Fenbendazole Use in Humans
Fenbendazole is NOT approved for human use by the FDA or EMA and should not be recommended for any human medical condition, including cancer. 1, 2
Regulatory Status and Approved Human Alternatives
Fenbendazole is a benzimidazole anthelmintic approved exclusively for veterinary applications in animals such as dogs, pigs, and pheasants. 3, 4
For human parasitic infections, the approved benzimidazole alternatives are albendazole and mebendazole, which have established safety profiles and dosing regimens in humans. 1
The pharmacokinetics, safety profile, and appropriate dosing of fenbendazole in humans remain poorly documented in medical literature. 1
Specific Human Antiparasitic Treatment Recommendations
When treating parasitic infections in humans, use these evidence-based alternatives instead:
For Hookworm (Ancylostoma/Necator)
- Albendazole 400 mg PO daily for 3 days is the recommended treatment. 5
For Whipworm (Trichuris trichiura)
- Mebendazole 100 mg PO twice daily in combination with ivermectin 200 μg/kg PO once daily for 3 days is recommended, particularly for heavy infections. 5
For Pinworm (Enterobius vermicularis)
- Albendazole 400 mg or mebendazole 100 mg as a single dose is the standard treatment. 5
Documented Risks of Fenbendazole Self-Administration in Humans
Hepatotoxicity
Severe drug-induced liver injury (DILI) with hepatocellular pattern has been documented in patients self-administering fenbendazole based on unverified social media claims about anticancer effects. 3, 2
One case involved an 80-year-old woman with NSCLC who developed severe liver dysfunction after one month of fenbendazole use, which resolved only after discontinuation. 3
Another case documented histologically confirmed severe DILI in a 67-year-old woman presenting with jaundice after fenbendazole self-administration, requiring 3 months for liver function normalization. 2
Lack of Anticancer Efficacy Evidence
Despite social media claims, the patient with NSCLC who self-administered fenbendazole experienced no tumor shrinkage. 3
While preclinical studies suggest potential anticancer mechanisms (inhibiting glycolysis, inducing oxidative stress, enhancing apoptosis), clinical trials assessing anticancer effects, optimal doses, and tolerance profiles have not been performed. 1
Critical Clinical Pitfall
Physicians must specifically inquire about self-administration of veterinary medications, dietary supplements, and bioactive compounds when patients present with unexplained adverse reactions, particularly liver dysfunction. 3 Social media platforms like Twitter and Facebook disseminate unproven medical information that patients may act upon without medical supervision. 3