U.S. regulators announced Tuesday that they were cracking down on unproven treatments being sold for sexually transmitted diseases (STDs).

The Food and Drug Administration and the Federal Trade Commission announced steps to remove products from the market that make “unproven claims to treat, cure, and prevent” STDS.

The FDA and FTC said they had sent “multiple letters” to companies selling the products warning them that the products violate federal law.

The products, including Medavir, Herpaflor, Viruxo, C-Cure and Never An Outbreak, are sold online and in retail stores and claim to treat a range of STDs, including herpes, chlamydia, genital warts, HIV and AIDS. But they have not been evaluated by the FDA for safety and effectiveness, the agencies said.

“These products are dangerous because they are targeted to patients with serious conditions, where treatment options proven to be safe and effective are available,” said Deborah M. Autor, director of the Office of Compliance in FDA’s Center for Drug Evaluation and Research in a statement. “Consumers who buy these products may not seek the medical attention they need and could spread infections to sexual partners.”

The products are illegal under the federal Food, Drug and Cosmetic Act and the Federal Trade Commission Act, the agencies said.

“These companies are on notice that advertising health benefits that are not supported by rigorous scientific evidence violates the FTC Act,” said David Vladeck, director of the FTC’s Bureau of Consumer Protection. “They also should know that health scams that endanger public health will not be tolerated.”

The companies have 15 days to notify the FDA and FTC of the steps they have taken to “correct the violations cited. Failure to do so may result in legal action, including seizure and injunction, or criminal prosecution.”

Debbie Birnkrant of the FDA explains in this video:

This post has been updated since it was first published.