Anti-obesity drugs are formulated to reduce or drugs to control weight. These pharmacological treatments prescribed by a doctor. They are typically reserved for cases of life-threatening obesity and not for those that are simple diets. This severity is due to the change of use of the vital processes in the body, if these medications taken. The processes can also be affected normal stimulation of appetite, increasing the body's metabolism and in the absorption of some nutrients.

The brain has what is known as cannabinoid receptors that are involved in the appetite of the normal stimulation. Some studies have shown that anti-obesity drugs that interfere with or block these receptors have been produced dangerous side effects. Depression that was severe enough to cause suicidal thoughts may in some patients, one of the reasons why the United States Food and Drug Administration rejected the approval of a drug called Acomplia ®. Other anti-obesity effect of a partial or complete block of the degradation of fats, thereby inhibiting proper absorption of fat. Although morbidly obese people usually have a need for food to reduce their intake of fatty acids, fats are still important nutrients for good health.

Generally, most doctors try to healthy weight loss with their patients about proper diet, regular physical activity to achieve and change of behavior. If such methods reduce to weigh at least 10 percent after three months after failing a weight loss program that could be prescribed for the treatment of obesity. Obese people who take these drugs are still encouraged to plan of course weight control with a healthy diet, regular exercise and changes in eating habits.

There are two types of anti-obesity: those affecting the gastrointestinal system and those that affect the central nervous system. Anti-obesity drugs-influence system, the stomach, such as orlistat, are pancreatic lipase inhibitors, because they interfere with the proper fat intake.