Fenbendazole, originally designed to cure parasites, selectively blocks the synthesis of microtubules by binding to β-tubulin. This action stops the polymerization of tubulin dimers in parasite cells, leading to their death. Surprisingly, fenbendazole, along with other benzimidazoles, exhibits similar effects against tumor cells. Today, it is believed that fenbendazole kills cancer through three main mechanisms:
1. Apoptosis Induction
Fenbendazole’s anti-tumor effect is thought to occur through its interaction with β-tubulin, leading to cell cycle arrest and cytotoxicity. The inhibition of tubulin polymerization into microtubules by benzimidazole carbamates in both helminths and human tumor cells is well documented. (Source1, Source2)
2. Inhibition of Glucose Uptake in Cancer Cells
Malignant cells are known for their high glucose uptake, consuming glucose 200 times faster than ordinary cells due to aerobic glycolysis (Warburg effect). This can be observed in PET scans, where metabolically active sites, using more radioactive glucose, are typically cancerous tumors or sites of inflammation.
Fenbendazole limits cancer cell fueling by:
– Reducing glucose uptake.
– Decreasing the number of GLUT transporters (channels that transport glucose into cancer cells from the blood).
– Inhibiting the enzyme hexokinase 2, crucial for cancer cell survival. This enzyme helps tumors thrive by generating more sugar and accelerating lactic acidosis in the extracellular matrix. (Source1, Source2)
3. Reactivation of the p53 Gene
This mechanism is still controversial, and more studies are needed to confirm that fenbendazole causes this action. However, an increasing number of studies suggest that fenbendazole might enhance the activity of p53, the strongest tumor suppressor in our bodies.
Interestingly, elephants have 20 copies of the p53 gene in their genome, while humans have only one. This might explain why elephants get cancer less frequently than humans, despite having larger bodies, more cells, and a higher potential for genetic mutations. However, there is an increasing number of studies that confirm the fact that fenbendazole might truly increase the strongest tumor suppressor in our bodies – p53. (Source1, Source2)
Additional characteristics that make fenbendazole a remarkable anti-cancer strategy.
Cancer cells don’t develop resistance to fenbendazole.
What’s interesting, cancer cells cannot evade this de-wormer drug and adapt to its presence. This means that it can be taken constantly and remain effective. Unfortunately, advanced cancer can develop chemo-resistance to many chemotherapy and biological therapy medications, making them ineffective in time.
One of the main mechanisms of chemo-resistance in cancer cells is the adaptation of excreting the anti-cancer drugs to the outside via special drug efflux pumps called P-glycoproteins. Fenbendazole is not a target for p-glycoproteins, so it cannot be excreted out of cancer cells once it gets inside.
Therefore, the tumors don’t develop resistance against fenbendazole. It will still remain effective and kill cancer cells, which does not seem to be the case with a lot of chemotherapy drugs once chemo-resistance is developed. (Source)
Fenbendazole could sensitize tumors to radiotherapy.
The dog-dewormer could be a considerable option before and during radiation treatment. It sensitizes the cancer cells to the treatment in a similar way like chemotherapy agents from the taxane group. (Source)
References
Lacey, E. (1974). The benzimidazole anthelmintics—a review
Patel, K., & Bhuyan, R. (2021). Antitumor activity of albendazole against the human colorectal cancer cell line
Choi, S. H., Martinez, M. N., & Weatherly, L. M. (2018). Fenbendazole acts as a moderate microtubule destabilizing agent and causes cancer cell death by modulating multiple cellular pathways
Johnston, M. D., & Read, A. F. (2018). Repurposing anthelmintic drugs as cancer treatments: perspectives from evolutionary biology
Morris, G. M., & Keppler, D. (2019). The role of anthelmintic drugs in the treatment of cancer
Mukhopadhyay, T., Sasaki, J., Ramesh, R., & Roth, J. A. (2018). Antitumor effects of fenbendazole: A possible role of microtubule disruption
Lacey, E., & Morrell, A. (2013). Benzimidazoles in cancer therapy: repurposing anthelmintics for oncology
Pedersen, P. L. (2013). Hexokinase II: Cancer’s double-edged sword acting as both facilitator and gatekeeper of malignancy when bound to mitochondria
Is there any data at all suggesting fenbendazole could help with chronic inflammation? I’ve been in near constant pain since taking the 3 Covid jabs in 2021-22. Nothing else has helped, figured I’d ask!
