# Ivermectin

Source: https://onco.cc/drugs/ivermectin/  
OnCo record `ivermectin` (Treatment). Data CC BY-NC 4.0, attribute "Data from OnCo (onco.cc)"; commercial use needs a licence.

## TL;DR

Ivermectin is a worm and parasite medicine that is being tested as an add-on to immunotherapy in two small early trials. No trial has shown that it treats any cancer, and people who have dosed themselves outside a trial have ended up in hospital with seizures or liver damage.

## Summary

Ivermectin is approved in the United States as Stromectol for intestinal strongyloidiasis and onchocerciasis, two parasitic worm infections, and for nothing else (Stromectol label on DailyMed). The approval dates from 22 November 1996 under NDA 050742 (Drugs@FDA NDA 050742). The World Health Organization lists it as an essential medicine for onchocerciasis, strongyloidiasis, other soil-transmitted worm infections and scabies (WHO Model List of Essential Medicines).

Reviews collect cell-culture and mouse experiments in which ivermectin slowed cancer cells or shrank tumours in animals through several pathways at once, and note that no large randomised trial has confirmed any benefit in people (Patel review 2025). The most cited animal experiment reported that ivermectin plus an anti-PD-1 antibody limited tumour growth in mouse models of breast cancer where neither agent alone worked (Draganov mouse study 2021). That paper now carries an editorial expression of concern because several images in one figure were found to be duplicates and the authors said the original data were no longer available (Expression of concern 2026).

All 239 ivermectin studies registered on ClinicalTrials.gov were screened for this page, and two are cancer treatment trials: a phase 1/2 study at Cedars-Sinai giving ivermectin with balstilimab or pembrolizumab to about 34 patients with metastatic triple-negative breast cancer, recruiting since October 2023 with no results posted (ClinicalTrials.gov NCT05318469), and ICONIC, a University of Florida phase 2 comparing two ivermectin doses alongside a standard checkpoint inhibitor in 80 patients with solid tumours, not yet recruiting and measuring a change in immune cells rather than tumour response (ClinicalTrials.gov NCT07487805). The ICONIC registry entry says that among the first nine patients treated in the Cedars-Sinai study no treatment-related serious adverse events were observed, which is the only human safety information from either trial so far (ClinicalTrials.gov NCT07487805). Two other registered studies are not tests of ivermectin against cancer: a São Paulo phase 2 of ivermectin plus losartan for COVID-19 in cancer patients, stopped for futility after 77 of a planned 176 patients (ClinicalTrials.gov NCT04447235), and a Mexican clinic's 'atavistic chemotherapy' protocol that lists ivermectin among eight antiprotozoal drugs, last updated in 2022 with no results (ClinicalTrials.gov NCT02366884). No phase 3 trial exists, and neither cancer trial has reported whether ivermectin shrinks tumours or lengthens life (ClinicalTrials.gov NCT05318469).

Outside trials the human evidence is survey and anecdote: 19 percent of cancer patients interviewed in Loja, Ecuador said they took ivermectin alongside chemotherapy, radiotherapy or immunotherapy (Loja survey 2023). A telemedicine cohort of 197 patients prescribed ivermectin with mebendazole reported self-assessed benefit in 84 percent of the 122 who answered a six-month survey (Hulscher cohort 2026). The journal has placed an expression of concern on that paper while it audits ethical approval and whether the diagnoses and reported regressions can be verified (Anticancer Research expression of concern 2026). A review for gynaecological cancers finds the clinical data limited to cell lines and 'strongly cautions' against use (Mujumdar review 2025), and the accompanying editorial notes that no major oncology organisation, including ASCO, SGO or NCCN, endorses ivermectin for cancer (Straughn editorial 2025).

