Prescriptions for an antiparasitic drug combination surged after a celebrity endorsed it as an alternative cancer treatment during a highly viewed episode of Joe Rogan’s podcast, researchers report.

The episode, which featured actor Mel Gibson in January 2025, included claims about friends with stage 4 cancer who, according to Gibson, experienced remission after taking ivermectin and fenbendazole.

Research teams from the Virginia Tech Carilion School of Medicine, UCLA and the University of Michigan later examined data to see whether that discussion sparked changes in prescribing behavior.

By analyzing records from more than 68 million patients in ambulatory care settings, the study found that prescriptions for the antiparasitic combination ivermectin–benzimidazole rose sharply after the episode aired.

Here's What They're Not Telling You About Your Retirement

Overall prescribing levels nearly doubled within a month and increased two and a half times among cancer patients, according to results published Tuesday in JAMA Network Open.

The spike was most noticeable among men, White patients, adults between 18 and 64, and those living in southern states.

Gibson told Rogan that he had three friends with late-stage cancer and that “all three of them don’t have cancer right now at all.” He later described their treatment as “ivermectin, fenbendazole.”

This Could Be the Most Important Video Gun Owners Watch All Year

During the discussion, Gibson also expressed a broader belief in natural remedies, saying, “I don’t believe that there is anything that can afflict mankind that hasn’t got a natural cure for it.”

Ivermectin is approved for both humans and animals as an antiparasitic, while fenbendazole is a benzimidazole-class drug used to treat worms in animals.

No studies have demonstrated that either medication is effective against cancer in people.

Lead author Michelle Rockwell of Virginia Tech said clinicians often face difficult conversations when patients request drugs they believe could help them based on celebrity messages.

She noted, “That’s where I think these celebrity influencers really play a big role.”

Experts not involved in the research urged caution, emphasizing that the drug combination has not undergone clinical trials for cancer treatment.

Dr. Skyler B. Johnson of the University of Utah Huntsman Cancer Institute said some laboratory and animal studies suggest potential anti-cancer activity at doses considered toxic for humans.

Johnson also expressed concerns that ivermectin could interfere with how the body processes cancer therapies and other medications.

The researchers said their study was observational and could not prove that Gibson’s interview directly caused the increase in prescriptions.

They noted that some patients may have sought veterinary formulations of ivermectin without prescriptions.

They also acknowledged the possibility of misclassified cancer cases and uncertainty about whether patients used the drug combination alongside or instead of prescribed cancer therapies.

The study did not evaluate outcomes or safety data related to the drugs.

Physicians continue to advise patients to consult qualified healthcare professionals for medical guidance before making treatment changes.