Repurposing Anthelmintics for Cancer Treatment: A Fenbendazole-Based Protocol with Ivermectin and Mebendazole (2025)

Introduction

Cancer remains one of the most challenging diseases to treat, despite advances in targeted therapies, immunotherapy, and precision medicine. As patients seek alternative and complementary treatments, drug repurposing has gained significant attention. Among these repurposed drugs, fenbendazole (FBZ)—a broad-spectrum anthelmintic commonly used in veterinary medicine—has emerged as a potential anticancer agent. Initially anecdotal, reports of its effectiveness in various cancer types have sparked interest in its mechanisms and possible therapeutic role.

Several patients, including Joe Tippens, have publicly shared their experiences of tumor regression and disease stabilization after integrating fenbendazole into their cancer treatment regimens. Encouraged by these cases, further investigations have explored its microtubule-disrupting, apoptosis-inducing, and glucose-metabolism-inhibiting properties, which resemble the mechanisms of established chemotherapeutic agents.

Beyond fenbendazole, other anthelmintic drugs such as ivermectin and mebendazole have also demonstrated anticancer potential in preclinical studies. Ivermectin has been shown to inhibit cancer cell proliferation and modulate immune responses, while mebendazole disrupts microtubule formation and inhibits angiogenesis. Given their overlapping and potentially synergistic mechanisms, a combination approach has been proposed to enhance efficacy and improve patient outcomes.

This article examines the emerging evidence surrounding fenbendazole, ivermectin, and mebendazole as potential cancer treatments. We analyze patient-reported case studies, proposed mechanisms of action, and a structured treatment protocol based on available data. While the findings are promising, the lack of large-scale clinical trials necessitates further research. Patients considering these treatments should consult their healthcare providers before integrating them into their regimen.

1. Core Anthelmintic Drugs

(A) Fenbendazole (FBZ)

• Dosage: 222 mg (1 gram of 10% fenbendazole) daily

• Schedule: 3–6 days per week (commonly Mon-Fri, with weekends off)

• Proposed Mechanism:

1. Disrupts microtubules, inhibiting cancer cell division (major mechanism) [1]
2. Increases p53 tumor suppressor levels (major) [2] 
3. Blocks glucose transport and impairs glucose utilization by cancer cells (major)
4. induces cell cycle (G2/M) arrest
5. inhibits cancer cell viability (mTOR)
6. inhibits cancer cell migration and invasion (EMT pathway)
7. induces apoptosis
8. induces autophagy
9. induces pyroptosis and necrosis
10. induces differentiation and senescence
11. inhibits tumor angiogenesis
12. reduces colony formation and inhibits stem-ness in cancer cells
13. inhibits drug resistance and sensitizes cells to conventional chemo as well as radiation therapy.

Reported Effective for:
✔ Lung Cancer (NSCLC, SCLC)
✔ Colorectal Cancer
✔ Pancreatic Cancer
✔ Breast Cancer
✔ Prostate Cancer
✔ Brain Tumors (Glioblastoma, Astrocytoma)

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(B) Ivermectin (IVM)

• Dosage: 12–24 mg per day (based on weight: ~0.2 mg/kg)

• Schedule: 2–3 times per week

• Proposed Mechanism [3, 4]:

  1. Inhibit Wnt pathway
  2. Inhibit Akt/mTOR pathway 
  3. Inhibit MAPK pathway 
  4. Inhibit YAP1 protein
  5. Inhibit PAK1 protein 
  6. Inhibit HSP27 
  7. Induce mitochondrial dysfunction 
  8. Inhibit cancer stem cells 
  9. Inhibit p-glycoproteinand MDR protein 
  10. Activate P2 × 7 receptor 
  11. Inhibit SIN3 domain 
  12. Inhibit DDX23 helicase 
  13. Activate chloride channels 
  14. Increase TFE3 Activity 
  15. Inhibit KPNB1 protein 

Reported Effective for:
✔ Lung Cancer
✔ Breast Cancer
✔ Ovarian Cancer
✔ Leukemia & Lymphoma

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(C) Mebendazole (MBZ)

