Cheap Drugs, Desperate Patients, Celebrity Endorsements
In January 2025, Mel Gibson went on Joe Rogan's podcast and claimed that ivermectin and fenbendazole cured Stage IV cancer in several of his friends. The clip went viral. Search volume for "ivermectin cancer" and "mebendazole cancer" spiked to all-time highs. Online communities that had formed during COVID around ivermectin pivoted seamlessly to cancer protocols. A physician named William Makis began collecting case reports on his website, eventually compiling over 480 testimonials of patients using antiparasitic drugs alongside conventional cancer treatment. In September 2024, he co-authored what he called "the first-in-the-world ivermectin, mebendazole, and fenbendazole protocol for cancer," which was published in a peer-reviewed journal.1,2
The narrative is seductive: cheap, safe, off-patent drugs that pharmaceutical companies don't want you to know about because they can't profit from them. The drugs cost less than $10 a pill. They've been used safely for decades to treat parasitic infections. They kill cancer cells in the lab. And your oncologist won't prescribe them because the system is rigged.
Some of this narrative contains real elements. The drugs are cheap. They do kill cancer cells in vitro. They have established safety profiles for their approved indications. But the distance between "kills cancer cells in a dish" and "treats cancer in a human body" is measured in billions of dollars, decades of failed trials, and roughly a 95% failure rate for drugs that enter clinical testing.2,3
The Lab Data Is Real. That's Not the Problem.
Mebendazole is a benzimidazole anthelmintic introduced for human use in 1971. Its primary mechanism is binding beta-tubulin in parasitic worms, disrupting microtubule formation. Cancer cells also depend on microtubules for division, which is why existing chemotherapy drugs like vincristine and paclitaxel target the same system. In cell culture, mebendazole inhibits proliferation across multiple cancer types at concentrations between 0.1 and 0.8 micromolar. It crosses the blood-brain barrier, which makes it theoretically interesting for brain tumors. It also appears to inhibit angiogenesis (new blood vessel formation that tumors need to grow) and may sensitize cancer cells to radiation.4,5
Ivermectin is a macrocyclic lactone antiparasitic that won its discoverers the 2015 Nobel Prize. In cancer cell lines, it inhibits multiple signaling pathways: Wnt/beta-catenin, Akt/mTOR, and STAT3. It induces oxidative stress, promotes apoptosis and autophagy, and may target cancer stem cells. Preclinical studies have demonstrated activity across more than 20 cancer types. Some evidence suggests it can inhibit P-glycoprotein overexpression, potentially reducing chemotherapy drug resistance.6,7
None of this is disputed. The preclinical data for both drugs is extensive and, in many cases, genuinely impressive. The question, as always, is whether any of it translates to humans.
Drug candidates that show effectiveness in cells and animals often fail in clinical trials. The overall probability that a drug entering Phase I will eventually be approved is approximately 5%.
Anticancer Fund evidence review, 2025Four Human Studies. One Win. Two Failures. One Stopped.
Mebendazole has more human cancer data than ivermectin, which makes the picture both clearer and more sobering. Four clinical studies have been published or completed:
The positive trial. Prospective, randomized, double-blind, placebo-controlled study. 40 patients with metastatic colorectal cancer received bevacizumab plus FOLFOX4 chemotherapy, with half randomized to add mebendazole 500 mg twice daily for 12 weeks.8
Results: Overall response rate 65% vs 10% (mebendazole vs placebo). Median progression-free survival 9.25 months vs 3 months. Significant decline in VEGF levels. Well tolerated.
Context: This is the single most cited study in the entire antiparasitic cancer movement. It is a legitimate RCT with a real control group. It is also 40 patients at a single center. No overall survival data was reported. It has not been independently replicated. One positive trial of this size, in one cancer type, with one chemotherapy backbone, does not establish a drug as a cancer treatment. It establishes that a larger trial is warranted.
Glioblastoma safety study. Dose-escalation trial of mebendazole (25–200 mg/kg/day) combined with temozolomide in 24 patients with newly diagnosed high-grade gliomas. Six-year observation period.9
Results: Safe and tolerable at doses up to 200 mg/kg/day. Main side effect: reversible liver enzyme elevation (Grade 3 ALT/AST in 4 patients at highest dose). Two patients remained on treatment over 5–6 years.
Key limitation: This was a safety study, not an efficacy study. It was not designed to determine whether mebendazole works against glioblastoma. It established that the drug can be given safely at high doses. The two long-term survivors are noteworthy but cannot be attributed to mebendazole without a control group.
