The anthelmintic drug fenbendazole is known to kill parasites in animals, but it’s not approved by the FDA for use against human cancer. That doesn’t stop people from using the drug off-label as a cancer treatment, but it’s a dangerous practice and hasn’t been proven to be effective. A recently published paper in Nature shows that fenbendazole works with dichloroacetate (DCA) to destroy human cancer cells and stop them from growing. While the research is promising, we can’t say for sure that fenbendazole for humans will cure cancer or prevent it from reoccurring because the anecdotal evidence on which the claim is based isn’t convincing.
In addition to its antiparasitic effects, fenbendazole is also reported to have antitumor properties and inhibit microtubule polymerization in a number of species including humans . This property has led to the repurposing of this class of drugs for the treatment of a variety of diseases, especially cancer.
One of the first case reports on a human patient who self-administered fenbendazole to treat nonsmall cell lung cancer (NSCLC) was published in 2018. This patient received information about this medication from social media, and she started taking it alone in lieu of her PD-1 inhibitor, pembrolizumab. Nine months later, she developed severe liver injury and stopped taking fenbendazole. This patient did not experience tumor shrinkage, but she did notice that her liver enzymes improved upon discontinuation of the medication.
A recent study in SNU-C5/5-FUR human colorectal cancer cells showed that fenbendazole activates autophagy and induces ferroptosis via decreased expression of Glutathione Peroxidase 4 (GPX4), triggering mitochondrial damage and subsequent cell death. In the same study, fenbendazole was shown to decrease the activation of p53, thereby allowing for the occurrence of mitochondrial apoptosis.
According to the World Health Organization, a large number of cases have been documented in which people have used fenbendazole to treat their cancers, but most of these cases weren’t verified by scientists. As a result, the WHO states that fenbendazole isn’t an effective treatment against cancer and doesn’t recommend its use.
The FDA tells Full Fact that “there is no evidence to suggest fenbendazole can cure cancer.” It hasn’t been approved by the FDA for that purpose, and it hasn’t undergone clinical trials on humans to prove its effectiveness or safety.
If you or a loved one are suffering from cancer, please seek medical care instead of relying on unsubstantiated anecdotal claims on the internet. There are plenty of other conventional cancer treatments that have been tested in randomized, controlled clinical trials and have proven to be effective. These options can include surgery, chemotherapy, radiation, and immunotherapy. They can also be combined to provide a more effective treatment. If you’re interested in pursuing alternative medicine for your cancer, talk to your doctor about the pros and cons of these treatments before making any decisions.