Fenbendazole is a common dog deworming medicine. It has recently received attention for its supposed ability to cure cancer in people, with posts on social media such as Facebook and TikTok receiving millions of views. As the nonprofit organization Cancer Research UK tells Full Fact, however, there isn’t enough evidence that fenbendazole can cure cancer in humans. It hasn’t gone through the rigorous clinical trials that would be required to show that it is safe and effective.

Posts about a man named Joe Tippens whose cancer went into remission after he began taking fenbendazole on the recommendation of his veterinarian have gained traction on social media. But, as Health Feedback explains, there’s just not enough evidence to back up the claim that the drug can cure cancer. There could be other factors at play in his remission (such as conventional cancer treatments), and a randomized controlled trial would need to be conducted to determine whether the drug can actually help.

To test if fenbendazole can indeed kill cancer, researchers treated human non-small cell lung cancer cells with the drug and examined them for signs of toxicity. They found that fenbendazole did slow the growth of these cells, but it also caused them to die.

Researchers were able to establish that this cytotoxic effect is due to fenbendazole’s ability to destabilize microtubules and disrupt cellular division. This causes the separation of chromosomes during mitosis to be uneven, which leads to cell death. In addition, fenbendazole induces mitochondrial injury and caspase-3-PARP pathways that also lead to cell death in CRC cells. fenbendazole cancer