Fenbendazole Side Effects in Humans: What You Need to Know

Fenbendazole is a medication used to treat parasites, mainly in dogs. The drug was initially developed to deworm animals. Animal research revealed additional benefits in combating cancer cells.

One such study found unexpected tumor growth inhibition in a group of mice treated with a combination of Fenbendazole and vitamins.

More and more human patients are taking Fenbendazole to treat their cancer, as an increasing number of published and ongoing studies continue to emerge. 


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.

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. 

The most recent studies (published 2023) have also shown that Fenbendazole can potentially be used to treat pancreatic, ovarian, and colorectal cancer. 


Fenbendazole side effects in humans 


As previously mentioned, Fenbendazole is commonly used as a veterinary medicine. While 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.

However, despite the lack of scientific data, many patients have decided to try Fenbendazole on their own, as they don’t want to wait for the lengthy bureaucratic process of scientific data to be published. They are willing to take the risk and follow the protocol themselves.

Interestingly, most of these individuals report taking Fenbendazole without any side effects. Nonetheless, it’s important to note that individual results may vary, and taking Fenbendazole without consulting a healthcare professional first can be dangerous.

According to a study available from the European Medicine Agency, doses up to 500 mg per person did not result in serious adverse effects. This suggests that Fenbendazole may be safe for use in humans at this dose level. Additionally, single doses of up to 2,000 mg per person were reported to cause no serious adverse effects over 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.
  • People taking medications or supplements that use the same pathways as Fenbendazole.
  • Those taking treatments/medications that increase liver enzymes  
  • People who are undergoing chemotherapy may experience more side effects. These may include high liver enzyme levels. 


Minimizing Fenbendazole Side Effects


Minimizing the side effects of Fenbendazole is essential to ensure the safe use of the drug in humans.

> One of the most important ways to minimize side effects is by taking the correct dose for your needs. The dosage of Fenbendazole for humans can vary depending on factors such weight, medications you take, and the type of cancer being treated. It is recommended that you work with a healthcare professional who has experience with Fenbendazole and its use in cancer treatment.

> You should always buy reputable brands such as Safe Guard.

> To overcome limited absorption by our digestive system’s tract itself, it’s recommended you take fenbendazole with food: adding the powder right into your meal drastically improves its ability to enter circulation

> Another important factor to consider when using Fenbendazole is the addition of supplements. While some supplements can enhance the effectiveness of Fenbendazole, others may interact negatively with the drug, causing side effects or reducing its efficacy. Therefore, it is crucial to discuss any supplements you are taking or considering taking with your healthcare professional to ensure their safety and efficacy.


Safe Protocol Using Fenbendazole 

Working with an integrative healthcare professional is an excellent way to develop a protocol that works best for your individual needs. Your healthcare provider will take a comprehensive medical history and review your current medications, lab reports, and treatment list to assess dosage and safety risks. This allows for a more personalized approach to the use of Fenbendazole in cancer treatment, reducing the risk of side effects and ensuring the best possible outcome.


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