Updated

Overzealous Australian tanners are risking their lives by using an illegal bronzing agent being sold over the Internet.

Nicknamed "the Barbie drug," Melanotan II promises to make users "tanned, thin and turned on," but doctors warned it could also prove to be fatal.

Initially popular with bodybuilders, the injectable drug is used by models, brides-to-be, actresses and others seeking an instant tan.

A 10mg vial of the synthetic hormone which increases the levels of melanin -- the skin's darker pigment -- can be bought online for AU$40 (US$42).

But Australian Medical Association board member Dr. Richard Kidd urged people to be cautious because the full extent of the drug's dangers remained untested.

It had been banned in Canada and throughout Europe after reported side effects including nausea, flushing, the darkening of freckles, high blood pressure, scarring, suppressed appetite, spontaneous erections and increased libido.

"People should not be messing with something that's unproven and theoretically increases the risk of skin cancers, particularly melanomas," Kidd said. "You might end up accidentally killing yourself."

Last year, the Therapeutic Goods Administration banned Australians from buying it overseas for personal use without a prescription.

But that did not stop sales and the drug is still freely promoted and available online to Australians.

A one-time user, bodybuilder Von Eirlys, 25, said she began using Melanotan II five years ago while working in the entertainment industry.

"I was working as a producer and saw all these models that had really nice tans," she said. "So one of the girls ordered it for me."

Click here to read more from The Daily Telegraph.