Recurrent glioblastoma. Randomized, open-label Phase II trial. Patients with recurrent glioblastoma not eligible for re-radiation received mebendazole combined with either lomustine or temozolomide.10
Results: Failed to achieve the primary endpoint of 55% survival at 9 months. No evidence of meaningful clinical benefit.
What this means: In the cancer type where mebendazole's blood-brain barrier penetration should give it the greatest theoretical advantage, it did not work in an actual randomized trial.
Advanced gastrointestinal cancer. Phase 2a clinical study planned for 30 patients. Stopped after enrolling only 11. Individualized dosing with therapeutic drug monitoring attempted to reach target serum concentrations.11
Results: Could not reach or maintain target serum mebendazole concentrations despite doses up to 4 grams daily with drug monitoring. All 8 radiologically evaluable patients showed progressive disease at week 8. Four of 8 evaluable patients fulfilled criteria for hyperprogressive disease, meaning their tumors grew faster on mebendazole than on their previous treatment.
Critical finding: This is the study the protocol promoters never cite. Mebendazole's notoriously poor oral bioavailability meant that even with aggressive dosing and monitoring, therapeutic blood levels could not be consistently achieved. And in half of evaluable patients, the cancer accelerated. The study was stopped for futility.
The GI cancer Phase 2a found that half of evaluable patients had hyperprogressive disease. The mebendazole bioavailability problem remains unsolved.11
Nobel Prize for Parasites. No RCTs for Cancer.
Ivermectin's cancer evidence is almost entirely preclinical. There are no published randomized controlled trials of ivermectin as a cancer treatment in humans. A 2025 review in Current Oncology Reports evaluated the state of evidence and noted that while preclinical studies show activity across many cancer types, the leap to clinical practice has not been made. A clinical trial combining ivermectin with chemotherapy was registered (NCT05318469) but as of early 2026, results have not been published.6,7
The publications cited in the Makis protocol to support ivermectin dosing include a pharmacokinetic study in healthy adults (not cancer patients) and a study examining ivermectin safety in leukemia patients being treated for COVID-19 (not for cancer). Neither study assessed whether ivermectin has anticancer activity in humans.2
480 Case Reports Are Not 1 Clinical Trial
The Makis protocol, published in September 2024, recommends ivermectin at 1 mg/kg/day plus mebendazole at 1,000 mg/day (or fenbendazole as substitute), combined with a metabolic support stack. It is accompanied by over 480 collected case reports from patients who used these drugs, many of whom also received conventional chemotherapy, immunotherapy, or radiation simultaneously.1
Attribution Problem
Nearly every "success story" involves patients taking antiparasitics alongside standard oncology treatment (Keytruda, carboplatin, paclitaxel, etc.). When a tumor shrinks while a patient is on both immunotherapy and ivermectin, attributing the response to ivermectin is scientifically meaningless. This is exactly why controlled trials exist.1,2
Survivorship Bias
480 case reports of positive outcomes collected from self-selected patients who contact a website tells you nothing about the hundreds or thousands who tried the same protocol and saw no benefit, or whose cancer progressed, or who died. They don't write testimonials.2
Bioavailability Crisis
Mebendazole has notoriously poor and variable oral absorption. The Phase 2a GI cancer trial showed that even with therapeutic drug monitoring and doses up to 4g/day, target concentrations could not be maintained. The concentrations that kill cancer cells in dishes may not be achievable in human tumors at tolerable doses.11
Safety Record Is Real
Both drugs have decades of human safety data for their approved indications. Mebendazole has been used at high doses (40 mg/kg/day) for months to years for invasive echinococcus infections. Ivermectin's Nobel Prize-winning safety profile for parasitic disease is well-established. These are not inherently dangerous drugs at standard doses.4,6
Although these drugs have shown potential to fight cancer cells in petri dishes and laboratory animals, rigorous clinical trials in humans are missing. Regardless of what viral podcasts claim, much more conclusive proof is needed.
Anticancer Fund, 2025The Cruel Middle Ground
This is the cruelest story The Corneum has covered, because it involves people who are dying. When you have Stage IV cancer and conventional treatment has failed, the emotional logic of trying a cheap, safe, off-patent drug with interesting preclinical data is overwhelming. We do not judge anyone who makes that choice. We understand it.
But understanding it does not make it evidence. The preclinical data for both mebendazole and ivermectin is real and, in many studies, impressive. The mechanisms are pharmacologically plausible. These are not homeopathy or energy healing. These are real drugs with real biological activity against cancer cells in controlled laboratory conditions.
