Very few side effects are reported from Acomplia as compared to some of the other weight loss medications.

In comparison, Dexatrim had many complaints to Poison Control Centers - 47,000 in 1989 alone.  The drug Dexatrim became available as an over the counter drug in the late 1970s, which is also known by the names Accutrim, Diadex, Dex-a-Diet, Prolamine, Propagest, and Unitrol.  Dexatrim, which is Phenylpropanolamine, has some harsh side effects Amongst some of the side effects that have been reported are; anxiety, vomiting, disorientation, insomnia, nausea, palpitations, headache, hallucinations, a rebound effect of fatigue and hyperphagia, dangerously high blood pressure,  heart and kidney damage, abnormal heart rhythm, heart attack, strokes, psychosis, and death.

Another weight loss medication Xenical also had reported side effects and had caused an allergic reaction in some patients. Xenical also known as Orlistat can have a number of side effects. Amongst the more common side effects of Xenical can be oily or fatty stools, oily spotting,  orange or brown colored oil in your stool,  gas with discharge, an oily discharge, an inability to control bowel movements, an urgent need to go to the toilet, or an increased number of bowel movements. Avoiding fatty food reduces these side effects.  These side effects result from the drug blocking the fat from your diet.  Many find that if they continue taking Xenical, the side effects often go away.  

Some side effects are reported with Acomplia and the ones that cause the most concern are related to depression and psychosis. The results of the 1st year of clinical trials showed that patients taking the 20mg dosage of Rimonabant reported 50 percent more adverse events leading to discontinuation, than those in the placebo group.