A Podcast Clip Doubled Ivermectin Prescriptions. Veterinary Professionals Need to Be Ready for the Conversation.

A new UCLA-led study published in JAMA Network Open has put a number on something many clinicians already suspected was happening. When actor Mel Gibson appeared on The Joe Rogan Experience in January 2025 and claimed that three friends with stage IV cancer had recovered after taking ivermectin and fenbendazole together, the clips went viral almost immediately. Tens of millions of views. And then, within weeks, prescriptions for both drugs started climbing.

The research team analyzed de-identified electronic health records from more than 68 million patients across the United States and compared prescribing patterns in the months following the podcast to the same period the year before. Overall prescriptions for the drug combination doubled. Among patients with a cancer diagnosis, prescribing rates were more than 2.5 times higher. In the South, they tripled.

That is not a rounding error. That is a single podcast episode measurably reshaping clinical behavior across the country.

What the science actually says

Ivermectin is an FDA-approved antiparasitic with a well-established safety profile for its indicated uses. Fenbendazole is a veterinary anthelmintic approved for use in animals and not approved for use in humans. Both drugs have shown some anti-cancer activity in laboratory and animal studies, and that part is real. Fenbendazole in particular has demonstrated an ability to inhibit cancer cell growth, induce oxidative stress, and enhance apoptosis in preclinical settings. But preclinical activity is not clinical efficacy, and no completed clinical trials have demonstrated that either drug is safe or effective as a cancer treatment in humans. The gap between a promising lab result and a proven therapy is exactly what clinical trials exist to close, and that work has not been done here.

Why this is a veterinary profession conversation too

Fenbendazole is a drug veterinarians know well. Safe-Guard, the brand name product cited in the Gibson interview, is a Merck Animal Health product used routinely in companion animal and livestock medicine. When a veterinary drug goes viral as a human cancer treatment, it lands in your exam room whether you expect it or not. Pet owners with cancer diagnoses, or with family members who have them, may ask you about it directly. They may already be using it. They may want to know if what they heard is true.

The honest answer is that the preclinical data is interesting and the clinical evidence does not yet exist. That distinction matters enormously, and it is one that a trusted clinician is far better positioned to explain than a social media algorithm.

The deeper issue the study raises

Lead researcher Dr. John Mafi put it plainly: when prescribing for an unproven cancer treatment more than doubles after a single podcast, the concern is not just about the drug. It is about whether patients are skipping or delaying treatments that are known to work in favor of something that has not been proven to help them. That delay is where the real harm lives.

The study is observational and cannot prove causation. But the signal is clear enough to take seriously. Celebrity health claims move fast. Evidence moves slow. The space between those two speeds is where patients make decisions that affect their lives, and clinicians and health systems have a role in meeting them there with information that is both timely and honest.

Your clients are listening to the same podcasts. Be the voice that gives them the full picture. Read the article here: https://www.healthaffairs.org/doi/10.1377/hlthaff.2024.00452