Can a Dog Dewormer Really Fight Cancer? The Truth About Fenbendazole, Ivermectin, and What Most Patients Are Never Told

"Your hope is not unreasonable. The science is real. And you don't have to walk this road alone."

— Dr Eugene Pretorius, Cancer SA Centurion

From Dr Eugene Pretorius

Patients ask me about fenbendazole and ivermectin almost every single week.

They come in with printouts, WhatsApp messages, stories of friends and family whose stage 4 cancer went into remission after taking a cheap dewormer from a pet shop. They want to know if it's real. They want to know if there's hope.

And here is what I tell them — the same thing I want you to hear today:

Your hope is not unreasonable. The science is real. And there is a clear, safe path forward.

What follows is not hype. It is not dismissal. It is the truth about three old, cheap, widely available drugs that are now at the centre of the most exciting conversation in cancer care — and how they fit into a real, powerful, personalised integrative cancer protocol in South Africa.

Read on. You are in the right place.

The Story That Changed Everything

In 2016, Joe Tippens — a businessman from Oklahoma — was diagnosed with stage 4 small-cell lung cancer. The tumours were everywhere: lungs, liver, pancreas, stomach, bladder, neck. His oncologist gave him three months.

Out of options, Joe did something unusual. On the advice of a veterinarian friend, he started taking fenbendazole — the dog dewormer you can buy at a pet shop — at 222 mg per day, three days on, four days off. He combined it with curcumin, CBD oil, and vitamin E.

A year later, his scans were clean. Every single tumour had disappeared.

Joe is still alive today. He tells his story to anyone who will listen. And the fact that he is still here, years later, is hard to ignore.

Joe's story is not alone. It is one of thousands of quiet whispers circulating in cancer communities worldwide. And the scientific establishment is finally starting to listen.

The Science: How These Old Drugs Attack Cancer

Fenbendazole, ivermectin, albendazole, and mebendazole are antiparasitic drugs that have been safely used in humans and animals for decades. In the laboratory, they do something genuinely interesting: they attack cancer cells from several different directions at the same time.

• Fenbendazole disrupts the internal "scaffolding" (microtubules) cancer cells need to divide, blocks glucose uptake by interfering with the GLUT-1 transporter and hexokinase — starving cancer of its favourite fuel — and switches on the p53 "guardian" gene that tells damaged cells to die
• Ivermectin — from the family of drugs that won the 2015 Nobel Prize in Medicine — disrupts the energy production of cancer cells and, importantly, appears to wake up the immune system against the tumour
• Albendazole (already FDA-approved for human use) chokes off the tumour's blood supply and disrupts cancer-cell division
• Mebendazole, fenbendazole's close cousin, has been the most tested in actual human cancer trials — especially for brain tumours

The Latest Peer-Reviewed Evidence (2024–2026)

This is the part that has changed the most recently. Over the last two years, a wave of new peer-reviewed studies has been published. Here is an honest summary of what they actually found — the encouraging parts and the caveats.

Fenbendazole — strong laboratory and animal evidence

• A 2025 study in Frontiers in Pharmacology showed fenbendazole triggers pyroptosis — an explosive, inflammatory form of cancer-cell death — in breast cancer cells and in mice, working through the HK2/caspase-3/GSDME pathway, with minimal toxicity to healthy tissue.¹
• A 2025 study in Translational Lung Cancer Research found that fenbendazole combined with a metabolism-targeting compound (diisopropylamine dichloroacetate) produced a synergistic anti-tumour effect against A549 lung cancer in mice — one of several papers showing fenbendazole works best in combination, not alone.²
• A 2024 BMC Cancer study confirmed fenbendazole's anticancer effect on ovarian cancer in both cell and animal models.³

Ivermectin — the first human trial and an NCI investigation

• The most important human data comes from a Phase 1/2 trial at Cedars-Sinai Medical Center, published in the Journal of Clinical Oncology (2025). It combined ivermectin with the immunotherapy drug balstilimab in metastatic triple-negative breast cancer — one of the hardest cancers to treat. In a small group of 8 evaluable, heavily pre-treated patients, the combination was safe and well tolerated, with a 37.5% clinical benefit rate at four months. In honesty: 6 of those 8 patients still progressed, and because ivermectin was given alongside approved immunotherapy, we cannot yet say how much of the benefit came from ivermectin itself. It is an encouraging early signal — not proof.⁴
• In early 2026, the US National Cancer Institute (NCI) confirmed it had run a preclinical (laboratory) study of ivermectin's "ability to kill cancer cells," with the NCI director noting there was "enough interest in it" to justify a proper look. Results are expected during 2026. This is a laboratory investigation — not yet an endorsement — but it is a striking sign that the question is being taken seriously at the highest level.⁵

