In the SCOUT (Sibutramine Cardiovascular OUTcomes) study, sibutramine increased serious cardiovascular events, such as stroke or myocardial infarction, compared with placebo, and was consequently withdrawn from the market. The lesson learnt from this is the importance of patient selection, limiting the duration of treatment and stopping treatment in non-responders. Currently, phentermine and amfepramone (diethylpropion) are approved for short-term treatment of obesity (up to 3 months) and orlistat is approved for longer-term treatment; however, the gastrointestinal adverse effects of orlistat may be intolerable for some patients.