Ivermectin and Mebendazole in Cancer: Inside the First Real-World Cohort.

In April 2026, the peer-reviewed journal Anticancer Research accepted a study that drug-repurposing circles had been waiting on for months. Titled "Real-world Clinical Outcomes of Ivermectin and Mebendazole in Cancer Patients," it is the largest structured evaluation of this specific two-drug combination published to date: 197 cancer patients prescribed compounded ivermectin and mebendazole through a U.S. telemedicine platform, surveyed at baseline and again roughly six months later.

The author list is notable. It includes epidemiologist Nicolas Hulscher and cardiologist Peter McCullough of the McCullough Foundation, physicians affiliated with The Wellness Company, and Harvey Risch, professor emeritus of epidemiology at the Yale School of Public Health. It is also, as we will get to, the study's single most important disclosure.

What the study did

Participants were adults with confirmed cancer diagnoses who received off-label prescriptions for compounded capsules containing 25 mg of ivermectin and 250 mg of mebendazole, typically 90 capsules to start, with dosing individualized between one and four capsules per day. The baseline survey ran from August to September 2025. Follow-up came between January and March 2026. Of the 197 who enrolled, 122 (61.9%) completed it.

The cohort skewed older, with a mean age of 67, and was split nearly evenly by sex. Prostate cancer (27.9%) and breast cancer (18.3%) were the most common diagnoses, followed by lung, colon, liver, and a long tail of other malignancies. At baseline, 37.1% said their cancer was actively spreading or progressing. The remaining 62.9% described it as stable or not currently spreading.

What it found

The headline number is the Clinical Benefit Ratio: 84.4% of the 122 follow-up participants (95% confidence interval, 77.0 to 89.8%) reported no current evidence of disease, tumor regression, or stable disease at six months. Broken out, 32.8% reported no current evidence of disease, 15.6% reported regression, 36.1% reported stable disease, and 15.6% reported progression.

Adherence was high for a self-directed oral protocol. 86.9% completed the initial 90-capsule prescription, and 66.4% were still taking the combination at follow-up. Side effects were reported by 25.4%, predominantly mild and gastrointestinal. Of those who had them, 93.6% continued therapy after minor adjustments, and only two participants discontinued outright. An exploratory dose-response analysis found no relationship between daily capsule count and cancer outcomes (p=0.91), with the benefit ratio holding between 81.5% and 91.2% across all four dosing tiers.

The authors contextualize the 84.4% figure against clinical benefit rates typically reported with chemotherapy in advanced disease: roughly 56.8% with metronomic regimens in metastatic castration-resistant prostate cancer, and 50 to 60% for first-line chemotherapy in metastatic breast cancer, with lower figures in later treatment lines.

Why researchers take this combination seriously

The pairing is not arbitrary. In preclinical work, ivermectin has shown activity against more than a dozen cancer types through multiple mechanisms at once: inhibition of PAK1 kinase, disruption of Wnt/beta-catenin, PI3K/Akt/mTOR, and STAT3 signaling, induction of mitochondrial dysfunction, and selective targeting of cancer stem cells, the subpopulation blamed for recurrence and drug resistance. Mebendazole works differently. It destabilizes microtubules, the same structural target exploited by taxane chemotherapies, driving cell-cycle arrest and apoptosis while inhibiting the blood vessel growth tumors depend on. Because the two drugs hit non-overlapping pathways, laboratory models have reported synergy when they are combined.

There are earlier human signals too. A small randomized trial in metastatic colorectal cancer found that adding mebendazole to bevacizumab plus FOLFOX4 chemotherapy raised the objective response rate from 10% to 65% and roughly tripled median progression-free survival. And an early-phase trial pairing ivermectin with the immunotherapy balstilimab reported acceptable tolerability in heavily pretreated breast cancer patients.

The fine print, which matters as much as the numbers

Every outcome in this study is self-reported. No scans, pathology reports, or medical records were reviewed. "No evidence of disease" here means a patient checked that box on a survey, not that an oncologist confirmed it. There was no control group, and 38% of the original cohort never completed follow-up.

Confounding is everywhere. At follow-up, 27.9% of participants were on concurrent chemotherapy, 21.3% had radiation, 19.7% had surgery, 49.2% took other cancer-related supplements, and 37.7% made dietary changes. Attributing anyone's outcome to the capsules is impossible on this design. And because nearly two-thirds of the cohort entered the study with disease they described as not currently spreading, a large share was predisposed to look stable six months later regardless of what they took.

To the authors' credit, they checked whether survey completers were simply the healthier patients, and found chemotherapy and radiation use statistically comparable between the follow-up group and the full baseline cohort. They are also blunt about the ceiling of their own data: "therapeutic benefit cannot be inferred," the paper states, framing the results as hypothesis-generating and calling for randomized, double-blind, placebo-controlled trials.

Then there is the conflict of interest, disclosed plainly in the paper: every author is affiliated with or receives salary support from The Wellness Company, which operates the telemedicine platform that prescribed the formulation and sells compounded ivermectin-mebendazole as part of its clinical services. That does not invalidate the data. It does mean independent replication matters here more than usual.

Why this research persists anyway

Both drugs have decades of human safety data and cost very little. The paper estimates a daily ivermectin-mebendazole regimen at roughly $2,000 to $3,000 per year, against an average annual cost of standard chemotherapy around $111,000. That same off-patent economics is why the evidence keeps arriving in exactly this form, observational cohorts and small investigator-led trials, rather than the large industry-funded studies that settle questions: no sponsor stands to recoup the cost of running one.

The bottom line

This is a real, structured, peer-reviewed signal, and the honest reading is that it justifies exactly what its authors ask for: proper randomized trials. It is not proof, and it is not a treatment. Ivermectin and mebendazole are FDA-approved medicines for parasitic infections. No compounded combination of them is approved to treat cancer, and this study does not change that. Anyone living with a cancer diagnosis who is curious about adjunctive approaches should bring the question to their oncologist rather than around them. On that point, the study's authors and mainstream oncology are in full agreement.

CLYR Health offers ivermectin and mebendazole only as licensed-provider antiparasitic protocols after medical intake. We do not market them as cancer treatments, and this article is not a treatment recommendation. It is coverage of published research.