This is a review paper written for a medical audience that views ecstasy in terms of its risks. The author addresses the history of MDMA and ecstasy, the acute effects (desired effects, side effects and undesired effects), chronic effects (including a review of neurotoxicity studies), medical emergencies and addiction potential. The strongest sections of the paper are those on medical emergencies and addiction, and the weakest sections are on the history of the drug and the examination of potential neurotoxicity. Overall, the paper is notable for continually comparing the effects of "ecstasy" to those of amphetamines in general rather than considering ecstasy effects in isolation.