Harm from self-dosing is documented: a 73-year-old woman with metastatic breast cancer who took high doses on the strength of online information developed seizures and respiratory failure and needed a ventilator, recovering within 48 hours (Saperstein case report 2026). A 65-year-old man with prostate cancer who alternated veterinary fenbendazole and ivermectin for three months developed severe liver injury that resolved within six weeks of stopping (Powderly case report 2026). An Oregon poison-centre series of 37 people who took ivermectin against COVID-19, most men over 60, recorded neurotoxicity in 30, hospital admission in 21 and one death (Hoang poison centre series 2022). The label itself records drowsiness, stupor, coma, confusion and death at recommended doses and in overdose, most often after veterinary products (Stromectol label on DailyMed). After a January 2025 podcast, combined ivermectin and benzimidazole prescribing to US cancer patients ran 2.6 times higher than in the same months a year earlier (Rockwell JAMA Network Open 2026).

The bottom line for a patient who has read about this drug online: it is being studied in two early trials, no trial has shown that it treats any cancer, and dosing outside a trial has caused documented harm (Stromectol label on DailyMed). The one trial open to patients is the Cedars-Sinai study in metastatic triple-negative breast cancer (ClinicalTrials.gov NCT05318469). The FDA's guidance on products promoted as cancer cures without trial evidence applies here (FDA on products claiming to cure cancer).

## Fields

- Kind: Treatment
- Status: phase-2
- Last checked: 2026-09-24
- Also known as: Stromectol; IVM; MK-0933
- Brand: Stromectol
- Modality: Oral antiparasitic small molecule (macrocyclic lactone), studied in cancer as an add-on to checkpoint antibodies
- Mechanism: In parasites ivermectin opens glutamate-gated chloride channels and paralyses the worm. In cancer cell lines and mice it has been reported to act on several things at once, including the ATP-gated P2X4 and P2X7 receptors, WNT-TCF and Akt/mTOR signalling and PAK1, and the trials pair it with an anti-PD-1 antibody on the mouse finding that the pair drew T cells into tumours where neither drug alone worked. All of this is laboratory evidence; none of it has been shown in a patient.
- Dosing: Oral tablet, 3 mg (Stromectol); Label: a single dose of about 200 micrograms per kg for strongyloidiasis and about 150 micrograms per kg for onchocerciasis, taken on an empty stomach with water; no cancer dose exists. Trials: the Cedars-Sinai study gives an assigned dose on days 1 to 3 of each week of a 21-day cycle with the antibody, and ICONIC compares 200 and 400 micrograms per kg on days 1 to 3 weekly for four weeks.

## Notes

- Being studied: two early trials, one recruiting in metastatic triple-negative breast cancer (ClinicalTrials.gov NCT05318469) and one not yet open, ICONIC, which measures an immune-cell change rather than tumour shrinkage (ClinicalTrials.gov NCT07487805).
- Not shown to treat any cancer: neither trial has reported a result and no phase 3 exists (ClinicalTrials.gov NCT05318469). The only published human data are a survey (Loja survey 2023) and a self-reported cohort under an expression of concern (Anticancer Research expression of concern 2026).
- Harm outside trials: seizures and mechanical ventilation after high-dose self-use (Saperstein case report 2026), severe liver injury with veterinary fenbendazole (Powderly case report 2026), a poison-centre series with one death (Hoang poison centre series 2022), and the label's own warning of coma and death with overdose (Stromectol label on DailyMed).
- Tell your oncologist if you are taking it: the toxicity review names P-glycoprotein, the pump that keeps ivermectin out of the brain, as the central factor in neurotoxicity, so anything that blocks it raises the risk (Yilmaz toxicity review 2026). A paediatric case of severe neurotoxicity in a patient on regorafenib was attributed to a CYP3A4 interaction (ClinicalTrials.gov NCT07487805).

