Mayo Clinic on use of ivermectin or other dewormers to treat cancer

Mayo Clinic does not currently recommend using ivermectin or other dewormers as a cancer treatment unless they are part of a research study called a clinical trial.

You may have heard about these medicines online, on social media or from friends. They also are called antiparasite medicines.

Cancer and cancer information are complex. It is common to feel anxious and overwhelmed. And with so much information out there, it can be hard to tell what is true.

Here's what Mayo Clinic experts want you to know

• There is no evidence that antiparasite medicines treat cancer in the human body. Early studies show possible benefit in lab cells or animals but not in people. Most new drugs that seem to work in lab or animal studies do not end up working or being safe in humans. So at this time, more research is needed to understand how these medicines affect people.
• Doses suggested online can be dangerous. Ivermectin and another medicine called mebendazole are approved by the Food and Drug Administration (FDA) for human use in the U.S., but only as a limited-time treatment for parasites. They are not meant to be taken daily or long-term. The antiparasite medicine fenbendazole is only approved for animals. So there is no research yet on whether taking any of these long-term is safe for people.
• Side effects are possible. These medicines can cause upset stomach, sore muscles or joints, and dizziness. You may need extra tests to check on side effects. Serious side effects — such as seizures and confusion — have sent some people to the hospital. The medicines also can affect liver test results and cause serious liver damage.
• These medicines may delay standard treatment. A delay in standard treatment in order to use ivermectin, dewormers or other alternative therapies can allow cancer to grow or spread. Sometimes, waiting too long to get standard treatment can lower the chances of survival.

Your healthcare team understands

When you have cancer, you may want to try everything you can. That's understandable. Mayo Clinic is here to help you make the best treatment decisions for your care.

• Standard treatments have been tested in many people. Treatments such as surgery, chemotherapy and radiation therapy are not perfect. But they have been studied in thousands of people, and they have helped millions of people survive.
• You have choices. You may have options when it comes to standard treatments. You also can use safe, supportive therapies along with them. These may include acupuncture, nutrition support, reiki or other integrative therapies. Talk with your care team about what is best for you. And ask about integrative therapies if you are interested.
• Clinical trials are the safest way to explore new treatments. A clinical trial is a research study that looks at the safety of a treatment and how well it works in people. Some clinical trials are testing possible new cancer treatments, including ivermectin and other dewormers. These studies include strict monitoring. This makes them safer than taking something on your own.

When you choose well-studied therapies, you give yourself the best chance of successful treatment. Your care team supports you with understanding and with the best and safest tools medicine can offer.

Experiences and information shared by members on the Mayo Clinic Connect are not a substitute for professional medical advice, diagnosis or treatment. Never disregard professional medical advice or delay in seeking it because of something you have read on the community. Talk to your oncologist if you are interested in learning more.

Related information

• Separating fact from fiction: repurposed drugs in cancer treatment
• Can online health information be trusted? Here’s how to tell
• Community Guidelines for Mayo Clinic Connect