Could three antiparasitic drugs hold the key to fighting cancer? Early research and inspiring stories suggest they might, but the science isn’t settled. Here’s what you need to know to explore this frontier safely.
Cancer is a daunting diagnosis, and for natural health seekers, the buzz around ivermectin, fenbendazole, and mebendazole is hard to ignore. Canadian physician Dr. William Makis claims his protocol using these drugs has helped thousands, from pancreatic cancer patients to elite athletes, shrink tumors and reclaim hope. On X, stories of dramatic recoveries—like a 65-year-old with a 78% lung tumor reduction—are spreading fast, echoing Joe Tippens’ famous remission from stage 4 lung cancer using a dog dewormer. These affordable, accessible drugs resonate with those tired of conventional options. Yet, the FDA remains skeptical, citing a lack of human trials. So, what’s the truth? While early data and testimonials spark excitement, these treatments are unproven for cancer. Let’s dive into the science, risks, Dr. Makis’ credibility, and next steps to navigate this promising but uncertain path.

The Buzz: Antiparasitics as Cancer Killers

Dr. William Makis, a former nuclear medicine oncologist, has ignited hope with his 2024 protocol, published in the International Journal of Orthomolecular Medicine. He claims ivermectin, fenbendazole, and mebendazole can tackle aggressive cancers, including what he calls “turbo cancers” linked to mRNA vaccines. His approach combines these drugs with high-dose vitamin D, curcumin, and ketogenic diets to starve cancer cells, disrupt their structure, and boost immunity. Makis reports cases like a young athlete with leukemia achieving remission and a pancreatic cancer patient slashing tumor markers.

X is abuzz with similar stories. One user shared how fenbendazole shrank their sister’s ovarian tumors, while another credited ivermectin with halting breast cancer progression. These echo Joe Tippens’ 2016 story: given months to live, he used fenbendazole (a veterinary dewormer) and supplements, achieving full remission. Preclinical studies back the hype: ivermectin inhibits growth in 28 cancer types (e.g., breast, ovarian) by blocking signaling pathways. Mebendazole, FDA-approved for pinworms, shows promise in colorectal and brain cancers by disrupting microtubules. Fenbendazole, though veterinary, works similarly. These drugs are cheap—fenbendazole costs ~$10/month—and widely available, making them a beacon for those seeking alternatives.

Dr. Makis’ Credibility: Expertise and Controversy

Dr. Makis, a Canadian physician with a medical degree from McGill University, specialized in radiology, oncology, and nuclear medicine. He worked at the Cross Cancer Institute in Edmonton, contributing to over 100 peer-reviewed publications on PET/CT imaging and targeted radionuclide therapy, with 1,159 citations. His expertise in cancer diagnostics, having performed over 10,000 diagnoses, lends weight to his insights on repurposed drugs.

However, Makis’ credibility is polarizing. He lost his Alberta medical license in 2019 after professional misconduct complaints, including an incident where he allegedly confronted a colleague. His employment was terminated in 2016, and he was later declared a vexatious litigant in a wrongful dismissal lawsuit against Alberta Health Services. Makis has made unsubstantiated claims, such as linking COVID-19 vaccines to “turbo cancers” and alleging widespread cover-ups in healthcare. These views, shared on his Substack and podcasts, align with anti-vaccine narratives, drawing criticism from mainstream oncology and fact-checkers like Science Feedback, who note his cancer protocol lacks RCT evidence. Despite this, his Substack has a global following, and patients report success with his protocols. While his expertise is undeniable, his controversial claims and non-practicing status warrant caution when evaluating his recommendations.

Why the FDA Isn’t Convinced—Yet

The FDA hasn’t approved ivermectin, fenbendazole, or mebendazole for cancer. Ivermectin is cleared for parasitic infections and rosacea, mebendazole for pinworms, and fenbendazole only for animals. The FDA demands rigorous randomized controlled trials (RCTs) to prove safety and efficacy, but human trials for these drugs in cancer are nearly nonexistent. Only one ivermectin trial (for breast cancer) and a few for mebendazole are underway. Fenbendazole, as a veterinary drug, faces a steeper hurdle.

