Exclusive: Police have warned that an increasing number of people in Scotland are taking �legal highs� bought online despite limited information about their potentially lethal side-effects.

Police have warned that an increasing number of people in Scotland are taking "legal highs" bought online despite limited information about their potentially lethal side-effects.

They have made a number of seizures at a time when there is growing concern about the widespread sale of unlicensed drugs and prescription medicine over the internet.

Several of the drugs have already been banned in other countries. The unclassified liquid party drug GBL is outlawed in the United States and Sweden but not in Britain, where it is available in some health food shops and over the internet.

Last week a coroner in Sussex recorded a verdict of misadventure into the death of cheerleader Hester Stewart, 21, a medical student who died after she took GBL. The coroner referred to young people playing "Russian roulette" with such substances.

The sale of drugs online has become a multi-billion pound industry, but experts warn it is entirely unregulated. A survey commissioned by the Royal Pharmaceutical Society of Great Britain found more than two million people in Britain regularly go online to buy prescription drugs such as the anti-depressant Prozac, the sex aid Viagra and Valium, which is used to treat anxiety.

The British Medical Association has expressed concern that buying even prescription drugs online does not offer the necessary safeguards. The latest research shows a quarter of GPs have treated patients for side effects caused by drugs bought on the internet.

Last week NHS Greater Glasgow and Clyde warned that women from all social backgrounds were injecting an unlicensed drug to give themselves an all-over tan. Melanotan is being bought online, despite reports that it causes side-effects including headaches, nausea and vomiting.

Detective Superintendent Willie MacColl, national drugs co-ordinator, Scottish Crime and Drug Enforcement Agency, said: "It is concerning that some people who would never risk taking more aspirin or paracetamol than the eight in 24 hours instructed on a label are willing to swallow tablets without knowing anything about their contents or side-effects.

"The police in Scotland have made a number of seizures of these different substances during investigations, but the small number of seizures does not necessarily reflect the prevalence or use of them in communities.

"People who use these substances need to be aware of the potentially harmful effects and it is important that parents and young people who are most likely to have questions have access to credible information.

"While not controlled, these substances do have mind-altering properties and as such hold inherent dangers."

Police say there is also an increase in dealers passing off "legal highs" as ecstasy. New figures obtained by The Herald show that in the past year, some 60% of ecstasy tablets analysed in Scotland were actually benzylpiperazine (BZP), which can cause acute psychosis and seizures.

Tayside Police last week warned there is growing evidence of widespread misuse of mephedrone, which is legal but has hallucinogenic properties. It is believed the drug is being passed off as ecstasy mixed with LSD, cocaine or ketamine.

Dave Liddell, head of the Scottish Drugs Forum, said: "For young people looking to take them there is an appeal because they are legal but there is an inherent risk. Even support services are not that familiar with how to deal with these drugs.

"The challenge for law enforcement is that they just keep changing the chemical derivatives."