## Sources

- Wikipedia: https://en.wikipedia.org/wiki/Ivermectin
- Stromectol label on DailyMed: https://dailymed.nlm.nih.gov/dailymed/drugInfo.cfm?setid=681888c9-af79-4b7d-ae80-c3f4f6f1effd
- Drugs@FDA NDA 050742: https://www.accessdata.fda.gov/scripts/cder/daf/index.cfm?event=overview.process&ApplNo=050742
- WHO Model List of Essential Medicines: https://list.essentialmeds.org/medicines/58
- ClinicalTrials.gov NCT05318469: https://clinicaltrials.gov/study/NCT05318469
- ClinicalTrials.gov NCT07487805: https://clinicaltrials.gov/study/NCT07487805
- ClinicalTrials.gov NCT04447235: https://clinicaltrials.gov/study/NCT04447235
- ClinicalTrials.gov NCT02366884: https://clinicaltrials.gov/study/NCT02366884
- FDA on products claiming to cure cancer: https://www.fda.gov/consumers/consumer-updates/products-claiming-cure-cancer-are-cruel-deception
- Patel review 2025: https://doi.org/10.1007/s11912-025-01704-z
- Draganov mouse study 2021: https://doi.org/10.1038/s41523-021-00229-5
- Expression of concern 2026: https://doi.org/10.1038/s41523-026-00988-z
- Loja survey 2023: https://doi.org/10.3390/nursrep13010030
- Hulscher cohort 2026: https://doi.org/10.21873/anticanres.18194
- Anticancer Research expression of concern 2026: https://doi.org/10.21873/anticanres.18276
- Mujumdar review 2025: https://doi.org/10.1016/j.gore.2025.101803
- Straughn editorial 2025: https://doi.org/10.1016/j.gore.2025.101920
- Saperstein case report 2026: https://doi.org/10.1080/00325481.2026.2672183
- Powderly case report 2026: https://doi.org/10.7759/cureus.108896
- Hoang poison centre series 2022: https://doi.org/10.1080/15563650.2022.2134788
- Rockwell JAMA Network Open 2026: https://doi.org/10.1001/jamanetworkopen.2026.16780
- Yilmaz toxicity review 2026: https://doi.org/10.1002/jat.70166
- Wikipedia: https://en.wikipedia.org/wiki/Ivermectin

