Patients who assume they can safely use OTC chelation products should be advised of a new FDA warning. The agency has told eight companies to stop selling chelation products that claim to treat Alzheimer’s disease, autism, and many other disorders. The agency is also advising consumers to avoid OTC chelation products that are marketed as disease prevention or treatment agents.

As the FDA notes, chelation involves the use of certain chemicals to remove heavy metals from the body. Some chelation products are marketed as dietary supplements, but federal regulators considers them to be unapproved drugs because they claim to treat, mitigate, prevent or diagnose disease.

The agency contends that even when used under medical supervision, chelation products can cause serious harm, including dehydration, kidney failure and death. The only FDA-approved chelating agents are available by prescription only and are approved for use in specific indications, such as lead poisoning and iron overload.