An ingredient found in dog wormers, called fenbendazole, has been promoted as a cure for human cancer on TikTok and Facebook. The claims are based on a video by veterinarian Andrew Jones, who says his client Joe Tippens took the drug to treat his small-cell lung cancer and survived. Jones has resigned from the College of Veterinarians in British Columbia and is open about the fact that his videos are not scientific.
The goal of this study is to analyze the cytotoxic effect of the two different commercial brands of fenbendazole, Panacur C and Safe-Guard 4, on human cancer cells in vitro. In addition, a dissolution study is also performed to simulate the ability of these fenbendazole formulations to dissolve adequately in human fluids and reach certain areas of the body.
Both the analytical standard fenbendazole and the two commercial formulations tested exhibit a cytotoxic effect on human cancer cell lines, especially MDA-MB-231 cells. However, the concentration of fenbendazole needed to kill half of the cancer cells was quite high. This is likely due to the formulation problems that hinder distribution of the compound in the human body.
The toxicity of fenbendazole is attributed to its effect on microtubules, which provide the structure of all cells. This is an established mechanism for many anticancer drugs. Moreover, fenbendazole appears to have similar effects on cancer cells outside living organisms and in mice. In fact, the drug has been shown to inhibit cancer cell growth by preventing the production of new proteins that form the microtubules.fenbendazole for humans cancer