There isn’t direct clinical data yet showing fenbendazole helps with post-vaccine or chronic inflammation, but many people have reported that it seems to reduce generalized inflammation and pain over time.
Fenbendazole works partly by lowering oxidative stress and inflammatory cytokines in animal studies- that’s one reason why some people notice better energy, less stiffness, or reduced nerve pain while on it. It’s not guaranteed, but there’s little downside to trying if your liver health is good and you take it responsibly.
Hello read where fenben may be used to help Rheumatoid Arthritis. Do you have a protocol to start at for male approx 185lbs.
Dear Rob,
Fenbendazole is sometimes mentioned as a supportive option for autoimmune conditions such as rheumatoid arthritis, although clinical data in humans remain very limited. In practice, people usually follow the same weight-based guidance that is used for oncology protocols. For an adult male weighing about 185 pounds (approximately 84 kilograms), the typical reference dose is 222 milligrams daily, taken as one capsule. The most common schedule cited in resources is six consecutive days of use followed by one day off, repeated weekly.
Fenbendazole is best taken with food containing some fat to improve absorption. Long-term users often add hepatic support, such as milk thistle or TUDCA, to lower the risk of liver stress. It is not advisable to exceed the commonly referenced doses, as higher exposures may increase the risk of adverse effects, especially on the liver. Regular monitoring of liver function is strongly recommended when fenbendazole is used for extended periods.
Bonjour, je suis actuellement suivi pour un adenocarcinome oesophagien TNM1 métastases au niveau du foie et des ganglions. Je fais de la chimiothérapie paclitaxel toutes les semaines, je voulais savoir au niveau des prises du fenbendazole 222mg comment le prendre, si je dois arreter 2 jours avant et 2 jours après cela fais 5 jours, sur 7 jours je ne dois en prendre que 2 jours ? Et surtout est ce que je peux le prendre avec mes métastases sur le foie.
Merci a vous
Hello, and thank you for your message.
Yes, you can take fenbendazole even with liver metastases, but it’s important to watch liver function closely, especially while on chemotherapy like paclitaxel, which is also processed through the liver.
The best results are shown when skipping 2 days, but if you take chemo so frequently, there is really a small window when fenbendazole can be utilized. If you really want to increase fenbendazole intake, avoid it 1 day before and 1 day after chemotherapy.
Where can you buy fenbendazole and ivermectin in the US ??
i know ivermectin was just approved for otc in arkansas
I was diagnosed in late 2023 with Stage 1 Chronic Lymphocytic Leukemia (CLL). I have a friend who had another type of cancer, who went from being sent home to die and is now cancer-free due to fenbendazole. I went downhill really quickly and by July of this year, I could barely walk. I had cellulitis, joint swelling, shortness of breath, etc. I was in pure pain 24/7 and nothing would heal. I started 1g a day of fenben AND I had read about a 28-day cleanse using Ivermectin. At about day 20, I was a new man. I cried one day because my pain was gone and I felt better than I had in years. At day 28 I stopped my Ivermectin. About 5-8 days later my severe body aches began to return. I now am using the combo again and at least the severe pain has subsided. I “plan” to return to GREAT by month’s end. That’s the background. I was wondering if people experience lows and highs similar to mine. One thing that I did do was my cheek was inflamed and I started an antibiotic. It brought down this swelling but it is slowly coming back. Any input is appreciated. Thank you!
Hello,
Thank you for sharing your experience. It is inspiring to hear about the progress you have made with Fenbendazole and Ivermectin, despite the initial challenges with chronic lymphocytic leukemia and the severe symptoms you were facing. Regarding the fluctuations in your symptoms, it is not uncommon for individuals using alternative protocols to experience periods of improvement followed by setbacks, particularly when stopping or adjusting treatments. The reintroduction of Ivermectin may have helped alleviate your pain, and discontinuing it could have caused some symptoms to return, as your body may still be adjusting to the absence of the treatment.
Given that you are experiencing positive results with this combination, it might be worth continuing. Additionally, as you mentioned the use of antibiotics for your inflamed cheek, it is possible that an underlying infection is contributing to the swelling, and the antibiotics may not have fully resolved it. Monitoring the inflammation and seeking advice from your physician could help prevent further complications.