## Connected records

- cancers: [Triple-negative breast cancer (TNBC)](https://onco.cc/cancers/tnbc/)
- technologies: [Fenbendazole, ivermectin and other internet 'repurposed cures'](https://onco.cc/technologies/fenbendazole-ivermectin-repurposing-claims/), [Immune checkpoint inhibitors](https://onco.cc/technologies/checkpoint-inhibitor/), [Systematic drug repurposing](https://onco.cc/technologies/drug-repurposing/)
- drugs: [Balstilimab](https://onco.cc/drugs/balstilimab/), [Fenbendazole (veterinary anthelmintic)](https://onco.cc/drugs/fenbendazole/), [Mebendazole](https://onco.cc/drugs/mebendazole/), [Pembrolizumab](https://onco.cc/drugs/pembrolizumab/)
- companies: [Agenus](https://onco.cc/companies/agenus/), [Merck & Co. (MSD)](https://onco.cc/companies/merck/)
- institutions: [Cedars-Sinai Cancer](https://onco.cc/institutions/cedars-sinai-cancer/), [University of Florida Health Cancer Center](https://onco.cc/institutions/uf-health-cancer-center/)
- terms: [Cell line](https://onco.cc/terms/cell-line/), [Hepatotoxicity (liver enzyme elevation)](https://onco.cc/terms/hepatotoxicity/), [In vitro and in vivo](https://onco.cc/terms/in-vitro-in-vivo/), [Objective response rate (ORR)](https://onco.cc/terms/orr/), [Off-label](https://onco.cc/terms/off-label/), [Pharmacokinetics (PK), half-life and exposure](https://onco.cc/terms/pharmacokinetics/), [Phase 1, 2 and 3 trials](https://onco.cc/terms/trial-phases/), [Preclinical](https://onco.cc/terms/preclinical/), [Recommended phase 2 dose (RP2D)](https://onco.cc/terms/rp2d/), [Single-arm trial](https://onco.cc/terms/single-arm/)
- trials: [Atavistic chemotherapy: combinations of antibacterial, antifungal and antiprotozoal drugs in advanced cancer (Arguello clinic, status unknown)](https://onco.cc/trials/nct02366884/), [ICONIC: ivermectin combined with immune checkpoint inhibition in cancer (University of Florida phase 2)](https://onco.cc/trials/nct07487805/), [Ivermectin plus losartan for COVID-19 in cancer patients (ICESP phase 2, terminated)](https://onco.cc/trials/nct04447235/), [Ivermectin with balstilimab or pembrolizumab in metastatic triple-negative breast cancer (Cedars-Sinai phase 1/2)](https://onco.cc/trials/nct05318469/)
- bottlenecks: [Misinformation and unproven therapies](https://onco.cc/bottlenecks/b-misinformation/), [No incentive to repurpose cheap drugs](https://onco.cc/bottlenecks/b-generic-repurposing/)
- key papers: [Cancer therapy using antiparasitic medications guided by acupuncture meridian assessment: a case series of six patients](https://onco.cc/key-papers/paper-guilford-antiparasitic-acupuncture-meridian-case-series-2026/), [Characteristics of ivermectin toxicity in patients taking veterinary and human formulations for the prevention and treatment of COVID-19](https://onco.cc/key-papers/paper-hoang-ivermectin-toxicity-clin-toxicol-2022/), [Drug-induced liver injury following co-ingestion of veterinary fenbendazole and ivermectin for prostate cancer: a case report](https://onco.cc/key-papers/paper-powderly-fenbendazole-ivermectin-liver-injury-2026/), [Exposures to bleach, peroxide, disinfectants, antimalarials, and ivermectin reported to the California Poison Control System before and during the COVID-19 pandemic, 2015 to 2021](https://onco.cc/key-papers/paper-ghai-california-poison-control-ivermectin-2024/), [Ivermectin and gynecologic cancer: what's the data?](https://onco.cc/key-papers/paper-mujumdar-ivermectin-gynaecological-cancer-2025/), [Ivermectin converts cold tumors hot and synergizes with immune checkpoint blockade for treatment of breast cancer (with 2026 expression of concern)](https://onco.cc/key-papers/paper-draganov-ivermectin-cold-tumours-npj-breast-cancer-2021/), [Ivermectin in cancer treatment: should healthcare providers caution or explore its therapeutic potential?](https://onco.cc/key-papers/paper-patel-ivermectin-cancer-curr-oncol-rep-2025/), [Ivermectin toxicity in humans and animals: clinical spectrum, mechanisms, and management](https://onco.cc/key-papers/paper-yilmaz-ivermectin-toxicity-j-appl-toxicol-2026/), [Ivermectin treatment for gynecologic cancers: hope versus hype](https://onco.cc/key-papers/paper-straughn-ivermectin-hope-versus-hype-2025/), [Ivermectin-benzimidazole prescribing following celebrity endorsement](https://onco.cc/key-papers/paper-rockwell-ivermectin-benzimidazole-prescribing-jama-netw-open-2026/), [Ivermectin, a potential anticancer drug derived from an antiparasitic drug](https://onco.cc/key-papers/paper-tang-ivermectin-potential-anticancer-pharmacol-res-2021/), [Life-threatening neurotoxicity following off-label ivermectin use in metastatic breast cancer: a case report](https://onco.cc/key-papers/paper-saperstein-ivermectin-neurotoxicity-breast-cancer-2026/), [Metastatic melanoma with initial ctDNA decline and radiographic response during self-directed antiparasitic use: treatment effect or spontaneous regression?](https://onco.cc/key-papers/paper-cheng-melanoma-ctdna-antiparasitic-front-oncol-2026/), [Outcome of ivermectin in cancer treatment: an experience in Loja, Ecuador](https://onco.cc/key-papers/paper-jimenez-gaona-ivermectin-loja-ecuador-2023/), [Real-world clinical outcomes of ivermectin and mebendazole in cancer patients: results from a prospective observational cohort (with 2026 expression of concern)](https://onco.cc/key-papers/paper-hulscher-ivermectin-mebendazole-cohort-anticancer-res-2026/), [Synergistic anti-tumor effect of dichloroacetate and ivermectin](https://onco.cc/key-papers/paper-ishiguro-dichloroacetate-ivermectin-cureus-2022/), [The multitargeted drug ivermectin: from an antiparasitic agent to a repositioned cancer drug](https://onco.cc/key-papers/paper-juarez-ivermectin-repositioned-cancer-drug-2018/), [The threat of medical misinformation: a case of ivermectin toxicity in a pediatric oncology patient](https://onco.cc/key-papers/paper-gilene-ivermectin-toxicity-paediatric-oncology-2025/)

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