By Jerry and Lisa Meloche, Pharm.D., Owners, Compounding Pharmacists
Ivermectin and mebendazole are medicines doctors have used for decades to treat parasites, like intestinal worms or head lice. Lately, there’s been a lot of talk—especially online—about whether these drugs might also help treat cancer.
Some early research in labs and animals has shown these medicines may slow cancer growth. But here’s the important part: there is no proof right now that they work in people with cancer. They are not FDA-approved for this use, and cancer experts warn against trying them without medical supervision.
What is Ivermectin?
Ivermectin is best known for treating certain parasitic infections in humans and animals.
• In the lab: Studies show it might slow the growth of cancer cells and make some tumors easier for the immune system to detect (PMC7505114). In mice with triple-negative breast cancer, combining ivermectin with certain immune drugs shrank tumors in some animals (City of Hope).
• In people: A small human study showed only one partial response and one case of stable disease out of eight patients. Most cancers continued to grow (Patient Power).
What is Mebendazole?
Mebendazole is another parasite medicine that works by blocking the ability of worms to absorb sugar, which they need to survive. Scientists have learned this same process can also affect cancer cells. In the lab and animals: Mebendazole has slowed the growth of cancers like brain tumors, pancreatic cancer, breast cancer, and melanoma in research studies (PMC8255490). In mice with pancreatic cancer, it helped stop tumors from spreading (Johns Hopkins Medicine).
Why This Is Not Yet a Cancer Treatment?
There’s a big difference between what happens in a lab dish or animal and what works in real patients. Many treatments look promising early but fail when tested in people.
The risks:
• Taking too much ivermectin can cause confusion, seizures, or even coma.
• Mebendazole, especially in high doses, can damage the liver or lower blood counts.
• Using animal (veterinary) versions of these medicines is dangerous and not the same as human prescription doses.
The concern: Cancer specialists say that people who try these drugs on their own may delay proven treatments like surgery, chemotherapy, or immunotherapy—and that delay can make the cancer harder to treat (AntiCancer Fund).
Research Is Still Needed
To know for sure if ivermectin or mebendazole can help treat cancer, researchers would need:
• Large, well-designed human studies.
• Careful dosing guidelines to avoid harmful side effects.
• Data on how these drugs might work alongside standard cancer treatments.
Until that happens, these medicines remain experimental for cancer.
What To Do If You’re Interested
If you or someone you know is considering a new or alternative cancer treatment:
1. Talk to your oncologist first. They can explain the latest research and help you weigh the risks and benefits.
2. Ask about clinical trials. If these medicines are being tested for your type of cancer, joining a trial is the safest way to try them.
3. Avoid self-medicating. Never use animal medicine or order from unreliable sources.
Ivermectin and mebendazole are safe and effective for certain parasitic infections, but right now, there’s no solid proof they work against cancer in people. The early lab and animal research is interesting, but until we have results from large human studies, these drugs should not replace standard cancer care.
Your best defense is to follow proven treatments, stay informed about new research, and work closely with your healthcare team to explore safe options for your care.
Creative Scripts Compounding Pharmacy custom builds medication, one patient at a time. We use the highest quality pharmaceutical-grade ingredients, state-of-the-art bases, equipment, and technology. Ongoing training on the latest techniques, advances in therapy, and regulations enables our pharmacists and technicians to provide the safest, most effective medications for you and your pets. In addition to compounded medications, we offer pharmaceutical-grade nutritional supplements, health advice, and hormone consultations. Creative Scripts specializes in veterinary compounding, dermatology, bio-identical hormone replacement therapy (BHRT), pain management, and more. Pharmacists Jerry and Lisa Meloche have served Naples and surrounding communities since 2005.
Creative Scripts Compounding Medicine
239-261-0050
600 Goodlette Road North #108
Naples, FL 34102
www.creativescripts.net
Sources:
• National Library of Medicine – Ivermectin and Cancer Research
• City of Hope – Drug Combo in Breast Cancer
• National Library of Medicine – Mebendazole Review
• Johns Hopkins Medicine – Mebendazole in Pancreatic Cancer
• AntiCancer Fund – Repurposed Drugs