Study Finds Ivermectin and Mebendazole Beneficial in Treating Cancer

A new peer-reviewed study on ivermectin and mebendazole as a cancer treatment has been published in the international oncology journal Anticancer Research. The study found that 84.4 percent of cancer patients taking ivermectin and mebendazole for six months reported cancer disappearance, tumor regression, or cancer stabilization.¹

Described by its authors as the largest real-world human study of its kind, the research marks the first time a prospective observational cohort of cancer patients, who were prescribed the ivermectin-mebendazole combination, has been evaluated and results published in a major peer reviewed oncology journal. Until now, evidence supporting ivermectin as a cancer treatment had been limited to laboratory models and animal studies.

Nicolas Hulscher, MPH, epidemiologist and corresponding author of the study, said in a Substack post discussing findings that the study “represents one of the most compelling clinical signals ever documented for repurposed anti-parasitic therapies in oncology.” Evaluating the study findings, Hulscher says, “At approximately six months post-treatment initiation, we observed an 84.4% Clinical Benefit Ratio (CBR)—meaning more than four out of five patients reported either no evidence of disease (remission), tumor regression, or cancer stabilization.”²

A CBR is a metric used primarily in cancer trials. It measures the percentage of patients whose tumors shrink completely, partially, or remained stable for at least six months. In short, CBR identifies how many patients benefit from a cancer treatment. The recently published study defined CBR as “a priori as the proportion of participants with NED, regression, or stable disease.”³

Study Results “Striking,” Researchers Note Clinical Importance of Ivermectin-Mebendazole Combination

The study authors further stated:

The exceptionally high, self-reported CBR of 84.4% observed at the 6-month follow-up in this diverse real-world cohort is striking and underscores the potential clinical importance of the ivermectin and mebendazole combination. This level of disease control (no evidence of disease, regression, or stability) substantially exceeds typical clinical benefit and disease control rates reported with standard chemotherapy in advanced or pretreated solid tumors.¹

The reported benefits of the Ivermectin-Mebendazole protocol extended to metastatic prostate and breast cancers. The study noted:

In metastatic castration-resistant prostate cancer, the most represented malignancy in our cohort, metronomic chemotherapy regimens have demonstrated mean clinical benefit fractions of approximately 56.8%.¹

Similarly, in metastatic breast cancer, conventional chemotherapy typically achieves clinical benefit fraction of 50-60% in the first-line setting, with notably lower proportions in subsequent lines or heavily pretreated patients. Disease control percents with later-line chemotherapy in non-small cell lung cancer and colorectal cancer are frequently below 60%.¹

How Ivermectin and Mebendazole Work

Ivermectin is an FDA-approved anti-parasitic medication that has demonstrated multi-target anticancer activity in preclinical models, inhibiting cancer cell proliferation, blocking key tumor growth pathways, and selectively targeting cancer stem cells. Mebendazole is also an anti-parasitic, but attacks cancer from a different angle, primarily by disrupting microtubules, a kind of structural scaffolding cancer cells rely on to divide. Where ivermectin targets the signaling, mebendazole targets the structure.¹

As the study authors stated:

When used together, these agents [ivermectin and mebendazole] target non-overlapping pathways, resulting in synergistic tumor regression, cancer stem cell depletion, and reversal of multidrug resistance in multiple in vitro and in vivo models.¹

The drugs, when used together, demonstrated clinical benefit across a heterogeneous, real-world cancer population, including patients with prostate, breast, lung, colon, liver, and other malignancies, many of whom were also receiving conventional therapies such as chemotherapy, radiation, and surgery.¹

NCI Preclinical Study and Growing Public Interest

The study was published amid growing public interest in ivermectin as a potential cancer treatment. In February 2026, the National Cancer Institute (NCI) announced plans  to conduct a preclinical study on the use of ivermectin as a potential cancer treatment, a plan driven by growing public interest that drew criticism from some scientists and doctors who believed there was insufficient available data to support the investigation and that studying it would be a waste of resources, despite a growing body of laboratory and animal research suggesting potential anticancer effects of the drug.^{4 5}

The NCI’s announced study remains preclinical, meaning it has not yet advanced to human trials. The Hulscher study, by contrast, evaluated real-world outcomes in 197 human cancer patients over six months.⁵

Critics of studying ivermectin for potential anticancer benefits expressed similar sentiments toward patients who used ivermectin as an off-label treatment for SARS-CoV-2 infection, despite a 2021 randomized trial published in the Journal of Medical Virology which reported that ivermectin was associated with reduced symptoms among household contacts of COVID-19 cases. As the trial reported, “There was a statistically significant reduction in the development of symptoms among contacts who received ivermectin compared to those who did not.”⁴

Hulscher said:

What makes these findings especially notable is that this was a heterogeneous, real-world cancer population—including patients with prostate, breast, lung, colon, liver, and many other malignancies, many of whom were also undergoing conventional therapies such as chemotherapy, radiation, and surgery. With these extraordinarily promising results, double-blind, placebo-controlled clinical trials are now required. In the meantime, many cancer patients are exercising their right to try.²

If you would like to receive an e-mail notice of the most recent articles published in The Vaccine Reaction each week, click here.