A summary of the 2026 prospective observational cohort study on ivermectin and mebendazole in cancer patients — the largest real-world analysis published to date. Sources linked so you can read the primary literature yourself. This page will be updated as additional studies are published.
Background: Why Researchers Are Looking at Ivermectin and Mebendazole
Ivermectin is an antiparasitic drug whose discoverers shared the 2015 Nobel Prize in Physiology or Medicine. It was originally used to treat onchocerciasis and other parasitic infections. Over the last decade, laboratory and animal studies have identified multiple anticancer mechanisms: disruption of cancer stem cells, inhibition of Wnt/β-catenin and PAK1 signaling, interference with mitochondrial oxidative phosphorylation, and modulation of autophagy.
Mebendazole is an antiparasitic from the benzimidazole family. It binds tubulin and disrupts microtubule assembly — the same mechanism used by some chemotherapy drugs (e.g., vincristine, paclitaxel). Benzimidazoles have also been reported to inhibit glucose uptake in rapidly dividing cells, which is relevant because many cancers depend heavily on glucose metabolism (the Warburg effect).
Until recently, the human clinical evidence for both drugs in oncology has been limited to case reports, small case series, and laboratory work. The 2026 study below is the largest real-world human cohort published so far.
The 2026 Hulscher / McCullough Foundation Study
Nicholas Hulscher (McCullough Foundation) and colleagues published “Real-World Clinical Outcomes of Ivermectin and Mebendazole in Cancer Patients: Results from a Prospective Observational Cohort” on April 7, 2026 (preprint, Zenodo). The study analyzed 197 cancer patients who were prescribed ivermectin and mebendazole off-label through a licensed U.S. telemedicine platform.
Protocol
- Compounded oral capsules containing 25 mg ivermectin + 250 mg mebendazole
- Prescribed off-label by licensed U.S. healthcare providers via telemedicine
- Outcomes reported at 6 months
- Outcomes were patient-reported (including clinician-documented imaging/pathology where available)
Results
- Clinical Benefit Ratio (CBR): 84.4% (95% CI: 77.0–89.8%) — meaning 84.4% of participants reported regression, no current evidence of disease, or stabilization.
- 48.4% reported the strongest positive outcomes (95% CI: 39.7–57.1%), broken down as:
- 32.8% — no current evidence of disease (NED)
- 15.6% — regression
- 36.0% — stable disease
- 15.6% — did not meet the clinical benefit threshold (progression or insufficient response)
Direct quote from the study authors: “Given the observational design, reliance on self-reported outcomes, and potential for selection bias and uncontrolled confounding, these findings should be interpreted as hypothesis-generating. Urgent prospective, randomized, placebo-controlled clinical trials are warranted to validate these observations and further define optimal dosing strategies.”
Study Limitations — Read This Carefully
The 2026 paper is a preprint (not yet peer-reviewed) and has important limitations that should shape how you interpret the headline numbers:
- No control group. There was no matched cohort of cancer patients receiving usual care but not taking IVM/MBZ. Some of the observed benefit may reflect conventional treatments, lifestyle changes, disease biology, or regression to the mean.
- Self-reported outcomes. While some outcomes were supported by imaging or pathology, patient-reported results are subject to recall bias and selection bias.
- Selection bias. Patients who self-selected into an off-label telemedicine program may have differed systematically from average cancer patients — in disease stage, motivation, concurrent treatments, and resources.
- Confounding. Concurrent standard-of-care treatments (surgery, chemo, radiation, immunotherapy), diet, other supplements, and stage at enrollment were variables not uniformly controlled for.
- Heterogeneous cancers. The cohort included many different cancer types. Response to any single intervention is expected to vary dramatically by cancer type and stage.
- Preprint, not peer-reviewed. The paper has not yet passed independent peer review. That process may identify issues the authors have not addressed.
The authors themselves call for randomized, placebo-controlled trials. Until those trials exist, the 84.4% figure should be treated as a signal worth testing, not as evidence that IVM+MBZ cures cancer.