Mebendazole — the one with the most human trial data

• A Phase 1 trial (Johns Hopkins) combined mebendazole with standard temozolomide in newly diagnosed high-grade brain tumours (gliomas), reporting a median overall survival of 21 months, with 41.7% of patients alive at two years — with acceptable safety at doses up to 200 mg/kg.⁶
• A Phase 1 trial in children (published in Neuro-Oncology Practice, December 2025) established the safety and maximum tolerated dose of oral mebendazole in paediatric patients with refractory or recurrent brain tumours — extending this research to the hardest childhood cancers.⁷
• A randomised Phase 2 trial (2022) tested mebendazole added to chemotherapy in recurrent glioblastoma, and a 2025 study in Cells mapped a new mechanism by which mebendazole kills ovarian cancer cells (the Girdin/AKT/NF-κB pathway).⁸
• A 2026 systematic review in the British Journal of Clinical Pharmacology pulled together the entire body of evidence on mebendazole for brain tumours — a sign this repurposed drug is now being evaluated with the same rigour as any mainstream candidate.⁹

A real-world look at ivermectin + mebendazole together

A 2026 prospective observational cohort in Anticancer Research followed 197 cancer patients taking ivermectin plus mebendazole off-label. It reported a clinical benefit ratio of 84.4%, with about half the group describing regression or no current evidence of disease. This sounds dramatic — but the authors themselves were clear that the study relied on self-reported outcomes with no control group, so the results are "hypothesis-generating" only, and urgently need randomised, placebo-controlled trials to confirm.¹⁰

Alongside these, researchers at the Anticancer Fund (Belgium) and the ReDO Project (Repurposing Drugs in Oncology) continue to systematically build the evidence base for these and other repurposed medicines.

An Honest Word on the Limits

I would be doing you a disservice if I only told you the encouraging half. So here is the honest picture, in plain language:

• Most of the strongest evidence is still in cells and animals, not large human trials. Laboratory results are a starting point, not a guarantee of what happens in a person.
• The human data we do have is small or uncontrolled — a handful of patients in the ivermectin breast-cancer trial, and a self-reported cohort with no comparison group. These generate hope and justify bigger trials; they do not prove a cure. (One widely-shared 2025 fenbendazole "case series" was in fact retracted by its journal — a reminder to weigh the source, not just the headline.)
• Fenbendazole is poorly absorbed when swallowed. A 2024 Anticancer Research review pointed out that oral fenbendazole may not reach high enough levels in the bloodstream to affect tumours — which is exactly why dose, formulation, and monitoring matter, and why buying pet-shop paste and hoping for the best is a poor strategy.¹¹
• None of these drugs is approved as a stand-alone cancer treatment. They are being studied as additions to proven care, not replacements for it.

This is not a reason to lose hope. It is a reason to do this properly, with a doctor — so you get the genuine benefit of these medicines without gambling with unproven doses or abandoning treatments that are already working for you.

Where Repurposed Drugs Become Truly Powerful

Taken alone, fenbendazole or ivermectin is promising. Combined with the rest of an integrative cancer protocol, they become something extraordinary.

At Cancer SA, we do not use repurposed drugs in isolation. We layer them into a personalised protocol alongside our two most effective cancer treatments:

• IPTLD low-dose chemotherapy — uses insulin to open cancer cell membranes, making them dramatically more vulnerable to what comes next
• High-dose IV Vitamin C — floods the cancer cell with targeted oxidative stress while sparing healthy cells
• Repurposed drugs — then close the cancer's remaining metabolic escape routes (fenbendazole blocks glucose, ivermectin disrupts energy production, albendazole cuts off blood supply)

Four mechanisms, attacking the same cancer, at the same time. No escape.

This is the kind of layered, mechanism-driven protocol that conventional "one drug at a time" oncology simply cannot offer — and it is exactly what we do every week at Cancer SA.

Read more about IPTLD cancer treatment Read more about IV Vitamin C

What We Do at Cancer SA

When you walk into our clinic in Centurion, Pretoria, we do not offer you a one-size-fits-all protocol. We sit down with you. We listen. We look at your specific cancer, your test results, your current treatments, your goals, and your fears.