• Dosage: 100 mg–200 mg per day

• Schedule: Daily or 4–5 times per week

• Proposed Mechanism (5):

1. Mebendazole and Fenbendazole are very structurally similar and generally just as effective in cancer, in both in vitro and in vivo models (Song, et al., 2022). 
2. Benzimidazoles have anticancer effects through microtubule polymerization, induction of apoptosis, cell cycle arrest (G2/M), anti-angiogenesis, blocking glucose (Son, et al., 2020) and glutamine pathways (Mukherjee, et al., 2023). 
3. Apoptosis is induced by mitochondrial injury and mediated by p53 expression (Mukhopadhyay, et al., 2002; Park, et al., 2022)
4. Benzimidazoles also target Cancer Stem Cells and metastases (Son, et al., 2020; Song, et al., 2022) and, thus, the chemoresistant (cisplatin) cancer cells (Huang, et al., 2021).
5. Mebendazole was more potent against gastric cancer cell lines than other well-known chemotherapeutic drugs (5-fluorouracil, oxaliplatin, gemcitabine, irinotecan, paclitaxel, cisplatin, etoposide and doxorubicin) in vitro (Pinto, et al., 2015). Whereas Mebendazole leads to significantly prolonged survival compared to standard chemotherapy (temozolomide) for glioblastoma multiforme in vivo (Bai, et al., 2011).

Reported Effective for:

• Brain Tumors (Glioblastoma, Astrocytoma, Medulloblastoma)
• Colorectal Cancer
• Liver Cancer
• Melanoma
• Gastric Cancer (Stomach Cancer)

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2. Supporting Supplements

Several case reports and studies suggest that adding these may enhance effectiveness:

• Curcumin (Turmeric Extract) – 600-1200 mg daily (Anti-inflammatory, enhances apoptosis) [6]

• Vitamin D3 – 5000-10,000 IU daily (Immune system modulation, anti-cancer properties) [7]

• CBD Oil – Variable dose (Potential intracellular vesicle formation and cell death) [8]
  

• Zinc & Selenium – Immune support and DNA repair properties [9]

• Vitamin E (Mixed Tocotrienols and Tocopherols) – 400-800 IU daily (Antioxidant, supports cellular health) 

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3. Diet & Lifestyle Recommendations

• Ketogenic or Low-Carb Diet (Reduces glucose availability to cancer cells) [10, 12]

• Intermittent Fasting (May enhance autophagy and apoptosis) [11]

• Exercise & Stress Reduction (Supports immune function and overall well-being)

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4. Treatment Monitoring & Adjustments

• Regular imaging scans (CT, MRI, PET scans) and blood tests to track tumor response.

• Some patients adjusted drug frequency based on tolerance or progress.

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5. Precautions & Medical Considerations

• Drug Interactions:

  • Ivermectin & Mebendazole may interact with chemotherapy or immunotherapy.

  • Mebendazole may increase liver enzyme levels; periodic liver function tests are recommended [LiverTox].

• Long-Term Safety:

  • No long-term human studies exist for fenbendazole in cancer treatment.

  • Patients should consult their oncologists before using this protocol.

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6. Case Reports and Anecdotal Evidence

Lung Cancer (NSCLC, SCLC)

• Joe Tippens' Case: Diagnosed with Stage 4 small-cell lung cancer, complete remission after using fenbendazole + supplements [13].

• 62-year-old male (NSCLC): Tumor shrinkage confirmed via CT scans after integrating fenbendazole + ivermectin. [14]

Breast Cancer

• 69-year-old woman (Stage 4, liver/bone metastases): CEA tumor markers dropped 43% after adding fenbendazole. [14].

• 51-year-old patient (HER2+): Tumor size reduction with fenbendazole + chemotherapy. [14]

Pancreatic Cancer

• Stage 4 patient (diagnosed Aug 2023): Cancer marker dropped from 100,000 to 35,000 in 3 months on fenbendazole + mebendazole. [14]

Colorectal Cancer

• Stage 4 patient: Tumor reduced significantly, improved quality of life with fenbendazole + ketogenic diet. [14]

Glioblastoma & Brain Tumors

• Man with glioblastoma: Tumor progression halted for 6 months using fenbendazole + mebendazole. [14]

Ovarian & Prostate Cancer

• Ovarian cancer (advanced, high CA-125 levels): Substantial tumor shrinkage after integrating fenbendazole + ivermectin.

