The U.S. Food and Drug Administration sent warning letters Tuesday to 14 U.S.-based companies they say illegally sold more than 65 products that claim to prevent, diagnose, treat or cure cancer. The FDA says the products were marketed and sold without its approval.

The U.S. Food and Drug Administration sent warning letters Tuesday to 14 U.S.-based companies they say illegally sold more than 65 products that claim to prevent, diagnose, treat or cure cancer. The FDA says the products were marketed and sold without its approval.

The products cited in the warning letters include a variety of product types, such as pills, topical creams, ointments, oils, drops, syrups, teas and diagnostics (such as thermography devices). The FDA says the products make illegal, unproven claims about preventing, reversing or curing cancer.

“Consumers should not use these or similar unproven products because they may be unsafe and could prevent a person from seeking an appropriate and potentially life-saving cancer diagnosis or treatment,” said Douglas W. Stearn, director of the Office of Enforcement and Import Operations in the FDA’s Office of Regulatory Affairs. “We encourage people to remain vigilant whether online or in a store, and avoid purchasing products marketed to treat cancer without any proof they will work.

The FDA says people should consult a doctor about proper prevention, diagnosis and treatment of cancer.