During a Jan. 9 appearance on the "Joe Rogan Experience" podcast, actor Mel Gibson claimed he knew multiple people who cured their cancer by taking ivermectin or fenbendazole, drugs commonly used to treat parasites in humans or animals. Claims that ivermectin or fenbendazole effectively treat or cure cancer are not supported by medical evidence. While some preclinical studies showed promising results, experts in cancer research and pharmacology say human clinical trials are needed to show evidence of the drugs’ effectiveness for use in cancer treatment.
Actor Mel Gibson appeared on the "Joe Rogan Experience" podcast on Jan. 9.
During the interview, Gibson claimed he knew three friends with stage four cancer who "don't have cancer right now at all."
When host Rogan asked Gibson if his friends took ivermectin or fenbendazole — drugs commonly used to treat parasites in humans or animals — Gibson nodded.
Gibson did not clarify whether his friends received traditional evidence-based cancer treatments in addition to the drugs mentioned.
The received more than seven million views.
In a platform, formerly known as Twitter, former Alberta doctor Viliam Makis — who also goes by the name William and whose — claimed he treated one of Gibson's friends with the drugs.
"I'm glad (Gibson is) shining a light on the cancer successes of repurposed drugs," Makis wrote.
Rating: Lacks evidence
Ivermectin is an antiparasitic drug approved in Canada for veterinary and human use.
In humans, ivermectin can be ingested orally as a treatment for parasites or used topically for the skin condition rosacea.
A notes ivermectin is not approved for use to prevent or treat COVID-19 and there is no evidence to suggest it works as a COVID-19 treatment.
The health agency said ºÚÁϳԹÏÍø poison centres saw an increase in reports about ivermectin over the summer of 2021.
Fenbendazole is an antiparasitic drug used to treat parasites in animals and is not approved for human use by Health Canada, according to its .
Neither drug is approved by Health Canada for the treatment of cancer.
Studies show no evidence ivermectin or fenbendazole cure cancer
, research director and staff physician at the Princess Margaret Cancer Centre in Toronto, said his own lab looked at the effects of ivermectin in leukemia cells about 15 years ago.
"We showed that it impacts the flow of salts into leukemia cells and changes cell features … and ultimately results in the death of leukemic cells over normal cells," he said.
However, Schimmer said that while there are "quite a number" of papers that have looked at ivermectin, fenbendazole or similar drugs and cancer, those studies were largely done in petri dishes or with animal subjects using a large concentration of the drugs.
"While the mechanisms of course are very interesting and might point to treatment strategies, there's no indication that this can be successful when given to patients," he said.
Schimmer said it's unclear whether scientists could achieve a dose of the drug that could be effective against cancer or is safe for patients to consume.
Most ivermectin and fenbendazole studies related to cancer are preclinical, meaning the drugs aren't ready to be tested by humans.
"It would be unwise to move from petri dish to just randomly treating people in private offices or even without medical supervision, because you get really serious adverse effects from trying to do something like that," Schimmer said.
Before a drug can be prescribed to patients, it needs to go through rigorous clinical trials, he added.
, staff internist and head of pharmacology at the Sunnybrook Health Sciences Centre in Toronto, said such a trial would involve treating one group of cancer patients with the drug and one group with standard cancer therapies, following both groups over time.
“If ivermectin was an effective therapy, it would be shown in a trial like that … no such trial has ever been published,†Juurlink said.
Taking drugs without medical supervision could have negative health impacts
Gibson's podcast appearance prompted the ºÚÁϳԹÏÍø Cancer Society to release a statement about the potential impacts of his claim.
"Mel Gibson promoted drugs that are not scientifically proven cancer treatments. Misinformation on cancer treatment is dangerous, cruel, irresponsible and gives false hope to people with cancer and their loved ones," the society on Jan. 10.
"Choosing to use an alternative therapy can have serious health effects, such as the cancer spreading or getting worse,†the society wrote.
Schimmer said using ivermectin without supervision could amplify the drug's side-effects, ranging from nausea and vomiting to more serious health impacts like seizures or even death.
Juurlink said such side-effects in ivermectin and fenbendazole are rare.
“All drugs have side-effects, but these are relatively safe medications,†Juurlink said, adding that fenbendazole in particular is not absorbed well by humans and thus has few side-effects.
However, he said the claims from Gibson and Makis about the drugs’ success in treating cancer could cause patients to turn away from evidence-based treatment.
Patients can pursue alternative cancer treatments safely
Schimmer, who treats leukemia patients as a staff physician, said it's common for them to request ivermectin and other unproven or alternative cancer therapies.
He said there's nothing wrong with pursuing certain alternative therapies in conjunction with evidence-based treatment, such as taking over-the-counter herbal supplements, as long as the patient informs their doctor and is made aware of potential risks.
Schimmer said patients interested in ivermectin as a cancer treatment would be better off participating in a formal clinical trial "that's regulated, controlled and closely monitored."
Sources
, PowerfulJRE, on YouTube, Jan. 9, 2025 ()
X from user @MakisMD on Jan. 10, 2025 ()
Health Canada on ivermectin from Oct, 19, 2021 ()
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X from the ºÚÁϳԹÏÍø Cancer Society on Jan. 10, 2025 ()
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CLARIFICATION: This fact check was updated on Jan. 17, 2025 to clarify Juurlink's comments about how fenbendazole is absorbed.
