Remedies › Ivermectin
Ivermectin (antiparasitic drug)
Also called Stromectol, Mectizan, Soolantra, Sklice, Ivomec.
Ivermectin is a prescription antiparasitic drug: in the US, Stromectol tablets treat river blindness and threadworm infection, a cream (Soolantra) treats rosacea and a lotion (Sklice) treats head lice. Its discovery shared the 2015 Nobel Prize in medicine. It is also sold for animals as paste, pour-on and injection. It became a cancer remedy online after the COVID-19 period, often in protocols that pair it with mebendazole or fenbendazole.
What it has been studied for
Beyond Google: what a search won’t show you
Places a normal search rarely reaches: a retraction notice, trial registries, the FDA's two adverse-event databases and preprint servers. Each item links to its primary record.
- Retracted paper
The largest human report on ivermectin for cancer was retracted
published June 2026, expression of concern June 2026, retracted October 2026
A survey of 197 people prescribed compounded ivermectin (25 mg) with mebendazole (250 mg) through a US telemedicine platform, from the McCullough Foundation. The journal first issued an expression of concern, then listed questions about the self-reported 'clinical benefit' measure, the timing of baseline, the dose analysis and the handling of people lost to follow-up or on other cancer treatment. It retracted the paper in October 2026 (notice PMID 42823188), citing methodological and analytical problems; it made no allegation of misconduct.
- Trial recruiting, no results
Ivermectin plus immunotherapy in metastatic triple-negative breast cancer
started October 2023, last updated August 2026
Phase 1/2 trial (34 planned), ivermectin on days 1 to 3 of each week with balstilimab or pembrolizumab; primary outcomes side effects and response rate. Still recruiting; nothing posted and no paper in PubMed. It is the only registered human trial of ivermectin as a cancer treatment that has started.
- Trial not yet recruiting
University of Florida ICONIC trial: ivermectin with checkpoint drugs
registered 2026, start planned December 2026
80 planned, two ivermectin doses (200 or 400 micrograms per kg, days 1 to 3 weekly for 4 weeks). Its main outcome is an immune-cell marker in the blood, not tumor shrinkage or survival.
- Trial stopped, unpublished
Ivermectin and losartan for COVID-19 in people with cancer stopped for futility
2020 to 2022
Instituto do Cancer do Estado de Sao Paulo randomized 77 people with cancer and COVID-19; a futility analysis showed no difference between arms and the trial was terminated. No results were posted and no paper is in PubMed. It tested COVID-19 outcomes, not cancer.
- Registered study with unknown status
Florida clinic's 'atavistic chemotherapy' study listing ivermectin among dozens of anti-infectives
started 2011, last updated 2022
Registered by a private cancer clinic (250 planned) with ivermectin one of many antiparasitic, antifungal and antibacterial drugs. Status unknown since 2022; no results posted. A registration is not a finding.
- FDA adverse-event reports (drug database)
41 reports in the FDA's human drug database where ivermectin was given for a cancer
2008 to 2026, 18 of them received in 2025
Counted on 2026-10-28 from 399 reports that mention ivermectin and a cancer indication, keeping only those where ivermectin's own indication is a cancer: 24 serious, 13 with a hospital stay, 3 flagged as deaths, 26 naming it as the main suspect, 9 also listing fenbendazole. Reactions most often recorded: neurotoxicity (5), seizures (4), torsade de pointes (4), QT prolongation (4). Seven reports carry the code 'drug effective for unapproved indication' and six 'drug ineffective' or 'treatment failure'.
- FDA adverse-event reports (supplement database)
2 reports in the FDA's food and supplement database (CAERS)
2025 and 2026
One names an ivermectin product alone (unsteadiness, confusion, dizziness and toxicity, marked serious); the other a gut-flush product with ivermectin and fenbendazole (dizziness and headache, emergency-room visit). Neither records a cancer or a hospital stay.
- Preprint
'Ivermectin converts cold tumors hot' (mouse breast cancer)
2020
A bioRxiv preprint reporting that ivermectin made mouse breast tumors respond to a checkpoint drug. It is the lab idea behind both immunotherapy trials above; a mouse result, not a human one.