The FDA’s caution also stems from past misuse. During COVID-19, ivermectin overdoses from veterinary formulations led to hospitalizations, prompting warnings about unproven uses. Many natural health enthusiasts see this as Big Pharma bias, noting that generic drugs like mebendazole ($400/month in the U.S.) or fenbendazole ($10/month) lack the profit motive of patented chemotherapies. While economic incentives may shape research priorities, the FDA’s stance reflects a scientific gap: without RCTs, these drugs remain experimental. Off-label use is legal, but the agency warns of risks without standardized dosing or safety data.

The Science: Hopeful Hints, Big Gaps

The case for these drugs rests on preclinical studies and anecdotes, not human trials. In labs, ivermectin triggers cancer cell death (apoptosis) and blocks pathways like Wnt, which fuel tumor growth. A 2018 review found it effective against 28 cancers in vitro, including glioblastoma and leukemia. Mebendazole, studied since the 1990s, shrinks tumors in animal models of colon cancer and glioma by disrupting microtubules. Fenbendazole, less studied, shows similar effects, with a 2023 study suggesting it starves cancer cells by altering glucose uptake.

But preclinical success doesn’t guarantee human results. Only 3.4% of cancer drugs move from lab to approval. Human trials are sparse, and Makis’ protocol, while peer-reviewed, relies on case reports, not RCTs. His journal isn’t a top-tier oncology outlet, and his “turbo cancer” claims lack mainstream support. High doses needed for anticancer effects—far above parasitic doses—raise safety questions. For example, mebendazole at 1,500mg/day exceeds its 200mg/day pinworm dose, and fenbendazole’s 444mg/day is untested in humans. Without clinical data, we don’t know if benefits outweigh risks or how these drugs interact with chemo or radiation.

Risks to Know Before You Try

Exploring these drugs isn’t risk-free, especially with veterinary formulations like fenbendazole. Here’s what to consider:

  • Ivermectin: At high doses (e.g., 1mg/kg/day), it can cause nausea, dizziness, or rare seizures. Veterinary forms (e.g., 1.87% paste) risk inconsistent dosing or allergic reactions from untested excipients.

  • Mebendazole: Generally safe but can cause liver issues or low blood counts at high doses. As an FDA-approved drug, it’s safer than fenbendazole but costly without insurance.
  • Fenbendazole: Not approved for humans, it may cause stomach upset or unknown long-term effects. Anecdotal protocols lack clinical validation, and self-dosing risks toxicity.
  • General Risks: Self-medication can delay proven treatments like surgery or immunotherapy, worsening outcomes. Drug interactions (e.g., with blood thinners) are possible, and veterinary drugs may contain impurities.

Real-world risks are evident. In 2021, ivermectin overdoses from horse paste led to ICU admissions, and fenbendazole’s human safety remains unstudied. Working with an integrative oncologist is crucial to tailor doses, monitor bloodwork, and avoid dangerous errors.

A Hopeful Path Forward

Ivermectin, fenbendazole, and mebendazole offer a tantalizing glimpse at cancer’s future, blending natural health principles with cutting-edge science. Stories like Joe Tippens’ and Dr. Makis’ patients inspire hope, and preclinical data suggests these drugs could one day join the cancer-fighting arsenal. But we’re not there yet. The science lags behind the stories, and the FDA’s caution, while frustrating, reflects a need for proof over promise.
So, what can you do? Start by consulting an integrative oncologist who understands off-label therapies. They can guide you on mebendazole (the safest option) or explore ivermectin under supervision, avoiding veterinary fenbendazole unless part of a monitored plan. Pair these with evidence-based natural strategies like ketogenic diets or curcumin, which may enhance effects. Advocate for more research—ClinicalTrials.gov lists ongoing trials you can support or join. Share your story below to connect with our community, but always verify claims with science.
These drugs aren’t miracles, but they’re not hype either. They’re a call to action for natural health seekers to demand answers, explore safely, and push for a future where affordable remedies get the trials they deserve. Have you tried these therapies or heard success stories? Let us know, and let’s keep the conversation grounded in hope and truth.
Sidebar: Dr. Makis’ Dosing Protocols for Cancer

Dr. William Makis proposes the following off-label dosing protocols for ivermectin, fenbendazole, and mebendazole, tailored to cancer type and severity. These are experimental, lack RCT validation, and should only be used under medical supervision. Always consult an integrative oncologist before starting.

