In an effort to crack down on fraudulent remedies being sold over the Internet, the government has warned 25 companies to stop selling purported cancer cures that federal health officials say could disrupt legitimate treatment and even harm unsuspecting patients.

Food and Drug Administration officials, who announced Tuesday that they were investigating fake cancer remedies, said that warning letters had been sent to Internet sellers of 125 tablets, lotions and tonics that purported to cure cancer. The firms could have their products seized or face prosecution if they don’t stop marketing them within 15 days, the FDA said.

“Some products may present a direct safety hazard, while others could potentially interfere with medicines that a patient is already taking,” said David Elder, director of the FDA’s office of enforcement. He called the fraudulent sales “a cruel form of greed.”

Officials couldn’t point to any particular examples of harm to patients but said that one product, Black Salve, can burn away healthy skin. Officials also expressed concern that patients taking the unapproved products might avoid getting legitimate treatment.


The moves underscore the power of the Internet as a marketplace for fraudulent remedies. Similar problems in the pre-computer age led Congress to pass a 1938 law giving the FDA the power to bar sales of unproven products that could cause injury or death.

This year, authorities in Canada and Mexico and at the U.S. Federal Trade Commission sent warning letters to representatives of 112 websites that were being used to hawk unproven cancer treatments.