The US Food and Drug Administration (FDA) has sent warning letters to 14 US-based companies it accuses of illegally selling more than 65 products fraudulently claiming to prevent, diagnose, treat or cure cancer.

Products marketed and sold for human consumption or for pets, without FDA approval – usually on websites and social media platforms – include pills, topical creams, ointments, oils, drops, syrups, teas and diagnostics (such as thermography devices). The agency noted that the sellers make illegal, unproven claims regarding preventing, reversing or curing cancer, killing or inhibiting cancer cells or tumors.

In its correspondence, the FDA has requested responses from the 14 companies, asking them to explain how the violations will be corrected. Failure to do so promptly may result in legal action, including product seizure, injunction and/or criminal prosecution, it said.

Over the past decade, the US health watchdog said it has issued more than 90 warning letters in to companies marketing drugs and other products fraudulently claiming to cure cancer. Although many of the companies warned have stopped selling the products, the agency said “numerous unsafe and unapproved products continue to be sold directly to consumers due in part to the ease with which companies can move their marketing operations to new websites.”