You are taking the right approach by listening to your body and making necessary adjustments. Continue to track your symptoms and share your progress with a healthcare provider who can offer tailored advice. Wishing you continued success on your recovery journey.
How well is Fenben tolerated if the liver is compromised? Trying to come up with a plan for my brother who’s liver is now documented as “mostly compromised by metastasis”. He has been on an Opdoulag regiment for 5 months but his melanoma (internal) has spread like wildfire and is now totally systemic. Soft tissue, bones, etc… He is also Blood Type B-.
Dear Jane,
Fenbendazole is generally well tolerated, but extreme caution is necessary in cases of significant liver impairment, particularly due to metastases. Since Fenbendazole is metabolized by the liver, a compromised liver may struggle to process the drug, potentially causing increased stress or toxicity.
For individuals with extensive liver metastasis, it is critical to closely monitor liver function through enzyme levels (such as ALT, AST, and bilirubin) during treatment. If these enzymes rise significantly beyond a safe threshold, it could indicate the liver’s inability to handle the additional medication.
Considering your brother’s systemic melanoma and his ongoing Opdivo (nivolumab) therapy, which also impacts liver function, careful consideration is needed before adding Fenbendazole to his regimen.
Fenbendazole is often paired with liver-supporting supplements like milk thistle or NAC (N-acetylcysteine). Lastly, while his blood type (B-) doesn’t directly influence Fenbendazole metabolism, it may become relevant in other treatment aspects, such as immunotherapy or transfusions.
Is the dog version not recommended for human usage? I see this on Amazon: Panacur C Canine Dewormer (Fenbendazole), 4 Gram, 3 Count (Pack of 1), Red
I am 120 lbs. IF the dog version is good for HUMAN parasite cleanse (no idea if I have them of not, just want to feel better in general) how do I translate this version into 222 mg. If the dog version is NOT good for HUMAN, then I’ll reconsider the higher price for human version.
Hello, thank you for your question.
The dog version of fenbendazole, like Panacur C, is not officially recommended for human use, as it is formulated specifically for animals. However, some people do use it off-label for personal health reasons. If you decide to proceed with the dog version, it is crucial to be cautious with dosing.
For your weight (120 lbs), if you are aiming for a 222 mg dose:
– Each gram of Panacur C contains approximately 222 mg of fenbendazole.
– The 4-gram packet you mentioned would contain around 888 mg of fenbendazole total.
To achieve a 222 mg dose, you would use about 1 gram of the powder. It is important to measure carefully to avoid overdosing.
If you are concerned about safety or accuracy, you may want to consider the human version, which is more expensive but specifically formulated for human use.
My husband has stage 2 prostate cancer. He has type 2 diabetes and takes medications for it. He also takes medications like blood thinners and medication to prevent heart attacks. Is FenBen safe for him to take?
Hello Vicki,
Given your husband’s medical conditions and the various medications he is taking, it is crucial to approach fenbendazole use with caution. Fenbendazole is generally considered safe and well-tolerated, but its interactions with other medications, including those for diabetes, blood thinners, and heart attack prevention, are not well-documented.
For this reason, we cannot definitively say whether it is safe for your husband to take fenbendazole. Each person’s body can react differently to drug combinations. If you decide to proceed, it is advisable to start with lower doses and monitor how he feels. Additionally, try to space out the medications as much as possible.
I have a question. I have stage 4 esophageal cancer with many lymph nodes infected. My chemo routine is 3 days solid on a chemo pump every 14 days for the rest of my life; it’s awful. I have only learnt about FebBen last week. Can you make a recommendation of dose size and how many days to use.
Dear Sammy,
The Fenbendazole Dosage Guide, which can be found at https://www.fenbendazole.org/fenbendazole-information/fenbendazole-dosage-guide/, can help you figure out the right dosage.
To prevent any potential interactions, it is usually advised to stop taking fenbendazole two days before to, during, and after chemotherapy sessions. You may be able to stop chemotherapy and take fenbendazole consistently, depending on your condition.
Furthermore, milk thistle might be helpful because of its liver-protective qualities, which could lessen some of the negative effects of chemotherapy. The compound silymarin, which has anti-inflammatory and antioxidant qualities, is found in milk thistle.
