"It’s like your brain is trying to crawl out of your head. It affects your whole body; headaches lasting three or four days, projectile vomiting. The side-effects of taking it are not worth the high.”

James (not his real name) discovered mephedrone through clubbing. For him it was the closest thing to ecstasy, one of the first substances he took when he started taking Drugs two decades ago during the 1980s rave scene.

“It came out last year and is very much like ecstasy used to be, so that is where the appeal came in, but the come-down from it is not like anything I have ever experienced,” says James.

The 36-year-old stopped taking the drug because of the violent side-effects, and he hopes others will be more cautious following the deaths of two teenagers in Scunthorpe last week which are thought to be linked to the ‘legal high’.

Mephedrone, also known as m-cat, meow meow and 4MMC, a plant fertiliser, is currently an unclassified drug popular among clubbers.

It is a stimulant-like substance and users say its effects usually last around two to three hours when it is taken orally.

Those who snort the white or yellowish powder can experience severe nosebleeds, vomiting blood and severe agitation. The drug can also cause a range of side-effects including insomnia, uncomfortable changes in body temperature, heart palpitations, short-term memory loss and teeth grinding.

Says James: “I have never seen anybody feel normal after they have come down off it. You feel like you are dying.”

James, who is a client at Project 6, a street drug and alcohol agency in Temple Street, Keighley, says the drug should be given the same classification as a Class A drug. “Without a doubt it should be a Class A drug. I can’t understand how it has got through,” he says. “People go on about heroin and crack and they are bad drugs, but this is up there with them for the after-effects.

“It is really scary. I have taken more or less every drug that is going, but I’ve never come across a drug that is so bad to come down from.”

Jon Royle, chief executive of Bradford’s Bridge Project drug treatment service, says mephedrone can be more sinister than other legal highs, as the short-term euphoria which users experience can quickly lead to addiction.

He called for the Government to take urgent action to prevent anyone taking advantage of the increased curiosity in the drug.

And he believes there should be an interim measure which the Government can use to temporarily ban these substances.

“We don’t know what the long-term impact of it may be. Our concern, as a treatment system, is that the law is just not set up to protect vulnerable people,” he says.

“At the moment there is a window of opportunity for unscrupulous business people to make lots of money and often at the expense of vulnerable young people.

“We would be expecting the Government to deal with this urgently in line with the professional scientific advice they get. Making the drug illegal will not stop people from using it and distributing it, but we do know if you prohibit the substance by law it cuts down on the distribution and use of it.”

Home Office Minister Alan Campbell says the Advisory Council on the Misuse of Drugs is considering mephedrone, and similar compounds, as a priority and is concerned about its potential danger.

“The Home Secretary has discussed this in person with the chairman. We will receive the advisory council’s advice next week and, subject to this advice, we will take immediate action,” he says.

“We are determined to act swiftly, but it is important we consider independent expert advice to stop dealers and organised criminals exploiting loopholes by simply switching to a different but similar compound.”

For more information, call Project 6 on (01535) 610180. The organisation operates a duty service every day between 1pm and 5pm, and no appointment is needed; or the Bridge Project on (01274) 723863, or visit bridge-bradford.org.uk.