WASHINGTON (Reuters) – The top U.S. consumer and trade regulator said on Tuesday it had warned three companies selling products infused with cannabidiol that it was illegal to advertise that such products could fight disease without providing credible scientific evidence.

In recent years, the chemical derived from the cannabis plant, commonly called CBD, has been touted as alleviating countless physical ailments.

The Federal Trade Commission said the three unidentified companies claimed, without providing substantiation, that CBD can treat more than two dozen conditions including cancer, Alzheimer’s, multiple sclerosis, schizophrenia, epilepsy, diabetes, psoriasis, and AIDS.

The companies, which sell oils, tinctures, capsules, gummies and creams, have 15 days to inform the FTC about how they will address the warning.

(Reporting by Lisa Lambert, Editing by Rosalba O’Brien)