7 Healthcast: Injectable tanner prompts warnings

UNDATED (WHDH) -- An underground drug claims to create a long-lasting tan, shed pounds and even increase sex drive.

It's called Melanotan: an injection that's only sold online. It's a synthetic hormone that mimics a hormone in the human body which produces a tan.

When injected, Melanotan stimulates pigment cells, but there's a major issue with this underground drug:

"It's not regulated,” dermatologist Dr. Lisa Benest said. “It's not FDA approved and the studies aren't long-term enough."

The injection that stimulates pigment cells could simulate the same cells that turn cancerous.

The drug is banned in Australia and not approved in the US.