Injections of a substance similar to a hormone naturally produced in the body appear to give people a tan with minimal sun exposure, new research suggests.

During the study, people were given ten daily injections of melanotan-1 (MT-1), a synthetic version of a hormone that triggers the production of the natural skin pigment melanin.

Moreover, the injections also appeared to offer some protection from sun-related skin damage, according to the report in the Archives of Dermatology.

"It took one-third or less of the normal amount of sunlight to get a very deep tan," study author Dr Robert T Dorr, a consultant to EpiTan, an Australian company that makes MT-1.

People who received MT-1 before exposing themselves to ultraviolet light or sunlight tended to tan more quickly than normal sunbathers, and showed fewer signs of sun-related damage to skin cells.

"Cosmetics is one thing, but if we can really protect people from sun damage...I think we'll have helped a lot of people," said the researcher, who is based at the University of Arizona in Tucson.

He added that researchers are currently investigating whether MT-1 can be administered as an implant that slowly releases the drug over time.

It may also one day be available as a lotion or in a pill, he noted.

The study was funded by the National Cancer Institute.

In an initial study, four people received 10 daily injections of MT-1 and four others received a placebo shot, followed by ultraviolet light.

In a second study, 12 people received 10 daily shots of MT-1 at an increased dose, including five days of ultraviolet exposure either during or after the shots.

A third group of eight people received the higher dose of MT-1 followed by regular sunlight exposure for 4 weeks.

In the first experiment, three out of four people became tanned, and developed nearly 50 per cent fewer sunburn cells than people who received a placebo shot.

Participants who received the higher dose developed a darker tan, and people who added MT-1 to sunlight exposure tanned faster than people who tried sunlight alone.

Dr Dorr said when the body is exposed to sun, surface skin cells become damaged and release the MT-1-like hormone, which triggers other cells to produce melanin.

MT-1, in contrast, bypasses this system by acting immediately on the melanin-producing cells, which "short circuits the need to get the damage," he said.

The drug differs from self-tanning products, Dr Dorr noted, which are merely colorants that produce something that does not protect against sunlight.
--Reuters