In recent years, some researchers have suggested that widely used antihelminth drugs—such as the dog wormer ingredient fenbendazole—may also be effective against cancer. While a few studies involving cancer cells in petri dishes and mice suggest that these antiparasitic medications could suppress the growth of some types of cancer, no peer-reviewed study has confirmed that anthelmintics can cure cancer in people. A 2020 study found that certain animal anthelmintics—such as fenbendazole—may have anti-cancer effects in humans but the road to making these medications into approved human cancer treatments is a long one.
Fenbendazole is a benzimidazole carbamate that acts as an inhibitor of cellular microtubules, preventing their formation and destabilizing existing ones. Microtubules are structures that bind and organize chromosomes within cells, which provide structure and function. Cancer cells often have abnormally shaped microtubules and rely on their growth for cell division and spreading, so inhibiting their formation may be a way to kill them.
Despite the lack of evidence, the claim that fenbendazole can cure cancer has spread online. For example, an unlicensed veterinarian has made videos claiming that taking fenbendazole along with several other supplements cured his lung cancer. His claims have received widespread attention in South Korea, where fenbendazole was briefly available for sale at pharmacies. The nonprofit organization Cancer Research UK tells PolitiFact that fenbendazole hasn’t undergone clinical trials to determine whether it is an effective cancer treatment and that there’s insufficient evidence it’s safe for use in humans. fenbendazole cancer