Home › Answers › Ivermectin

Does ivermectin work against cancer?

By the Cancer Clues team · Last updated 1 November 2026 · How our grades work

Here because of a specific diagnosis? This topic appears in our guides to: Breast Cancer

What it is

Ivermectin is an anti-parasitic drug so useful against river blindness and other parasitic diseases that its discoverers won the Nobel Prize. In recent years it became an internet phenomenon first for COVID, then for cancer — boosted in January 2025 by a celebrity podcast, after which prescriptions among cancer patients measurably surged [8].

What the evidence says

• Lab and mouse studies show ivermectin can kill cancer cells and may nudge the immune system against tumors [6]. Notably, a key mouse study that motivated the human trial is now under a formal editorial integrity notice for duplicated images — “interpret with caution”, says the journal [7].
• One human trial exists — small and still running: ivermectin plus an immunotherapy drug (balstilimab) in metastatic triple-negative breast cancer at a major U.S. cancer center. Its 2025 interim report covered safety only, in nine patients; among those evaluable, most progressed. The trial is ongoing, with no efficacy results posted as of 1 November 2026 [1][2].
• The professional verdict: the American Society of Clinical Oncology formally recommends against ivermectin for cancer outside clinical trials [3]; the American Cancer Society and Macmillan (UK) concur that no clinical evidence supports it [4][5].

What patients report

As with fenbendazole, there are many passionate stories online, almost always alongside conventional treatment — which makes them uninterpretable as evidence, in either direction. The honest status is simpler: the question is being tested properly for the first time right now, and until that trial reads out, nobody — including the loudest voices online — knows the answer. Real-world experience to share? .

Safety and interactions

• At approved anti-parasite doses, human-formulation ivermectin is generally safe. The “cancer protocols” circulating online use chronic, higher dosing with no safety data at all.
• Animal formulations are the real danger: concentrated for livestock and containing ingredients never tested in humans — the FDA has documented serious poisonings [9].
• A severe liver injury is published in a cancer patient self-treating with ivermectin plus fenbendazole [see our fenbendazole page].
• Ivermectin interacts with the same liver pathways as many cancer drugs; those interactions are simply unstudied. Tell your team if you take it.

If you're considering it anyway

Use only human formulations, prescribed by a doctor who knows your full drug list. Never let it delay or replace actual treatment. And watch the real trial: it is listed publicly [2], and its results — positive or negative — will be the first genuine answer. We will update this page the week they publish, whichever way it goes. That's a promise.

Common questions