Fenbendazole Side Effects in Humans: What You Need to Know

Fenbendazole is a medication used to treat parasites, mainly in dogs. While the drug was created initially and primarily as a dewormer in animals, through animal research, it has also been found to have benefits for combating cancer cells. 

One such study found unexpected tumor growth inhibition in a group of mice treated with a combination of Fenbendazole and vitamins. As more studies emerge – some already published, some currently ongoing – a rapidly growing number of human patients are taking Fenbendazole to treat their cancer. 


Why cancer patients use Fenbendazole


Developing new drugs requires a lot of time, effort, and money, and generating a promising drug can take years. Fenbendazole is already an established drug showing promising results for human use with a very low level of toxicity. It has been shown to stabilize WT p53, provide moderate microtubule disruption, interfere with cancer cells’ glucose metabolism, and target cell cycle arrest. These factors have led to a decrease in cancer cells both in laboratory environments as well as in live subjects with minimal side effects and toxicity. In addition, Fenbendazole has been shown to kill cancerous cells and promote regression in cancer patients with large B-cell lymphoma that had metastasized, as well as other metastatic malignancies, bladder cancer, renal cell carcinoma, and more. 


Fenbendazole side effects in humans 

Although safety data exists for various animals, the safety and tolerability of Fenbendazole in humans for sustained periods of time have not been thoroughly studied yet. Nevertheless, many patients have decided not to wait for the lengthy bureaucratic process of scientific data to be published; they are following the protocol at their own risk. Most of these people report taking Fenbendazole without any side effects. 


According to a study available from the European Medicine Agency, doses up to 500 mg per person did not result in serious adverse effects. Moreover, single doses of up to 2,000 mg per person were reported to cause no serious adverse effects over the course of ten days. 


Side Effects of Fenbendazole Reported: 

Most people have NO side effects. The main complaints of the small group of people who did experience side effects were: 

* Mild diarrhea

* Mild stomach discomfort

* Elevated liver enzymes


Who May Be At Greater Risk of Side Effects?:

  • People who use Fenbendazole in high doses.
  • Use of medications and supplements that use the same pathways for metabolism as Fenbendazole
  • Those taking treatments/medications that increase liver enzymes  
  • One research suggests that those who are weak from chemotherapy may experience more side effects than those not receiving conventional cancer treatment, particularly in elevated liver enzymes. 


Minimizing Fenbendazole Side Effects

The best way to combat any side effects is by taking Fenbendazole as safely as possible. First and foremost, taking the correct dose for your individual needs is crucial, and also deciding which supplements to add (and just as important – which you shouldn’t be taking!). An integrative healthcare professional can discuss an advised protocol using your comprehensive medical information. This includes providing him/her with your lab reports, any medications you are currently taking, a treatment list, and medical history so that dosage, as well as safety risks, can be assessed and discussed. 

More on Our Blog

Best diet for cancer patients

Best Diet for Cancer Patients?

Navigating the tenuous relationship between food and cancer can be a daunting task. As a society, we are constantly being bombarded with

this treatment but not sure how to start? We can help

Searching for treatment and not sure where to start? We can help.

Subscribe to our newsletter

Get the latest news about natural treatments, alternative clinics and inspirational healing journeys. 

Looking for alternative cancer treatments?

Our advisors have helped hundreds of patients navigate their alternative options.

This website uses cookies to ensure you get the best experience.