Ivermectin
Also called: Stromectol.
Last reviewed 2026-09-16. How this works.
Treating cancer Grade D
No human evidence of benefit, or none that survived testing.
Trials of this drug in cancer are under way, but none has reported a result yet.
Trials are registered and recruiting. None has reported.
The claim
Ivermectin is an antiparasitic drug licensed for human use. The claim is that it also works against cancer, often repeated alongside fenbendazole.
What it does
Laboratory work has proposed several ways it might act on cancer cells. The chapter notes carry no human measurement of any of them, so the register records the proposals as proposals.
The evidence
This is the one entry in the chapter where something is actually under way. A phase I/II trial is combining ivermectin with immunotherapy in metastatic triple-negative breast cancer, and preliminary observations from the first nine people enrolled were presented at a conference. A randomised phase II trial, ICONIC, is registered to combine it with checkpoint inhibitors in solid tumours.1
Neither has reported a result. A registered trial is a question being asked, not an answer, and a conference presentation of the first nine people enrolled is not a finding.1
The American Society of Clinical Oncology states that no robust, peer-reviewed clinical evidence demonstrates that ivermectin is effective for treating any human cancer, and recommends against its use outside a trial.2
The studies this rests on
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ICONIC, ivermectin with checkpoint inhibitors in solid tumours (NCT07487805)1
A randomised trial, phase 2, measured a clinical outcome, 80 participants.
registered, not yet reported. A registered trial is a question, not an answer.
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Ivermectin with balstilimab or pembrolizumab in metastatic triple-negative breast cancer1
A trial with no comparison group, open label, phase 1, measured safety, 9 participants.
preliminary observations from the first nine people enrolled, presented at a conference; not reported as a result. Nothing has been reported from it.
The harm
What has not been looked at
The safety of ivermectin in someone receiving cancer treatment has not been established. Its safety record in its licensed use is a different question, in different people, at different amounts.
Scope: people with cancer.
Established by regulatory statement, ASCO Clinical Notice, May 2026, checked 2026-05-01. Result: the notice cites the potential for toxicity and for harmful drug interactions.2
What is absent
No trial of ivermectin in cancer has reported a result. Two are under way, which is different from two having answered anything.
Scope: any tumour type, any endpoint.
Established by regulatory statement, ASCO Clinical Notice, May 2026, checked 2026-05-01. Result: no robust, peer-reviewed clinical evidence for treating any human malignancy.21
What to ask
Is there an open trial of ivermectin I could be considered for?
The dish-to-person gap
The register records no human pharmacokinetic measurement for ivermectin in a cancer setting. Human pharmacokinetic data exists for its licensed use, but the chapter notes carry no figure, so none is recorded.
When to call your team — no warning signs are recorded
Whatever you are taking or thinking of taking, the people treating you can only weigh it if they know about it. That is true when nothing has been written down here, and it is most true then.
The register records no warning signs for this entry, because the sources here describe a potential for toxicity rather than a documented injury in a person taking it for cancer. That is not a statement that nothing can go wrong.
Interactions
Ivermectin is metabolised through the cytochrome P450 pathway in the liver, and a professional body states that its use may alter how established cancer therapies behave in the body. The mechanism is named; the size of the effect has not been measured in anyone taking it for cancer.2
Ivermectin
Recorded as documented, and the source names no particular treatment.
Does ivermectin going through the same liver enzymes as some cancer drugs matter for what I am on?
The whole interaction list, and how to turn it into a pharmacy review request.
Find a trial instead
Unlike most entries in this chapter, there is something to find: two studies are under way, and one is recruiting.
Search ClinicalTrials.gov for recruiting studies of ivermectin
A trial is the same decision with monitoring, a known preparation and a doctor who knows what else you are taking.
References
Two in-progress ivermectin oncology studies identified in the ASCO Clinical Notice of May 2026, including ICONIC, ClinicalTrials.gov NCT07487805.
How this was reached: transcribed from chapter note, via docs/CHAPTER-NOTES.json, chapter 13 note 4.
ASCO Clinical Notice, May 2026, recommending against ivermectin and fenbendazole for cancer treatment outside of clinical trials. Published by the American Society of Clinical Oncology.
https://connection.asco.org/do/asco-clinical-notice-recom…
How this was reached: transcribed from chapter note, via docs/CHAPTER-NOTES.json, chapter 13 note 6.