Fenbendazole (brand names Panacur C ®, Safe-Guard ®) is a veterinary medication introduced in 1974. Worldwide, veterinarians commonly use fenbendazole, FBZ, to treat a variety of parasites in animals, such as tapeworms, hookworms, roundworms, lungworms, and whipworms. Fenbendazole has been known to have a high safety margin for animal use as it is tolerated well, has low side effects, and has a low degree of toxicity.
Following anecdotal fenbendazole cancer success stories to treat their cancer, researchers have been experimenting with the “repurposed” use of Fenbendazole for cancer – for animals and humans. Drug “repurposing” is a new use for a medicine that is different than the original medical indication. Though the Fenbendazole studies are limited, what researchers have found so far is promising for patients with cancer.
Fenbendazole has been studied for its potential to interfere with the glucose intake of cancer cells. Glucose is essential for cancer growth and proliferation.
This interference leads to a decrease in cancer cells both in laboratory settings and in live subjects. It starves the cancer cells of the glucose they need to grow and divide.
Fenbendazole was shown to kill cancerous cells and promote regression in cancer patients with large B-cell lymphoma that had metastasized. It was also found for other metastatic malignancies such as bladder cancer, renal cell carcinoma, and more.
Fenbendazole is not the only anti-parasitic medication being studied to fight cancer in humans. Fenbendazole is part of a larger group of benzimidazoles, anthelmintic drugs (i.e., drugs that kill parasitic worms). Ivermectin is another anti-parasite drug. The other benzimidazoles are approved for human use and are available by prescription only. Many studies have shown that the repurposed use of benzimidazoles can have prominent anticancer activity. Benzimidazoles include mebendazole (MBZ), albendazole (ABZ), flubendazole (FLU), fenbendazole (FBZ), oxibendazole (OBZ), and febantel (FBT).
Of all of the benzimidazole medications, the two that patients most commonly use at this time to fight cancer are Mebendazole and Fenbendazole. Both have been found to be effective at killing cancer cells, shrinking tumors, and reducing multi-drug resistance.
Clinical Research about Fenbendazole and Mebendazole for Cancer
In recent years, scientists have ramped up their efforts to study Fenbendazole, also called FenBen/FBZ, in clinical trials. The most recent studies have also shown Fenbendazole can potentially be used to treat pancreatic, ovarian and colorectal cancer.
Fenbendazole, also called “FenBen”/ FBZ, and Mebendazole (MBZ) are often confused because they perform the same primary function of eliminating parasitic worms. However, a key difference is that FBZ has not been approved for human use while MBZ has been approved for human consumption by governing bodies such as the Food and Drug Administration (FDA). Fenbendazole is only officially approved for veterinary use.
Researchers have found Mebendazole to have anticancer properties like Fenbendazole. Several preclinical studies suggest that Mebendazole helps stop tumor progression, has cytotoxic activities, reduces tumor growth, and can help improve survival. Unlike Fenbendazole, Mebendazole has been found to cross the blood-brain barrier, which can be very helpful in brain cancers and cancer that has metastasized to the brain.
In a study done in 2021, scientists discovered that MBZ can stop some proteins (called HIFs) from working in breast cancer cells. This is helpful for treating breast cancer because MBZ not only works like a chemotherapy drug, but it may also stop cancer cells from becoming resistant to chemotherapy
While Fenbendazole for human cancer has gained more popularity in recent years, especially related to Joe Tippens’ cancer-fighting story, some research available at this time suggests Mebendazole might be more effective for treating some different types of tumors. For example, research studies have shown that MBZ could be more effective for brain and ovarian cancers. Fenbendazole has been found to be very effective against metastatic melanoma, lung cancers, and lymphoma. Anecdotally, both MBZ and FBZ have shown effectiveness against many cancer types, including when paired with vitamins, supplements, repurposed medications, alternative treatments, and standard of care treatments.
How Does Fenbendazole Work for Cancer?
Fenbendazole, like the other benzimidazoles, is a microtubule inhibitor. Microtubules are like little ropes that are used to move things around inside the cell. When microtubules are prevented from doing their job of helping cells divide and reproduce, especially in cancer cells, the cancer cells will die. FBZ helps with cancer cell death. Research has shown that FBZ does not have the same impact on healthy cells.
Fenbendazole can work alongside traditional cancer therapies to decrease cancer cells. For example, one study found that FBZ can treat cancer by inhibiting the cancer cell’s glucose intake and acting as an interfering agent that blocks multiple cellular pathways in cancer cells.
The positive results of research about Fenbendazole as an anticancer agent mean the FDA could eventually approve the drug for treating human ailments, including cancer. This could save a considerable amount of time and money in developing new cancer-fighting drugs that are more affordable and accessible.
Dosing Fenbendazole for cancer
The limited studies suggest that Fenbendazole for humans is safe for consumption because it has low toxicity and a high safety margin. However, it is important to remember that the FDA has not approved Fenbendazole for use in humans.
The optimal dose of any medication and/or supplement is related to the individual characteristics of a patient’s overall health, current disease status, treatment history, and current treatment regimen.
In general, research has found that Fenbendazole for humans is well-tolerated with a single oral dose of 222 mg/per day (1 gram of Panacur®C) up to 444 mg/ per day (2 grams of Panacur®C). However, because human observations are limited, these should be considered general guidelines that may need to change depending on each individual’s health status and specific cancer. All benzimidazole medications, including FBZ and MBZ are absorbed best when a healthy fat snack/meal accompanies the dosage.
Consulting Healthcare Professionals Before Using FBZ or MBZ in Cancer Treatment
If you’re considering taking FBZ or MBZ for cancer treatment, it’s important to discuss your plans with a knowledgeable healthcare professional. These medications are not necessarily right for everyone, and your healthcare team must be aware of any new treatments you decide to try, you can speak with an integrative oncology nurse about your current cancer treatment plan to learn more about FBZ and MBZ for cancer. In addition, they can give you the latest information available about which product to use from this family of drugs and determine if taking one of them might be right for you.