The FDA says "magic power coffee" contains a chemical that can cause a dangerous drop in blood pressure.
It's similar to the active ingredient in Viagra, which is only available by prescription.
Magic power coffee is sold online as a natural herbal supplement, but regulators warn it could cause a dangerous interaction with other drugs.
So far there have been no reports of adverse interactions, but the FDA is warning customers to stop using it.
No response yet from the makers of the product.