  • Ivermectin (taken 6 days on, 1 day off weekly for at least 3 months):
    • Low Dose (0.5mg/kg, 3x/week): For cancers in remission, high-risk individuals (e.g., family history), or prophylaxis. Example: A 60kg person takes ~30mg (2.5 x 12mg tablets) 3x/week.
    • Medium Dose (1mg/kg/day): For newly diagnosed cancers, including “turbo cancers” (e.g., lymphoma, breast, colon). Example: A 60kg person takes 60mg (5 x 12mg tablets) daily.
    • High Dose (2mg/kg/day): For aggressive cancers (e.g., pancreatic, brain, leukemias) with high Ki67 staining (>80%). Example: A 60kg person takes 120mg (10 x 12mg tablets) daily.
    • Note: Combine with benzimidazoles (below) for faster effects. High doses risk nausea, dizziness, or seizures.
  • Mebendazole (taken daily with food, ideally morning and evening):
    • Low Dose (200mg/day): For low-grade cancers or maintenance. Example: 100mg twice daily.
    • Medium Dose (400mg/day): For intermediate-grade cancers. Example: 200mg twice daily.
    • High Dose (1,500mg/day): For high-grade cancers (e.g., glioblastoma). Example: 750mg twice daily, best for brain cancers due to blood-brain barrier penetration.
    • Note: Safer than fenbendazole but risks liver issues or low blood counts at high doses.
  • Fenbendazole (taken 6 days on, 1 day off weekly):
    • Standard Dose (444mg/day): For most cancers, including “turbo cancers.” Example: 444mg powder or capsules daily.
    • High Dose (1,000mg, 3x/week): For aggressive cancers. Example: 1,000mg 3x/week.
    • Note: Veterinary drug, not FDA-approved for humans. Risks include stomach upset or unknown long-term effects.
  • Safety Tips:
    • Use human-grade ivermectin or mebendazole over veterinary forms to avoid impurities.
    • Monitor liver function and blood counts, especially with high doses.
    • Combine with ketogenic diets or curcumin for potential synergy, per Makis’ protocol.
    • Never self-medicate; misdosing risks toxicity or delayed treatment.
Source: Dr. Makis’ 2024 protocol and FirstMed Inc. Costs vary: ivermectin ($11.50/day for 60mg), fenbendazole ($10/month), mebendazole (~$400/month without insurance).
September 22, 2026 Update to this article:

Ivermectin, Fenbendazole, and Mebendazole: Promising Cancer Fighters or Unproven Hype? (2026 Update)

Updated September 2026

Few health topics generate as much heat as this one. On one side are patients, some of them people I know personally, who say these inexpensive antiparasitic drugs helped them beat cancer after conventional treatment failed. On the other side are the major medical organizations, which say the evidence isn’t there. Both sides tend to talk past each other.

This article lays out what the research actually shows as of 2026: what’s promising, what’s still missing, and what to ask your doctor if you’re considering it.

Why Researchers Got Interested

All three drugs have long track records treating parasitic infections. Scientists started paying attention when lab experiments showed that they affect processes cancer cells depend on. Some of these drugs disrupt the microtubules cells need to divide, and some interfere with how cancer cells process glucose for fuel. Mebendazole has a stronger anticancer rationale than ivermectin and more human data, especially in glioma, though it remains investigational. For ivermectin, a 2021 paper in NPJ Breast Cancer reported that it could help turn immunologically “cold” tumors “hot” and work together with immunotherapy drugs. Substack

Lab and animal results are where most cancer drugs start. The question is whether they hold up in people.

