There’s no evidence that fenbendazole for cancer It hasn’t been studied in humans and it’s not a traditional cancer treatment.
Several posts and TikTok videos have made the claim that a dog deworming medication called fenbendazole can cure a variety of diseases including cancer. However, this is false.
ANThelmintic
Fenbendazole is a medication that is typically used to treat parasites and worms in animals, including roundworms, hookworms, whipworms, and some tapeworms. It is commonly sold under the brand names Pancur and Safe-Guard. However, the medication is also being used to treat cancer by some people as part of a treatment strategy known as the Joe Tippens Protocol.
While there are some studies that show fenbendazole can slow down cancer cell growth in cells and mice, there is insufficient evidence showing it cures cancer in humans. In fact, the anecdotal reports of a cancer patient who claimed to go into remission while taking fenbendazole may not be valid because it wasn’t taken in conjunction with conventional treatments like chemotherapy and radiation that could have also contributed to his remission. Furthermore, the mechanism of action fenbendazole has to kill cancer cells isn’t unique and there are already drugs on the market that act in a similar way.
CYP3A4 Inhibitor
A drug that can inhibit CYP3A4 and disrupt microtubules has shown anti-cancer effects in cells in culture and in mice. It stabilizes WT p53, provides moderate disruption of the mitotic spindle, interferes with cancer cell glucose metabolism and targets cell cycle arrest, all leading to decreased tumor growth in the lab and in live animals.
In one experiment, fenbendazole caused G2/M arrest and apoptosis in 5-FU sensitive SNU-C5 and resistant SNU-C5/5-FUR colorectal cancer cells. This cytotoxicity was attributed to the activation of p53-p21 pathways and partly to apoptosis, autophagy, and ferroptosis (Fig. 8A).
In another experiment, lymphoma-infected rats were divided into four groups and treated with a standard diet, vitamin supplementation only, a low dietary intake of vitamins, or a combination of both. The groups that received the combination of diet and fenbendazole showed the greatest reduction in tumor volume. In contrast, the group that received fenbendazole only showed moderate reduction in tumor volume. The results suggest that fenbendazole could be an effective treatment for cancer in humans.
Apoptosis Inhibitor
Researchers have found that fenbendazole inhibits cancer cell growth in both culture and animal models. It does so by acting as a microtubule destabilizer and inhibiting several different pathways that cause cell death.
The cellular autophagy process is also inhibited by fenbendazole. The drug binds to the LC3-I protein and causes it to be cleaved, which results in the accumulation of mitochondrial cytoplasmic fragments and other debris. This can lead to oxidative stress and caspase activation, which leads to apoptosis.
In addition, fenbendazole can induce necroptosis by affecting the interaction between RIP and RIP3 kinases, leading to the phosphorylation of MLKL. This leads to apoptosis, which can be augmented by ferroptosis, an alternative form of cell death.
In a recent study, researchers found that high doses of fenbendazole suppressed the growth of 5-fluorouracil-resistant colorectal cancer cells. Tumor growth was rigorously measured by comparing the time it took for tumors to reach four times their initial volume.
Microtubule Destabilizer
Fenbendazole is one of many benzimidazole anthelmintic drugs that have been repurposed as anti-cancer agents. These drugs are known to interfere with microtubules and cause cancer cell death via multiple pathways.
In a study on HeyA8 cells, fenbendazole induced a significant clonogenic assay inhibition rate (i.e., a significant decrease in the number of colonies formed) with concentrations as low as 5521 nM. The drug also inhibited mitosis, which is the process of cell division in which chromosomes are separated evenly during metaphase and anaphase, by blocking microtubule formation.
In another experiment, fenbendazole was administered to mice with local tumors. The drug prevented them from growing to four times their original volume, even after irradiation. Moreover, the appearance and behavior of the mice in the drug and control groups were similar. Additionally, there were no significant differences in the weights of the mice at each measurement point during the experiment. These results demonstrate that fenbendazole has a therapeutic effect on cancer and can be used as an alternative treatment for cancer patients.
