182 Cancer Patients Reported Using Fenbendazole at MD Anderson: ASCO 2026 Survey
A 2026 ASCO abstract documents 182 self-reported fenbendazole users at MD Anderson out of 297,223 visits — with 138 different dosing schedules. A prevalence snapshot with major implications for research design.
By Sanare Lab · July 28, 2026 · 4 min read
A 2026 retrospective analysis presented at ASCO found that 182 out of 297,223 cancer patients at MD Anderson Cancer Center (0.06%) self-reported using fenbendazole between 2020 and 2024 — with 138 different dosing schedules documented. The finding spotlights just how fragmented real-world fenbendazole use is, and why oncologists urgently need standardized data before any clinical guidance is possible.
A retrospective study conducted at MD Anderson Cancer Center and presented at the ASCO 2026 Annual Meeting (Abstract #818) has offered the first large-scale snapshot of fenbendazole self-use among actively treated cancer patients. Out of 297,223 patient visits reviewed between January 2020 and January 2024, 182 patients (0.06%) reported taking fenbendazole — and 499 (0.17%) reported using ivermectin.
The numbers look small, but the heterogeneity underneath them is striking: researchers documented 138 entirely different dosing schedules and frequencies among just 182 fenbendazole users. No two patients were doing the same thing.
Table of Contents
Study at a Glance
| Parameter | Detail |
|---|---|
| Presented at | ASCO 2026 Annual Meeting — Abstract JCO 2026;44(2_suppl):818 |
| Institution | MD Anderson Cancer Center, Houston, TX |
| Study period | January 2020 – January 2024 |
| Total patient visits reviewed | 297,223 |
| Fenbendazole self-reporters | 182 (0.06%) |
| Ivermectin self-reporters | 499 (0.17%) |
| Unique fenbendazole dosing schedules | 138 |
| Top cancer types | Metastatic disease, prostate cancer, colorectal cancer |
| Source | Self-report during clinical visits (not verified by records) |
Who Is Using Fenbendazole
Fenbendazole users at MD Anderson were most commonly patients with metastatic disease, followed by those with prostate cancer and colorectal cancer — patterns that closely mirror which cancer types dominate online fenbendazole communities (the Joe Tippens story originated with small-cell lung cancer, but prostate and colorectal have since become the most active communities).
Researchers were unable to determine where patients sourced their fenbendazole — veterinary granule packets (Panacur C / Safe-Guard), online supplement capsules, or overseas pharmaceutical-grade products — which itself reflects a key gap: there is currently no practical way for an oncologist to know what a patient is actually ingesting when they say "I take fenbendazole."
The Dosing Chaos Problem
The 138-schedule figure is the finding that most clearly explains why large-scale outcome analysis has been impossible so far. Some protocols used the Joe Tippens original (1 gram / day, 3 days on, 4 days off); others used continuous daily dosing; others used weight-based scaling; others cycled in and out with chemotherapy. Comparing clinical outcomes across 138 different regimens is functionally impossible without far more structured data collection.
This also means that anecdotal success stories — the "it worked for me" accounts that circulate in communities — can almost never be attributed to fenbendazole specifically: the schedule, dose, source quality, concurrent therapies, and tumor biology all differ from person to person.
ASCO's Position
This survey was presented in the context of ASCO's broader June 2026 clinical notice recommending against off-label fenbendazole and ivermectin use for cancer outside of formal trials. ASCO's specific concerns center on hepatotoxicity risk, CYP450 drug interactions (fenbendazole is metabolized through the same liver pathways as many chemotherapy agents), and the opportunity cost of patients reducing or abandoning proven therapies. The MD Anderson data does not show outcome data — it establishes prevalence and pattern — so it neither supports nor refutes efficacy claims.
What This Means
The study is best read as a call for better data infrastructure, not as a verdict. 0.06% of a major cancer center's patient population is a real number — small in percentage terms but representing hundreds of people nationally at institutions that don't track it at all. Without systematic capture of what patients are taking and at what doses, the oncology field cannot assess safety signals, cannot design appropriate trials, and cannot counsel patients with specific information. The 138-schedule problem is ultimately a symptom of a field that has not yet decided whether fenbendazole is worth studying properly.
For patients, the practical takeaway is straightforward: if you are using fenbendazole alongside conventional treatment, tell your oncologist — not because the evidence is settled in either direction, but because your treatment team cannot monitor for interactions or toxicity signals they do not know exist.
FAQ
What did the MD Anderson ASCO 2026 study find?
A retrospective review of 297,223 patient visits found that 182 patients (0.06%) self-reported fenbendazole use between 2020–2024, with 138 different dosing schedules. The study documents real-world use patterns, not clinical outcomes.
Why were there 138 different dosing schedules?
Fenbendazole has no approved human dosing protocol. Patients self-design regimens based on online communities, anecdotes, and practitioner opinions — leading to extreme variability that makes any comparative outcome analysis practically impossible.
Which cancer types used fenbendazole most?
Patients with metastatic disease in general, followed by prostate cancer and colorectal cancer specifically. This mirrors community demographics where those cancer types are most discussed.
Does this study prove fenbendazole works or doesn't work?
Neither. It is a prevalence and pattern survey with no outcome data. It establishes that fenbendazole self-use occurs at a measurable rate at major cancer centers — nothing more, nothing less.
Should I tell my doctor I'm taking fenbendazole?
Yes. Fenbendazole is metabolized via cytochrome P450 pathways shared by many chemotherapy agents. Your oncologist cannot monitor for interactions or toxicity without knowing what you're taking.
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References
- MD Anderson / ASCO 2026 Abstract: Fenbendazole and Ivermectin Use in Cancer Patients. J Clin Oncol. 2026;44(2_suppl):818. ascopubs.org
- ASCO Clinical Notice. Recommending Against Ivermectin and Fenbendazole for Cancer Treatment Outside Clinical Trials. June 2026. connection.asco.org
- Sanare Lab analysis: ASCO Warning on Fenbendazole and Ivermectin (2026)
Medical Disclaimer
This article is for educational and informational purposes only. It is not intended to be a substitute for professional medical advice, diagnosis, or treatment. Always seek the advice of your physician or other qualified health provider with any questions you may have regarding a medical condition. Never disregard professional medical advice or delay in seeking it because of something you have read on this website.
Sanare Lab
Science-based health education team reviewing published research on repurposed drugs, integrative oncology, and evidence-based protocols.