The antibiotic fenbendazole, which is used to treat parasitic infections in animals, has been promoted as an alternative cancer treatment in social media videos by unlicensed veterinarians and has spread in popularity since its appearance on the video sharing platform TikTok. Specialist cancer information nurses at Cancer Research UK say there is insufficient evidence to support the use of fenbendazole for humans cancer.
Several studies show that fenbendazole slows down cancer cell growth in lab cultures and in animals. But those studies don’t necessarily apply to people. The drug doesn’t appear to have gone through any randomized clinical trials in people, and it wouldn’t be safe to try to cure cancer in people without such trials.
The benzimidazole antibiotic fenbendazole (also called albendazole) has been shown to inhibit the polymerization of tubulin, a protein that makes up microtubules. Microtubules are part of the cytoskeleton, which provides shape and structure to cells. Microtubules are also required for cell division during mitosis. During this process, chromosomes must be evenly separated between two daughter cells. Drugs that interfere with the formation of microtubules have been found to cause cancer cell death, and fenbendazole is a well-known example of this type of drug.
In three experiments, we tested whether fenbendazole could alter the growth of EMT6 tumors in mice. Each mouse was injected with the drug three times daily, 50 mg/kg/day, i.p., either alone or in combination with 10 Gy of x-rays. The appearance and behavior of the mice were observed, and their weights were recorded at each tumor measurement. The growth of the tumors was measured until they reached a volume of 1000 mm3; tumor size measurements were then compared between groups. The results showed that fenbendazole did not alter tumor growth, either in unirradiated mice or in those treated with x-rays.