By Duncan Walker BBC News Online

Clubbers have been warned about the dangers of GHB

It is widely known as a 'date rape' drug because of its use to knock victims unconscious in a string of sexual assaults.

But GHB's most common use by far is in Britain's clubs, where the soon to be illegal drug is also causing great concern for its sometimes profound effects on users.

Frank Warburton, director of drugs information charity DrugScope, said GHB's danger lies in its unpredictability and ability to send users into a coma or, in extreme cases, to kill them.

As one user succinctly described its effects to Plymouth University researchers:"(I) felt like I was drifting away in my own little bubble of consciousness, but my friends said I was puking and out of it."

'Similar to ecstasy'

GHB was developed as the anaesthetic gammahydroxybutrate, but it quickly became popular in clubs where 'liquid ecstasy' is the most popular among dozens of names for the drug.

It is also available as a powder and a pill and in extreme cases has been injected.

I think there's the feeling among clubbers that it does not have quite the same effect as ecstasy, but it's easy to get hold of DrugScope

"In some ways it's quite similar to ecstasy," says Mr Warburton.

"It's pleasant and it slows down body activity, if you take a small amount. It's not unlike a few drinks of alcohol."

He says it is difficult to know just how widespread its use in clubs actually is, although anecdotal evidence suggests its popularity has grown steadily in recent years.

Until now it has been readily and legally available for around �15 in many sex and drugs paraphernalia shops, helping it to divert some of the money that would otherwise be spent on ecstasy.

"I think there's the feeling among clubbers that it does not have quite the same effect as ecstasy, but it's easy to get hold of," Mr Warburton said.

Ibiza investigation

It is GHB's unpredictable effects and the fact it is "easy to make and easy to make badly" that has led DrugScope to back the decision to reclassify it as a Class C drug.

The situation is that the technology is changing all the time, people are trying things out all the time and new drugs are coming along all the time DrugScope

"Its results can be very unpredictable, with different people and it seems to be particularly problematic when taken with other drugs.

"The way it mixes with alcohol is particularly unpredictable."

The recipe for GHB has been on the internet for years, raising further fears about its safety.

At higher doses it can cause sleepiness, nausea, vomiting, muscle stiffness and confusion. Very high doses can lead to convulsions, coma and respiratory collapse.

Last year a BBC investigation on Ibiza found that as many as two British clubbers a night were ending up in hospital in a coma after taking GHB.

So far in the UK, only a handful of deaths caused by the drug have been reported every year.

But DrugScope believes many more go unnoticed because the victim will have combined it with other drugs.

New drugs

The decision to make GHB illegal could see its popularity among clubbers fall, DrugScope believes.

"The big question is whether making a drug illegal really stops the problem," Mr Warburton said.

"I think what it will mean is that its use relative to ecstasy will change."

The charity also warns that if GHB actually does start to disappear it will not mark an end to the popularity of new synthesised drugs and the need to continue providing accurate information.