We hope your treatment goes well and that you find strength in it.
I was recently diagnosed with MTSCC (kidney cancer). Is there anything for me to look for since the kidneys and liver process so much for our bodies? Is the protocol one 222 mg tablet per day 6 days per week and take one day off? I’m trying to wrap my head around all this.
Hello,
Fenbendazole has demonstrated promising results in treating various cancers, including kidney cancer. If you have not been diagnosed with stage 3 or higher chronic kidney disease (CKD), you may follow the fenbendazole protocol according to our dosing guide.
However, we cannot recommend a specific dose without knowing your body weight. You have selected the correct schedule; fenbendazole should be taken 6 days a week for cancer treatment. To find the appropriate dose and other essential information, please use our dose calculator, which you can access here:
https://www.fenbendazole.org/fenbendazole-information/fenbendazole-dosage-guide/
Additionally, you might consider adding supplements such as Milk Thistle, Vitamin D, and Curcumin to your protocol. While using fenbendazole, we strongly advise monitoring your well-being and regularly checking your blood tests. Pay particular attention to liver enzymes AST and ALT. As long as they are not elevated more than threefold, there is no reason to avoid or stop the protocol.
Thanks as always for all the information provided. This site is a great resource to learn about Fenbendazole. Appreciate it, many thanks
Hi, I was recently diagnosed with Well-differentiated neuroendocrine tumor (Grade 1), in Pancreas Body with abutment of the splenic artery. Size is 2cm. Normal appearing remainder of pancreas. MRI with Contrast confirmed no other organs or lymph nodes in area are impacted. By definition Grade 1 is “slow glowing, slow dividing, no evidence of spreading”. I began taking Fenbendazole a week ago. I’ve read that certain Chemo’s are only effective on fast growing and fast dividing tumors, and not effective on “slowing growing” type tumors. Is Fenbendazole effective on this type of Grade 1 neuroendocrine tumor, in reducing it, and/or totally removing it? Any information is appreciated. Thanks
Hello Jeff,
Recent evidence and preliminary studies suggest that fenbendazole has anticancer properties that can interfere with the growth and division of cancer cells. Although there is limited scientific data supporting its effectiveness in well-differentiated pancreatic neuroendocrine tumors, its mechanism of action is promising.
Fenbendazole is believed to disrupt microtubule function in cells, inhibit cell division, and cause cancer cell death. This mechanism is useful for treating various types of cancer cells, including slow-growing tumors.
When it comes to chemotherapy, conventional treatments often target fast-growing and rapidly dividing cancer cells. For slow-growing tumors, such as well-differentiated neuroendocrine tumors, alternative treatments or targeted therapies may be more effective. Based on how fenbendazole works, it could potentially act on tumor cells, leading to either complete tumor death or partial improvement.
Some of the referenced papers on albendazole testing in mice with peritoneal implants concluded that intra-peritoneal treatment was very effective, whereas oral administration was not. This is interesting to me as I have peritoneal tumors. Are you aware of any clinics, alternative or otherwise, that can administer antithelmics intraperitoneally?
Dear Susie,
The effectiveness of intraperitoneal albendazole in treating peritoneal tumors, as demonstrated in mouse studies, is indeed significant. However, finding clinics that offer this specific treatment can be challenging since intraperitoneal administration of anthelmintics like albendazole is not a common practice and is often considered experimental.
Currently, there are no widely accepted clinical guidelines or practices for the intraperitoneal administration of fenbendazole in humans. Nevertheless, ongoing research and emerging scientific evidence indicate that fenbendazole might be a promising candidate for cancer treatment, including peritoneal tumors.
While we recommend taking fenbendazole orally in the standard manner, the choice of how you administer the medication ultimately rests with you.
Hello,
I recently had a whipple surgery to remove a pancreas carcinoma. Before that I had 8 chemo cycles, and from the start I also used fenbendazol as addition to the chemo therapy. It seems to have worked, the tumor had shrunk so the surgery was succesfull. Since fenbendazol interacts with cell cycles, how long after the surgery can I take fenbendazol again? In about 3 weeks I will have chemo therapy again, the last four sessions. Greetings from the Netherlands.