Sources searched on 2026-10-28: PubMed, ClinicalTrials.gov, Europe PMC preprints, Europe PMC patents, FDA CAERS (openFDA), FDA FAERS (openFDA), NIH RePORTER, J-STAGE, Publisher retraction notices. Where we look
Safety notes
- In a Merck study of 68 healthy adults, single doses up to 120 mg and 60 mg three times a week were well tolerated, up to 10 times the highest approved dose. Cancer protocols online often go higher, for months, in older and sicker people, which this study did not test. Source
- A 73-year-old with metastatic breast cancer who took high doses based on online information had seizures and respiratory failure and needed a ventilator; she recovered within 48 hours. Source
- A man with prostate cancer who alternated veterinary ivermectin and fenbendazole paste for 3 months developed severe liver injury; it resolved after he stopped both. Veterinary products are dosed for animals and are hard to measure for a person. Source
- A 2025 report from Beijing describes a death from ivermectin poisoning absorbed through the skin, with brain swelling in the later stage. Source
- Ivermectin is moved out of the brain by the P-glycoprotein pump, which many cancer drugs also use. In a dog lacking that pump, standard chemotherapy was more toxic (an animal case). Anyone on chemotherapy, immunotherapy or targeted drugs should tell their oncologist before taking it. Source
- The FDA's drug adverse-event database holds 41 reports (count on 2026-10-28) in which ivermectin was given for a cancer: 24 serious, 13 with a hospital stay, 3 flagged as deaths; the most common reactions were neurotoxicity, seizures and heart-rhythm problems (QT prolongation, torsade de pointes). Reports cannot prove that ivermectin caused anything.
Possible links
Where one finding points to others. These are leads for research, not conclusions.
Other conditions
- Rosacea 189 papers Approved in the US as a 1% cream (Soolantra). Not yet read by us. See on PubMed
- Scabies 733 papers A standard treatment for scabies in many countries, as tablets or cream. Not yet read by us. See on PubMed
- Head lice 141 papers Approved in the US as a 0.5% lotion (Sklice). Not yet read by us. See on PubMed
- COVID-19 795 papers Heavily studied in 2020 to 2022, including large randomized trials. Not yet read by us; a separate page is planned. See on PubMed
Same mechanism
- Wnt/beta-catenin signaling 16 papers Reviews cite lab studies in which ivermectin blocks this growth pathway in several cancer cell types (PMID 42217373). See on PubMed Source
- PAK1 and autophagy 33 papers Lab and mouse studies report that ivermectin lowers PAK1 and triggers autophagy in cancer cells. See on PubMed
- P-glycoprotein drug pump 40 papers Ivermectin blocks this pump in lab studies, which is why it is proposed to make chemotherapy-resistant cells sensitive again; the same pump is behind its toxicity risk with some cancer drugs. See on PubMed
Combinations
- Ivermectin with mebendazole or fenbendazole (online protocols) 11 papers The pairing behind the retracted 197-patient survey and two of the case reports; 9 of the FDA cancer reports also list fenbendazole. See on PubMed
- Ivermectin with immunotherapy 14 papers A 2020 bioRxiv preprint reported that ivermectin made breast tumors in mice respond to checkpoint drugs; the two registered human trials test this idea. See on PubMed
- Ivermectin with dichloroacetate 2 papers One three-patient case report from a Tokyo company (PMID 35265417). See on PubMed
Who does the research
- Y. Zhang 14 papers Appears on 14 papers; a common name in PubMed that may be several people. First affiliation listed: West China Hospital, Sichuan University (hematology).
Who pays for it
- National Natural Science Foundation of China 14 papers
- US National Cancer Institute (NIH) 11 papers
- Wellcome Trust 4 papers
Funding is listed only where PubMed records it; most ivermectin cancer papers list none, and none of the six human case reports lists a funder.
What people report
We read public first-person posts and counted every outcome, good or bad. 20 reports, read on 2026-10-28; 1 mention side effects.
- 10Helped
- 1No effect
- 1Got worse
- 4Mixed
- 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 20 reports
- Worse Took 70 mg ivermectin daily with mebendazole while waiting for chemotherapy; side effects were bad enough that he stopped after five days. Side effects: dizziness, brain fog, nausea, ringing in the ears. HealthUnlocked, 2026-03 (Dose far above approved human doses; outcome is side effects, not cancer response.)