The human data, however, is thin and mixed. Mebendazole has one small positive RCT in colorectal cancer (n=40) that warrants a larger confirmatory trial. It also has a failed RCT in glioblastoma and a GI cancer study stopped early for futility where half of evaluable patients showed hyperprogressive disease. Ivermectin has zero published RCTs for cancer in humans.
The 480 case reports compiled by protocol promoters are testimonials from patients almost always receiving standard oncology treatment concurrently. They prove nothing about the antiparasitic drugs specifically. A collection of uncontrolled observations, no matter how large, does not become a clinical trial by reaching critical mass.
What should happen: Properly funded, adequately powered, multi-center randomized controlled trials of these drugs as adjuvants to standard chemotherapy. The colorectal cancer signal from the Hegazy trial is interesting enough to warrant this. The bioavailability problem needs pharmaceutical-grade reformulation. The cost of these trials would be modest by oncology standards. That they haven't happened yet is a genuine failure of the drug repurposing pipeline.
What is happening instead: Podcasts, testimonials, grey-market protocols, and desperate patients self-medicating while their oncologists often don't know. This is not medicine. This is what fills the space when medicine fails to investigate something it should.
Mebendazole and ivermectin kill cancer cells in dishes and animal models through plausible pharmacological mechanisms. In actual human trials, mebendazole has one small positive RCT, one failed RCT, and one study stopped because tumors grew faster on the drug. Ivermectin has zero cancer RCTs. The "480 case reports" are testimonials from patients on concurrent standard treatment. The drugs deserve proper trials. They do not yet deserve the word "treatment." If you have cancer, your oncologist is not hiding a cure from you. They are working with the evidence that exists.
Sources
- Makis W, et al. Ivermectin, mebendazole and fenbendazole protocol for cancer. Published September 2024. Based on preclinical studies, case reports, and pharmacokinetic data. No RCT data supporting the combination.
- Science Feedback. Lack of evidence for cancer treatment protocol that recommends antiparasitic drugs ivermectin and mebendazole. 2025. Fact-check: publications cited do not constitute reliable evidence of anticancer effects in humans.
- Anticancer Fund. Separating fact from fiction: repurposed drugs in cancer treatment. 2025. Response to Mel Gibson/Joe Rogan claims. Notes rigorous clinical trials are missing.
- Guerini AE, et al. Mebendazole as a candidate for drug repurposing in oncology: an extensive review of current literature. Cancers. 2019;11(9):1284. Comprehensive preclinical review: tubulin inhibition, angiogenesis inhibition, radiosensitization.
- Song B, et al. Repurposing of benzimidazole anthelmintics as cancer therapeutics. Cancers. 2022;14(19):4601. BBB penetration, bioavailability comparison, IC50 values across cancer lines.
- Patel Y, Chawla J, Parmar MS. Ivermectin in cancer treatment: should healthcare providers caution or explore? Curr Oncol Rep. 2025;27(9):1070–1079. Review: preclinical across 20+ cancer types, no published human RCTs for cancer.
- Juarez M, et al. The multitargeted drug ivermectin: from an antiparasitic agent to a repositioned cancer drug. Am J Cancer Res. 2018;8:317–331. Wnt/β-catenin, Akt/mTOR, STAT3 pathway inhibition.
- Hegazy SK, et al. Mebendazole; from an anti-parasitic drug to a promising candidate for drug repurposing in colorectal cancer. Life Sciences. 2022;299:120536. RCT, n=40, 65% vs 10% response rate, PFS 9.25 vs 3 months. Single center.
- Riggins GJ, et al. Mebendazole and temozolomide in patients with newly diagnosed high-grade gliomas: results of a phase 1 clinical trial. Neuro-Oncol Advances. 2021. n=24, safety study, safe at 200 mg/kg/day, 6-year follow-up.
- Patil VM, et al. Mebendazole plus lomustine or temozolomide in patients with recurrent glioblastoma: a randomised open-label phase II trial. EClinicalMedicine. 2022;49:101449. Failed primary endpoint (55% survival at 9 months).
- Nygren P, et al. A phase 2a clinical study on the safety and efficacy of individualized dosed mebendazole in patients with advanced gastrointestinal cancer. Sci Rep. 2021;11:9008. Stopped early (11 of planned 30). Could not achieve target concentrations. 4/8 patients hyperprogressive. All evaluable patients PD at week 8.