The perfect tan in a bottle, but at what cost? The increasingly popular self-injecting "Barbie doll drug" Melanotan II is unregulated and, say doctors, could be dangerous.

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It is a treatment which promises to leave you tanned, thin and stimulated. Melanotan II is said to suppress your appetite and increases your libido while leaving you bronzed regardless of the season, writes Science Reporter Asha Tanna. But this synthetic hormone is an unlicensed drug so its quality, safety and efficacy has not been tested. This means it is illegal to sell in the UK - but not to buy online.

And this loophole means the illicit global trade of online pharmaceuticals is flooding the UK and the country's medicines regulator says the internet is "impossible to police" because these websites could be based anywhere in the world.

A website advert for tanning drug Melanotan 2.

Melanotan II can only be injected with needles. It is designed to stimulate the pigment cells in your body to produce more melanin, which gives you a tan. After several injections and exposure to the sun or a sun-bed to kickstart the process, your skin tone is claimed to change from the inside out.

There have been no long-term clinical trials and the side effects of this chemical are unknown. Doctors say it could potentially be very dangerous because it has the ability to change the shape and colour of moles. Reactions to the drug vary from person to person ranging from acute allergic reactions, to dizziness, sickness and acne. There is no way of knowing what is actually in the bottle or how it will react to other medicines.

Users inject Melanotan 2 to stimulate skin pigment creating a fake tan.

'I get a tan in one quick step'

And it is cheap to buy. The attraction, says Nichola Hill, a user from Hove says, "I get a tan in one quick and easy step. It's like anything, I do it in moderation."

Dr Patrick Bowler, a Harley Street dermatologist, told Channel 4 News that vanity is powerful force, which means even people afraid of needle overcome their fears. People, it seems, will do anything for the body beautiful. Following the explosion of non-surgical procedures on the cosmetic surgery market we appear to have become less squeamish about the use of needles. Women now pop out at lunchtime to get a Botox fix and anyone from hairdressers to dentists can administer the jab for you.

One woman from Sheffield, who wanted to remain anonymous, told us that she regularly used Melanotan 2 but hid it from her family. When I asked her why, she said they wouldn't understand "because only junkies inject".

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Needle safety

Self-injecting also highlights other concerns about needle safety issues. There is the risk of blood-borne diseases such as hepatitis and HIV. One national health and social care charity, the Crime Reductions Initiatives (CRI) told Channel 4 News that almost half of users at its needle exchanges in England and Wales are injecting image-enhancing drugs, not opiates like heroine. At Stockton CRI, on Teesside, staff have noticed a sharp increase in the use of Melanotan 2 over the last two years.

There are no national figures for Melanotan 2 use or steroids, weight loss drugs or any other image enhancing drug. Staff at CRI's needle exchange say the proportion of non-illegal drug users could be far higher because it remains unknown whether needles collected are shared with other users too.

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