Then we build a personalised plan that combines the best of:

• IPTLD — Insulin Potentiated Targeted Low Dose chemotherapy
• High-dose IV Vitamin C therapy
• Repurposed drugs — fenbendazole, ivermectin, albendazole, mebendazole
• Ozone therapy and hyperthermia
• Chelation and heavy metal detox
• Targeted nutrition and metabolic support

All under the supervision of Dr Eugene Pretorius — MBChB (University of Pretoria), MBA, 25+ years in integrative medicine, ACAM (American College for Advancement in Medicine) certified, IPTLD trained.

This is what we do every week, for patients from across South Africa — Centurion, Pretoria, Johannesburg, Midrand, and beyond. You are not a number. You are not a file. You are a person fighting for your life, and we will fight alongside you.

Before You Explore Repurposed Drugs — Know This

If you are thinking about fenbendazole, ivermectin, or any repurposed drug — please do not do it alone. You deserve more than a social media protocol. You deserve:

• A personalised dose based on your weight, liver function, and cancer type
• Regular blood monitoring to catch side effects early
• Drug interaction screening with your existing treatments
• Proper combination with IPTLD, IV Vitamin C, and supportive therapies
• A doctor who knows this territory and walks it with you

The patients who go it alone often get a fraction of the benefit — while taking all of the risk.

You don't have to do this alone. You shouldn't. And you're not going to.

Hope is not wishful thinking. Hope, backed by science and integrative medicine, is how cancer patients take back their lives.

We would be honoured to walk this road with you.

References

1. Pan H, Jin M, Huang Q, et al. (2025). "Fenbendazole induces pyroptosis in breast cancer cells through HK2/caspase-3/GSDME signaling pathway." Frontiers in Pharmacology. PubMed Central
2. Nguyen, et al. (2025). "Synergistic anti-tumor effect of fenbendazole and diisopropylamine dichloroacetate in immunodeficient BALB/c nude mice transplanted with A549 lung cancer cells." Translational Lung Cancer Research. Translational Lung Cancer Research
3. "Transcriptome analysis reveals the anticancer effects of fenbendazole on ovarian cancer: an in vitro and in vivo study." (2024). BMC Cancer. Springer
4. A phase I/II study evaluating the safety and efficacy of ivermectin in combination with balstilimab in patients with metastatic triple-negative breast cancer. (2025). Journal of Clinical Oncology, 43(16_suppl):e13146 (Cedars-Sinai Medical Center, NCT05318469). ASCO / JCO
5. "US Cancer Institute Studying Ivermectin's Ability To Kill Cancer Cells." (Feb 2026). KFF Health News. KFF Health News
6. "Mebendazole and temozolomide in patients with newly diagnosed high-grade gliomas: results of a phase 1 clinical trial." Neuro-Oncology / PMC (Johns Hopkins). PubMed Central
7. Phan P, Stapleton SL, Riggins GJ, et al. (2025). "Phase 1 study of mebendazole therapy for refractory/progressive or recurrent pediatric brain tumors." Neuro-Oncology Practice, 12(6):1092. Oxford Academic
8. "Mebendazole plus lomustine or temozolomide in patients with recurrent glioblastoma: a randomised open-label phase II trial." (2022). PubMed Central. See also: "Mebendazole Exerts Anticancer Activity in Ovarian Cancer Cell Lines via a novel Girdin-mediated AKT/IKKα/β/NF-κB Signaling Axis." (2025). Cells. PubMed Central
9. Blum CB, et al. (2026). "From anthelmintic to neuro-oncology: A systematic review of mebendazole repurposing for brain tumour therapy." British Journal of Clinical Pharmacology. Wiley Online Library
10. "Real-world Clinical Outcomes of Ivermectin and Mebendazole in Cancer Patients: Results from a Prospective Observational Cohort." (2026). Anticancer Research, 46(6):3243. Anticancer Research
11. "Oral Fenbendazole for Cancer Therapy in Humans and Animals." (2024). Anticancer Research, 44(9):3725. Anticancer Research

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This article is for educational purposes and does not constitute medical advice. None of the drugs discussed are currently approved as monotherapy for cancer. Do not take any of these medications without consulting a qualified integrative oncology doctor. Self-medication, particularly with veterinary products, can cause serious harm. Individual results vary. At Cancer SA, we provide personalised, supervised integrative cancer care — not protocols you follow alone.