasis diagnosis and reports no cancer since. Breast Cancer Now forum, 2015-11-26 (Letrozole is an effective standard drug and is a strong confounder.)
Helped Started Iscador during chemotherapy and says it eased the side effects; tumour free about five years later. Breast Cancer Now forum, 2017-09-24 (Lives in Switzerland where insurance covers it; outcome self-assessed.)
Too early Gave the first mistletoe injection the day before posting and had not yet had the expected skin reaction. Breastcancer.org community, 2025-11 (Just started.)
Helped Had stopped chemotherapy because of severe gut pain; after starting mistletoe injections she restarted, had no more stomach pain and finished the course. HealthUnlocked, 2022-09-14 (Single course; she does not expect mistletoe to treat the cancer itself.)
Helped Has just started mistletoe and says it is working well for her condition; main complaint is the practitioner's cost. HealthUnlocked, 2018-09-07 (Very early report; no measure given.)
Helped Uses mistletoe injections alongside palbociclib and letrozole and finds them helpful. HealthUnlocked, 2021-08-26 (No measure given; several treatments at once.)
Helped Injected mistletoe throughout chemotherapy on her doctor's advice to ease side effects and feels it was an important part of coping well. HealthUnlocked, 2021-03 (Same person also reported this in a later thread; counted once.)
Mixed Was cancer free for five and a half years before a recurrence; stopped because of injections, prescription hassle and cost, and has not restarted. Side effects: discomfort of frequent injections. HealthUnlocked, 2021-05-13 (Does not attribute either the remission or the recurrence to mistletoe.)
Helped Took Iscador for about three years before radiotherapy and credits it as one of the things that kept the cancer stable; would use it again. HealthUnlocked, 2020-02-03 (Says himself it is impossible to tell which treatment helped.)
No effect PSA rose from 17.6 to 31.1 and a scan showed more cancer activity during two months of Iscador, so he stopped it. HealthUnlocked, 2019-04 (No standard treatment; short trial.)
Mixed PSA fell to 0.1 with mistletoe among about ten concurrent therapies, mostly credited to hyperthermia and hormone therapy; the colon cancer later spread again. HealthUnlocked, 2019-05 (Mistletoe's part cannot be separated.)
Too early After BCG, had three weeks of Iscador by several routes at a Swiss clinic; strong injections brought high fevers. Too early to judge. Side effects: high fever after injections (intended by the clinic). Inspire, 2013-03-21 (Replies are members-only and were not read.)
Mixed Says Iscador did not stop her mother's ovarian cancer but did give her pain relief in her last days. Melanoma Research Foundation forum, 2011-08-17 (Second-hand family report.)
Helped Reports great results from mistletoe; says her oncologist could not explain the improvement. Inspire, 2019-03-14 (No details of treatment or measures.)
Too early After six weeks she cannot tell whether it helps; a strong reaction left a sore, itchy lump and that area became hard to inject. Side effects: sore, itchy lump at the injection site, skin that resisted the needle. Inspire, 2019-05-05 (Early report.)
Worse Tried mistletoe a few years earlier and quit because her CA-125 tumour marker rose. Inspire, 2019-05-17 (Marker change only; timing and other treatment not given.)
Helped After a year of mistletoe injections and infusions, believes it is a big part of having had no evidence of disease for almost a year. Side effects: scarring at injection sites. Inspire, 2019-06-16 (Many concurrent therapies; prior treatment not described.)
No effect Takes one homeopathic mistletoe tablet a day; feels well but cannot say whether it makes any difference. HealthUnlocked, 2021-02 (Homeopathic dilution, not the extract studied in trials.)
Helped Her first scan after starting mistletoe showed smaller tumours and healing bone metastases and she feels great, though her tumour marker has climbed again. HealthUnlocked, 2021-02 (Started anastrozole a few months earlier, which can explain the scan; marker rising.)
Helped Used mistletoe for a long time and feels it made her feel better through treatment; stopped over cost and medication changes. HealthUnlocked, 2021-03 (Not used to treat the cancer itself.)
No effect Made his own mistletoe tincture with other herbs over a summer; PSA kept climbing. HealthUnlocked, 2019-04-06 (Home-made oral tincture, not a pharmaceutical extract.)

Checked against PubMed on 2026-10-28.