Also known as E, doves, MDMA, MDA, X.

One of the most widely used illicit drugs in the UK, E is now the most popular party drug on the club scene. It is an amphetamine-based drug which has mildly hallucinogenic effects. It is commonly used at nightclubs and raves because it can greatly enhance mood, energy levels, feelings of empathy with others, perception of colour and music. In the UK, ecstasy is an illegal Class A drug. Dealing carries a maximum life prison sentence and unlimited fine, and possession up to seven years in prison and a £5,000 fine.

The drug is sold in tablet form and can be bought for between £2 - £5. MDMA powder can sometimes also be bought for approx. £20-40 a gram. After about 30 to 45 minutes the drug gives an intense high, which may last for several hours. Because the body becomes tolerant of the drug, people may end up taking larger quantities to induce similar feelings of euphoria.

As with all recreational drugs, it is difficult to know what the ecstasy tablet you are using really contains. The doses found in street drugs are not controlled, and the ecstasy pill you buy might contain much larger quantities of the drug. Often ecstasy will have been cut with other substances which could be poisonous, or with other drugs, usually amphetamines or LSD, but occasionally heroin.

In the short-term, ecstasy can cause dehydration, headache, chills, eye twitching, jaw clenching, blurred vision, nausea and vomiting, and like many drugs taken to get high, is commonly accompanied by a low period or come-down. Long-term use has been linked to poor mental health, depression, psychotic episodes and memory problems.

People can have an allergic reaction to the drug, which can be fatal (though deaths related to ecstasy are very rare relative to the extent of its consumption). The drug has also been associated with heart and lung problems, dramatic increases in body temperature, kidney failure, and liver damage. The potential liver toxicities of ecstasy and other recreational drugs are of particular concern to people with HIV as liver damage can make you very ill in its own right, and stop the body from processing anti-HIV drugs properly.

Ecstasy has been linked to unsafe sex by a number of studies of sexual behaviour amongst gay men. Some ecstasy users may argue that since the drug relaxes blood vessels, making erections difficult to maintain, unsafe sexual practices are being reduced by the drug. However, this does not prevent an ecstasy user being the receptive partner. Furthermore, the anti-impotency drug Viagra, which became more widely available in the UK in 1998, is being combined with ecstasy to enhance the atmosphere of sexual risk-taking that is occurring amongst club-going gay men in the UK.

People who are taking prescribed medication such as Prozac or other selective serotonin reuptake inhibitors should avoid ecstasy, since interactions between the two drugs can have unpleasant effects. Ecstasy is commonly combined with LSD, speed and/or ketamine in a sequence designed to extend and deepen the experience. LSD tends to add visual intensity but can also lead to feelings of paranoia, disorientation and distress if taken in a high dose (see LSD) or in an already unsettled state of mind.

Speed tends to lengthen the duration of the effect, and some forms of E have a high content of MDA, a chemical which is on the amphetamine end of the hallucinogen-amphetamine scale. Ketamine (see below) can cause radical disorientation and a feeling of being cut off from the surrounding world, but can also intensify the visual/hallucinogenic experience. People coming down from E may take sleeping tablets, tranquillisers or Prozac to help them chill out and to assist sleep. Some people report feelings of depression some days after use, perhaps because the drug disrupts the long-term balance of serotonin, a brain chemical which influences mood.

There have been concerns expressed that long-term ecstasy use cause brain damage, based on research carried out in animals and tests in small numbers of humans. So far this research has produced conflicting results.

Women with a history of genitourinary tract infection should use with caution, since women who use it seem to suffer from GU infections more frequently than others. Nothing is known about the effects of the drug on the unborn child.

People taking protease inhibitors, particularly ones boosted with ritonavir, need to be especially careful taking ecstasy and certain other drugs including GHB and Viagra because ritonavir can increase the levels of drug in the body dangerously. MDMA levels in patients taking ritonavir reach three to ten times those seen in other people.

In October 1996 Londoner Philip Kay died after taking 2.5 ecstasy tablets: the inquest found that he had levels of the drug in his body equivalent to taking 22 tablets. He had started taking full-dose ritonavir a few weeks earlier.