Proposed Mechanisms of Action
The biological rationale for studying these drugs in oncology draws on work published over the last 10–15 years:
Ivermectin
- Inhibits PAK1 — a kinase upregulated in many cancers and implicated in cell proliferation and survival
- Suppresses Wnt/β-catenin signaling — a pathway active in cancer stem cells in colorectal, breast, and other tumors
- Targets cancer stem cells — the small population of tumor cells thought to drive recurrence
- Disrupts mitochondrial function, triggering apoptosis in cancer cells that depend on altered metabolism
- Modulates autophagy — the cellular “recycling” pathway cancer cells use to survive stress
Mebendazole
- Microtubule disruption — binds tubulin and prevents microtubule polymerization, similar in mechanism to taxane chemotherapies
- Interferes with glucose uptake in rapidly dividing cells, targeting the Warburg metabolism many cancers rely on
- Inhibits angiogenesis (new blood vessel formation required for tumor growth) in preclinical models
- Induces apoptosis via multiple pathways (p53, Bcl-2)
These mechanisms are well-characterized in cell-line and animal studies. The question the 2026 cohort is attempting to address is whether they translate into meaningful clinical benefit in real human cancer patients.
Mebendazole vs. Fenbendazole
These are two distinct drugs, often confused. Both are benzimidazoles, both bind tubulin, and both are used as antiparasitics. But:
- Mebendazole is the drug used in the Hulscher/McCullough study and in most human clinical cancer research to date.
- Fenbendazole is used more often in veterinary medicine (the “Joe Tippens protocol” that went viral online used fenbendazole). It has been studied less in human cancer and is not FDA-approved for human use in the U.S.
They share overlapping mechanisms but have different pharmacokinetics and human safety data. They are not interchangeable and should not be treated as equivalent.
Other Relevant Research
- Mebendazole + temozolomide in brain cancer: A Johns Hopkins phase I trial reported safety and early efficacy signals of mebendazole combined with standard temozolomide chemotherapy for high-grade glioma.
- Ivermectin in breast cancer cell lines: Multiple in vitro studies have shown dose-dependent apoptosis and inhibition of proliferation in estrogen-receptor-positive and triple-negative breast cancer lines.
- Case reports: Individual case reports in peer-reviewed journals have described responses in pancreatic cancer, colon cancer, and melanoma using mebendazole protocols — but case reports cannot establish cause and effect.
Sources
- Primary preprint (open access): Zenodo #19455636 — Hulscher et al., April 2026
- McCullough Foundation: mcculloughfnd.org
- ResearchGate mirror: ResearchGate #403583165
Additional studies and updates will be added to this page as they are published.
Related Products — Virex Health (Affiliate)
SaltyFuelShop is an affiliate of Virex Health. Virex describes its antiparasitic and antibiotic products as pharmaceutical-grade, labeled and marketed for veterinary use (pets or fish). Because they are sold for animal use, they are not subject to FDA human-drug approval — but the active compound in each tablet is the same molecular entity used in the corresponding human medication. The difference is the regulatory pathway, not what’s in the tablet.
We include these products because readers frequently ask where to source pharmaceutical-grade versions of these compounds. We do not prescribe protocols and we are not a medical provider. Off-label human use of any product labeled for veterinary use, if contemplated, should be discussed with a qualified licensed medical provider. Each purchase through the links below supports this site at no extra cost to you. See our Affiliate Disclosure.
- PetMectin — described by Virex as “pharmaceutical grade pure Ivermectin for pets” (12 mg/tablet, 50 tablets). Same active ingredient as human-grade ivermectin, labeled for veterinary use.
- PetDazole — described by Virex as “pharmaceutical grade pure Fenbendazole for pets” (150 mg/tablet, 50 tablets). Same benzimidazole family as mebendazole (the drug used in the Hulscher study) but a distinct molecule with different pharmacokinetics and less human clinical data. Labeled for veterinary use.
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Disclaimer
The information on this page is for educational purposes only and does not constitute medical advice. It summarizes findings from published scientific studies and preprints; it is not a claim by SaltyFuelShop about any product, therapy, or treatment. Cancer is a serious, potentially fatal disease — please work with a qualified oncologist when making treatment decisions. Do not start, stop, or modify any cancer treatment based on information on this page. Statements regarding dietary supplements have not been evaluated by the FDA and are not intended to diagnose, treat, cure, or prevent any disease. The drugs discussed on this page are regulated pharmaceuticals; off-label use carries risks and should only be considered under the supervision of a licensed medical provider. Read our full Disclaimer and Affiliate Disclosure.