Hello, Bardo, thank you for your comment and the great question!
You may wait at least a week – week and a half. Then if you feel okay, you may continue protocol. Also please keep in mind, that fenbendazole therapy and chemotherapy work best together if you make pauses with fenben at least 2 days prior and 2 days after a chemo round. This is because chemotherapy is particularly effective against quickly multiplying cells, although fenbendazole also inhibits cancer growth. So, if you want to achieve the optimum benefit from both therapies, we recommend taking brakes from fenbendazole before and a little after chemotherapy rounds.
I have aggressive prostate cancer.
I am on abiraterone currently.
Can I take Fenbendazole
Hello, Thomas.
Abiraterone is working by blocking the production of these hormones, abiraterone helps to slow down the progression of prostate cancer and may shrink tumors. It usually does not affect liver function. Still sometimes side effects of abiraterone may include fatigue, joint pain, high blood pressure, fluid retention, and LIVER FUNCTION abnormalities. So keep that in mind and make sure your liver enzymes are not too high. A blood test can show your liver enzyme results. We recommend tracking your enzymes at least every 1-2 months. It is important for individuals taking abiraterone to undergo regular monitoring of their liver function and other blood parameters to ensure the medication is well-tolerated.
d in the USA? Does it require a prescription? Where can fenbendazole be purchased in the USA? Does it require a prescription, or can it be purchased as a pet product?
Hello, Hale thank you for a question.
Typically, veterinary stores carry it for sale, though in limited quantities. Additionally, it is available for purchase on online shopping sites such as Amazon and at tractor supply. You may check most reputable sources in our “SUPPLIERS” section. https://www.fenbendazole.org/suppliers/
i am on diaylsis and have cirrohsis of liver I have just been diagnosed with adenocarcinoma cancer is fenbendazole safe for me to take
Hello, Danny. Thank you for contacting us!
Supplements and medications used during hemodialysis are critical. In dialysis patients, the drug dosage is usually lowered by 5-6 times. So we would propose you start with 40mg a day and then watch your liver enzymes. If everything is fine, only then consider gently increasing the amount.
See under Instructions
The treatment can be combined with the majority of chemotherapeutic drugs, radiation, or surgery.
Lovely just what I was searching for.Thanks to the author for taking his time on this one.
Hello my loved one! I wish to say that this article is awesome, great written and come with almost all vital infos. I would like to see extra posts like this .
4 months post kidney transplant and my husband has newly diagnosed stage 4 pancreatic cancer with spread to liver. How does this effect liver as oncologist stating his liver not strong enough to receive chemo?
Dear Dina,
Fenbendazole is processed in the liver, which could heighten the risk of liver-related side effects. Given your husband’s condition and the presence of cancer in his liver, it is crucial to approach Fenbendazole use with caution. Begin with doses lower than those recommended by standard protocols and gradually increase them. Simultaneously, closely monitor your husband’s health and regularly check his liver enzyme levels to ensure there are no adverse effects.
I STARTED HAVING CONVENTIONAL TREATMENT FOR HODGKINS, BRENTUXIMAB VEDOTIN, 4 MONTHS AGO I ALSO STARTED TAKING FENBENDAZOLE AT THE SAME TIME A CAT SCAN LAST WEEK SHOWED A 50% REDUCTION IN TUMOR SIZE DOSE 1/4 TEASPOON 6 DAYSON 1 DAY OFF I WEIGH 205 LBS
My wife has Stage 4 pancreatic adenocarcinoma. She was scheduled for Whipple surgery, but surgeon noted metastasis to peritoneum , so removed gall bladder and closed up . Now trying to decide best course . I favor Fenbendazole therapy ; she wants more chemo. Trying to convince her to try this unconventional approach , which is no doubt .held in disdain by the Medical Establishment. Question : She must suspend all chemo , allow a time to recover and then start Fenben therapy protocol . Is this correct ? Can’t have both going at once , I assume . So , what timeframe for recovery before starting Fenben therapy ?
Did you ever get a response about taking fenben with chemo?
Dear Leann,
We apologize for any delays in responding to comments. We strive to answer everyone as quickly as possible.
Regarding your question about using Fenbendazole alongside chemotherapy, we recommend pausing Fenbendazole 2 days before, during, and 2 days after your chemotherapy sessions.