No existing weight loss drug has an acceptable harm-benefit balance. Liraglutide, a GLP-1 agonist administered by subcutaneous injection and already authorised in type 2 diabetes, is also approved for use in the European Union by obese patients or overweight individuals with other cardiovascular risk factors. The recommended dose in this setting is 3 mg per day, instead of the dose of 1.2 to 1.8 mg per day used in diabetes. In four randomised, double-blind, placebo-controlled trials, each lasting one year, mean weight loss with liraglutide, beyond the placebo effect, was about 5% among patients initially weighing between 100 and 118 kg. These trials were not designed to show an effect of liraglutide on complications of excess weight. Gallstones, one of the complications of obesity, were more frequent in the liraglutide groups. Partial weight regain was reported during the 3 months following liraglutide withdrawal. effects, including pancreatic disorders. Patients should not be exposed to these unjustified risks. The known adverse effect profile of liraglutide, which includes severe pancreatitis and gallstones, was confirmed in the trials in obese patients. Gastrointestinal disorders (nausea, vomiting and diarrhoea) were very frequent. Hypoglycaemic episodes, sometimes severe, have mainly been reported in diabetic patients. Reactions at the injection site can also be serious. In trials in obese patients, liraglutide was associated with an increased risk of miscarriage. In practice, sometimes excessive weight loss is a known adverse effect of GLP-1 agonists used in diabetes. Many patients lose several kilograms with high-dose liraglutide but regain the weight after treatment discontinuation. Liraglutide has no proven impact on complications of obesity and carries a risk of serious adverse.