• Prostate cancer (45-year-old male): PSA levels dropped, tumor size reduced after fenbendazole + supplements.

Liver Cancer & Melanoma

• 72-year-old male (late-stage liver cancer): Improved liver function, tumor stabilization with fenbendazole + ivermectin.

• Metastatic melanoma patient: Lesion reduction, prolonged progression-free survival after adding fenbendazole.

Read More: Compilation of patient success stories with fenbendazole.

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Conclusion

This multi-drug repurposing protocol (Fenbendazole + Ivermectin + Mebendazole) is based on anecdotal evidence, preclinical studies, and patient reports. Critics may dismiss them as pseudoscience or low-quality data. However, these testimonials could represent just the tip of the iceberg—an emerging frontier that science is only beginning to explore.

For a more comprehensive understanding, it's worth looking into additional research studies and clinical trials. As always, consult with your healthcare provider(s) before making any treatment decisions, as close monitoring and personalised care are essential.

References:

1. Dogra et al. (2018) - Fenbendazole disrupts microtubules in cancer cells. Scientific Reports.

2. Park et al. (2022) - Anti-cancer effects of fenbendazole on 5-fluorouracil-resistant colorectal cancer cells. Korean J Physiol Pharmacol.

3. Juarez et al. (2018) - The multitargeted drug ivermectin: from an antiparasitic agent to a repositioned cancer drug. Am J Cancer Research.

4. Mingyang Tang et al. (2021) - Ivermectin, a potential anticancer drug derived from an antiparasitic drug. Pharmacol Research.

5. Baghli et al. (2024) - Targeting the Mitochondrial-Stem Cell Connection in Cancer Treatment: A Hybrid Orthomolecular Protocol. Journal of Orthomolecular Medicine.
6. Aggarwal et al. (2018) - Curcumin’s role in apoptosis and cancer therapy. Cancer Prevention Research.
7. Seraphine et al. (2023) - The impact of vitamin D on cancer: A mini review. The Journal of Steroid Biochemistry and Molecular Biology.
8. Hwang et al. (2023) - Cell death induction and intracellular vesicle formation in human colorectal cancer cells treated with Δ9-Tetrahydrocannabinol. Genes Genomics.
9. Yildiz etal. (2019) - Effect of the Interaction Between Selenium and Zinc on DNA Repair in Association With Cancer Prevention.  J Cancer Prevention. 
10. Seyfried et al. (2020) - Consideration of Ketogenic Metabolic Therapy as a Complementary or Alternative Approach for Managing Breast Cancer. Frontiers in Nutrition.
11. Tiwari et al. (2022) - Effect of fasting on cancer: A narrative review of scientific evidence. Cancer Science.
12. Seyfried et al. (2021) - Ketogenic Metabolic Therapy, Without Chemo or Radiation, for the Long-Term Management of IDH1-Mutant Glioblastoma: An 80-Month Follow-Up Case Report. Frontiers in Nutrition.

13. Joe Tippens’ Story. (2021) - Reported remission with fenbendazole. 

14. OneDayMD.com. (2025) - Compilation of patient success stories with fenbendazole.

15. OneDayMD.com. (2025) - Mebendazole vs fenbendazole for cancer

16. OneDayMD.com. (2025) - Ivermectin vs Fenbendazole for Cancer

17. OneDayMD.com. (2025) - Best Ivermectin Dosage for Humans with Cancer or Different Cancer Types

18. OneDayMD.com. (2025) - Top 18 Repurposed Drugs and Metabolic Interventions to Control Cancer

19. OneDayMD.com. (2025) - Ivermectin and Fenbendazole: Treating Turbo Cancer

20. OneDayMD.com. (2025) - Fenbendazole: Questions Answered, Things to Know, Useful Tips