A study published in JAMA Network Open found a spike in same-day prescribing of ivermectin combined with a benzimidazole after actor Mel Gibson endorsed the drugs as a cancer treatment on Joe Rogan’s podcast in January 2025.
Key Findings
Overall prescribing rates nearly doubled; among cancer patients, they rose 2.5 times. Larger increases were observed among men, White patients, people aged 18–64, and those in southern states.
Study Details
Researchers from Virginia Tech Carilion School of Medicine, UCLA, and the University of Michigan analyzed health records of over 68 million patients in ambulatory care settings.
The study did not measure safety outcomes; no clinical trials have supported the safety or effectiveness of ivermectin–benzimidazole for treating cancer. Lead author Michelle Rockwell noted the influence of celebrity endorsements on patient demands.
Expert Commentary
Dr. Skyler B. Johnson of the University of Utah Huntsman Cancer Institute stated that while some lab and animal studies show anti-cancer activity, the required dose would typically be toxic for humans. Johnson also expressed concerns about ivermectin’s interaction with cancer treatments and other medications.
Limitations
The study is observational and cannot prove causation. Prescriptions being ordered does not guarantee they were filled or used.
Other limitations include:
- Some patients may have obtained ivermectin without a prescription from agricultural retailers.
- Cancer status could have been misclassified.
- The study did not assess whether patients used ivermectin alongside or as a substitute for conventional treatment.