Ivermectin and Mebendazole for Thyroid Cancer? A Case Series of 3 Case Reports (January 2026)

Introduction

In recent years, interest has surged around repurposing established antiparasitic drugs as potential adjuncts in oncology. Among these, ivermectin and mebendazole—long-used to treat parasitic infections—have been spotlighted for their purported anticancer properties, driven largely by anecdotal case reports and limited preclinical research. On January 7, 2026, Dr William Makis published a case report describing a 67-year-old female with stage IV thyroid cancer who was treated with a high-dose ivermectin and mebendazole regimen and experienced a reported dramatic response.

The case report compilation presented below, while intriguing, underscores the persistent gap between anecdotal clinical observations and rigorous, controlled clinical evidence. Notably, preclinical studies have demonstrated that mebendazole can inhibit thyroid cancer cell proliferation and metastasis in laboratory models, providing biologically plausible mechanisms that warrant further systematic investigation. 

Ivermectin and Mebendazole for Thyroid Cancer: Case Presentations

Case 3 - 2026: 67 year old Ontario woman with Stage 4 Thyroid Cancer metastatic to bone

Reported by Dr William Makis on X.com (Jan 2026):

IVERMECTIN and MEBENDAZOLE Testimonial - 67 year old Ontario woman with Stage 4 Thyroid Cancer metastatic to bone reports after 7 months with a miraculous PET/CT Scan!

No one has success with Stage 4 Thyroid Cancer. STORY: 67 year old Ontario woman with Stage 4 Thyroid Cancer metastatic to bone In March 2025 she started: Ivermectin 1.5mg/kg/day 

Mebendazole 1500mg/day Results after 7 months: "Interval complete metabolic response involving previously seen metabolically active lesions in the anterior neck, superior mediastinum and bilateral lungs" "Near complete response involving L5 vertebral body lesion" "Previously seen metabolic activity in the right shoulder/deltoid has resolved".

KEY POINTS: There is published literature on aggressive Thyroid Cancers responding to Mebendazole in particular (2020 Williamson et al).

Case 2: Follicular Thyroid Cancer

Reported by Dr William Makis on X/Twitter (Dec 2024):

IVERMECTIN Testimonial with Follicular Thyroid Cancer - sometimes less is more - when a slow growing tumor disappears with a low dose of Ivermectin alone! 

Sometimes the shortest stories can be the most impactful. Follicular thyroid cancer patient with a stable biopsy confirmed tumor. 

Took 12mg of Ivermectin, 5 days a week, for about 5 months and the tumor disappeared. Nothing more. No Fenbendazole. No Mebendazole. Simple, yet effective 

This is anecdotal evidence in support of a cancer prophylaxis dose of 12mg for Ivermectin (it seems even at that low dose, Ivermectin exerts a substantial anti-cancer effect). 

There is the additional possibility that benign tumors or very slowly growing low grade malignant tumors can also be sufficiently and successfully treated with a low dose of Ivermectin.

Case 1: Thyroid Cancer and Ivermectin

Dr William Makis updated the case (Dec 2024):

Alberto reached out to me about 6 months ago asking about Thyroid Cancer and Ivermectin. 

There isn't any research on Ivermectin use in thyroid cancer but Ivermectin has very broad anti-cancer activity against many cancers so I suggested using it. 

"thyroid biopsy and pathology reported papillary thyroid cancer" 

"You recommended me to take Ivermectin in high doses, 3 to 4 times more than the normal antiparasitic dose and take it every day before surgery. I took Ivermectin 0.6% 3 drops per kilo of weight for 22 days, I had a total thyroidectomy and four lymph nodes, everything went to pathology and oh surprise the cancer had disappeared"

 
6 months later...

 

"thanks to you I overcame thyroid cancer" 

So we now have anecdotal evidence for the use of Ivermectin in Papillary Thyroid Cancer.

Dr William Makis reported an IVERMECTIN and thyroid cancer testimonial (Oct 2024):

Thyroid Cancer disappears after short term high dose Ivermectin Therapy. Another Ivermectin success story.

There is very little preclinical research on Ivermectin and Thyroid Cancer so these types of experiences are going to be crucial in developing an understanding of the role of Ivermectin in Thyroid Cancer.

Conclusion

The case series presented highlights striking individual outcomes involving ivermectin and mebendazole in patients with thyroid cancer. However, these reports remain anecdotal and are not supported by controlled clinical trials. While mebendazole has demonstrated anticancer activity in preclinical thyroid cancer models, and ivermectin shows broad anticancer effects in vitro, neither drug is approved for cancer treatment, and evidence from rigorous human studies is lacking. As such, these case reports should be interpreted with caution. 

Well-designed clinical research is essential to determine whether these agents have a safe and effective role in thyroid cancer treatment beyond isolated case experiences. Until such data are available, patients and clinicians should continue to rely on established, evidence-based therapies, while any off-label drug use should be carefully considered within structured clinical trials—including N-of-1 designs—or under “right-to-try” frameworks with appropriate specialist oversight.