Fenbendazole is not a proven treatment for cancer in people

A post on X, formerly Twitter, claims a drug called fenbendazole is  “a cheap cancer cure they don’t want you knowing about”. Similar posts have also been shared on Facebook. 

However, fenbendazole is not a recognized treatment for cancer and there is no reliable evidence to show that it will cure cancer in humans as suggested. 

Bad information about health can cause harm to people who use it to make decisions about their care.

We have written about similar claims before.

What is fenbendazole?

Fenbendazole is a drug that is used to treat parasitic infections in animals. It works by disrupting how parasites manage energy, which leads to their death. It is licensed for use in livestock and domesticated animals. 

Lab-based studies using human cells have shown that fenbendazole is able to kill cancer cells in various ways. It has also been shown to reduce both the aggressiveness and the number of large intestine tumours in mice cells. Other studies have shown that fenbendazole in combination with various vitamins can have anticancer effects in mice with lymphoma.

However, research on solid mammary tumour cells from mice showed no benefit in using fenbendazole either alone or in combination with radiation treatment. Other research has noted that the anticancer effects are limited as the drug is not very soluble.

Can it treat cancer in humans?

Clinical trials with fenbendazole would be required before it could be recommended as a treatment for cancer in people, and as we’ve said before there don’t seem to have been any. For example, we’d need to know more about which cancers it could be suitable for and whether it can be taken with other treatments.

The theory of fenbendazole as a cancer treatment gained prominence following the case of the American businessman Joe Tippens, who documented his cancer journey using social media. He reportedly became cancer-free after taking fenbendazole in combination with other alternative therapies, but he was also part of a clinical trial for other cancer treatments at the time.

In a discussion about fenbendazole on the BreastCancerOrg Podcast, oncologist Dr Brian Wojciechowski said ‘‘Well, it hasn’t been studied in human beings so we don’t know if it helps. But it’s almost as important that we don’t know if it's harmful either.’’

Specialist cancer information nurse at Cancer Research UK, Caroline Geraghty, previously told Full Fact: “Unsubstantiated claims that fenbendazole can cure cancer are misleading and can cause harm. Cancer patients should treat any information promoting unconventional treatments online with caution, and always discuss with their doctor before considering new therapies.”