- Helped Takes about 1 mg/kg five days a week as part of a combined approach and says the combination is working for him. HealthUnlocked, 2026-03 (On Pluvicto at the same time; no numbers given.)
- No effect After about four years with stage 4 disease, says ivermectin did not work for him and advises staying on standard treatment. HealthUnlocked, 2026-03 (No dose, dates or numbers given.)
- Helped Self-medicating with ivermectin alongside hormone therapy; says PSA is holding at 0.01. HealthUnlocked, 2021-08 (PSA was measured while on hormone therapy, which alone can explain it.)
- Helped Took fenbendazole and ivermectin about 1 mg/kg daily; says PSA did not rise for 8 months and fell for the first time. HealthUnlocked, 2025-06 (Started before radiotherapy, but the timeline against other treatment is unclear.)
- Mixed Took both for several months; PSA stopped rising in the first month only, then kept progressing. HealthUnlocked, 2025-06 (Says it may not suit stage 4 disease; no numbers given.)
- Helped Took both for six months and says PSA fell, with no side effects or changes in his liver tests. HealthUnlocked, 2025-06 (Also on relugolix and radiotherapy, which lower PSA on their own.)
- Helped Takes 4-day cycles of 12 mg ivermectin and fenbendazole each month and credits them with keeping his CEA marker near undetectable after colon surgery. HealthUnlocked, 2025-06 (Marker after surgery that removed the tumor; does not think they help his prostate cancer.)
- Mixed PSA fell from 13.36 to 12.22 on high-dose ivermectin, fenbendazole, keto and fasting; elsewhere he says it later reversed and he began hormone therapy. HealthUnlocked, 2025-01 (Small PSA change; switched to standard treatment.)
- Helped Wife reports his urinary symptoms disappeared within two weeks and PSA fell from 4.7 to 3.7 between February and April. HealthUnlocked, 2025-04 (Caregiver report; surgery and hormone therapy had been recommended, unclear what he received.)
- Mixed After triplet therapy he stopped hormone drugs for 12 to 36 mg ivermectin daily; a PSMA scan was clear, PSA rose slightly. HealthUnlocked, 2025-06 (Caregiver report; the clear scan followed standard triplet therapy.)
- Too early Taking fenbendazole and ivermectin and waiting for his next PSA test to see whether they work. HealthUnlocked, 2025-06 (No result yet.)
- Too early Takes horse-paste ivermectin about three days a week; PSA hit a new low but he is also on hormone therapy and draws no conclusion. HealthUnlocked, 2021-06 (Says elsewhere he has used it only alongside standard treatment.)
- Helped Taking 18 to 30 mg of liquid ivermectin weekly for over a year; PSA has stayed at 0.02 for six months off hormone therapy. HealthUnlocked, 2024-08 (He says he does not know whether ivermectin is the reason.)
- Helped Says PSA fell from 6 to 0.9 off hormone therapy and 0.75 to 0.11 on it, taking 48 mg every other day for 12 days. HealthUnlocked, 2022-06 (Short course; part of the fall was on hormone therapy.)
- Helped Off hormone therapy, PSA had reached 2,658; within three months of ivermectin and fenbendazole it fell to 164, rose when he lapsed, then fell again. HealthUnlocked, 2026-07 (No medical follow-up or scans; very large PSA swings.)
- Helped Takes ivermectin with other repurposed drugs; says PSA has stayed around 4 to 5 and MRI lesions stopped growing. HealthUnlocked, 2025-01 (Low-risk disease under surveillance; several drugs at once.)
- Too early Two months into an ivermectin protocol and waiting for scans and blood work. HealthUnlocked, 2025-06 (No result yet.)
- Too early Took prescribed ivermectin for three days for COVID-19; lymphocyte count went from about 30,000 to 26,500, which he thought might be coincidence. HealthUnlocked, 2021-05 (A forum administrator notes a drop this size is common in CLL.)
- Mixed Weekly ivermectin from mid-2021; lymphocyte counts that had been doubling leveled off near 27,000, but his haematologist later started treatment anyway. HealthUnlocked, 2022-02 (Not taken for cancer; standard treatment followed.)
Checked against PubMed on 2026-10-28.