Fenbendazole
Claimed for: Cancer
A dog dewormer at the centre of the most viral cancer-cure story of the last decade.
01The claim
That fenbendazole, a benzimidazole dewormer sold for dogs, cures late-stage cancer by disrupting the microtubules cancer cells need to divide.
02Origin
Traced to Joe Tippens, a US man diagnosed with small-cell lung cancer in 2016 who took fenbendazole alongside an experimental immunotherapy trial and later reported being cancer-free. His blog went viral in 2019. The immunotherapy trial he was enrolled in is rarely mentioned in retellings. The story now sustains a large Facebook and Reddit community trading protocols.
03What's known
Benzimidazoles do interfere with microtubule formation, which is a real anticancer mechanism used by approved drugs like the taxanes. That makes the hypothesis worth testing, and a small number of researchers say so. What does not exist is a human trial. Every widely shared success story involves either concurrent conventional treatment, an unverified diagnosis, or no follow-up. Case reports of liver injury from self-administered fenbendazole have appeared in the medical literature since 2021.
Documented risk
Not approved for humans in any country. Reported cases of drug-induced liver injury, some severe. Frequently taken alongside stopping conventional treatment, which is the larger danger.