What the Human Evidence Shows

Fenbendazole case series (2025). A case series published in Case Reports in Oncology followed three patients with advanced cancers. Two patients with breast, prostate, and melanoma cancers achieved complete remission and one achieved near-complete remission after adding fenbendazole to their regimens alongside other therapies (not including chemotherapy). All three tolerated it without reported side effects, and remission held for 11 months to nearly three years. karger

Ivermectin plus mebendazole cohort (2026). This is the largest human study so far. Researchers followed 197 cancer patients who were prescribed the two drugs off-label through a U.S. telemedicine platform, collecting data through surveys at baseline and about six months later; 122 completed follow-up. The authors reported high rates of self-reported benefit and good tolerability, and they described the results as hypothesis-generating, calling for randomized controlled trials. Anticancer ResearchPubMed

Clinical trials underway. A Phase I/II trial combining ivermectin with immunotherapy in women with metastatic triple-negative breast cancer is ongoing, with an interim analysis published. A second trial, ICONIC, testing ivermectin with immune checkpoint inhibitors, was registered in March 2026. These are the studies that could answer the question. Keep-healthyclinicaltrials

What the Critics Say, and Why It Matters

If you’re going to take this topic seriously, you have to take the objections seriously too. Here are the main ones.

No comparison groups. None of the human studies above compared patients taking these drugs against similar patients who didn’t. That matters enormously. In the 2026 cohort, 28% of patients were also on chemotherapy, 22% on radiation, and 20% had surgery, and 78% were using other lifestyle, nutrition, or supplement strategies. Without a control group, there’s no way to tell which of those things produced the results. Keep-healthy

Self-reported outcomes. The 2026 cohort relied on patients reporting their own cancer status through surveys rather than scans or lab results confirmed by researchers.

Concerns about the 2026 paper. PubMed lists an Expression of Concern attached to the study. Scientists also raised questions about conflicts of interest and the peer-review process. PubMedThe Conversation

Negative results exist too. In a small trial, 8 patients with refractory gastrointestinal cancer took high-dose mebendazole; all had progressive disease at 8 weeks, and 4 progressed faster than expected. Keep-healthy

The official position. The American Society of Clinical Oncology (ASCO) strongly cautions against using ivermectin or fenbendazole to treat cancer, including alongside standard treatment, outside of a well-designed clinical trial. Fenbendazole has no FDA approval for any human use, and ivermectin is approved only for specific parasitic infections, at doses well below those in online cancer regimens. Aesthetics AdvisorAesthetics Advisor

Real Stories, Real Questions

I have two personal friends, both having been diagnosed with stage 4 prostrate cancer, and having unsuccessfully tired conventional treatments, are now cancer free after using these off-label remedies.

Stories like these are exactly why researchers are now running trials. They’re also why those trials matter. A case report tells you something remarkable happened to one person. A controlled trial tells you how likely it is to happen for the next person.

The Bottom Line

The honest answer to this article’s title is “neither yet.” There is a real signal: plausible biology, published case reports, a large observational cohort, and formal clinical trials now underway. But nobody has yet shown, in a controlled study, that these drugs improve survival.

If you’re considering any of these drugs:

  • Don’t stop or delay proven treatment based on an online protocol.
  • Tell your oncologist. The point isn’t judgment. It’s making sure nothing you take interferes with chemotherapy, immunotherapy, radiation, liver function, or blood counts. Substack
  • Ask about clinical trials. Enrolling in one gets you access to these drugs with medical monitoring, and it helps answer the question for everyone who comes after you.
  • Get liver function monitored. These drugs are processed by the liver, and liver enzyme changes have been reported with fenbendazole.

We’ll update this article as trial results come in.

Sources

  • Makis W, Baghli I, Martinez P. Fenbendazole as an Anticancer Agent? A Case Series of Self-Administration in Three Patients. Case Reports in Oncology. 2025;18(1):856–863.
  • Hulscher N, et al. Real-world Clinical Outcomes of Ivermectin and Mebendazole in Cancer Patients: Results from a Prospective Observational Cohort. Anticancer Research. 2026;46(6):3243–3255.
  • Draganov D, et al. Ivermectin converts cold tumors hot and synergizes with immune checkpoint blockade for treatment of breast cancer. NPJ Breast Cancer. 2021;7:22.
  • Yuan Y, et al. Phase I/II study of ivermectin with balstilimab in metastatic triple-negative breast cancer. Journal of Clinical Oncology. 2025;43(16 suppl).
  • ClinicalTrials.gov: Ivermectin Combined With Immune Checkpoint Inhibition in Cancer (ICONIC), NCT07487805.