"the way to reduce obesity"

Only two anti-obesity medications are currently approved by the FDA for long term use. One is orlistat (Xenical), which reduces intestinal fat absorption by inhibiting pancreatic lipase; the other is sibutramine (Meridia), which acts in the brain to inhibit deactivation of the neurotransmitters norepinephrine, serotonin, and dopamine (very similar to some anti-depressants), therefore decreasing appetite.

Rimonabant (Acomplia), a third drug, works via a specific blockade of the endocannabinoid system. It has been developed from the knowledge that cannabis smokers often experience extreme hunger pangs, which is often referred to as "the munchies". It has been approved in Europe for the treatment of obesity but has not yet received approval in the United States or Canada due to safety concerns.

Weight loss with these drugs is modest; over the longer term, average weight loss on orlistat is 2.9 kg, sibutramine is 4.2 kg and rimonabant is 4.7 kg. Orlistat and rimonabant lead to a reduced incidence of diabetes, and all three drugs have some effect on cholesterol. There is however little data on how these drugs affect the longer-term complications or outcomes of obesity.

There are a number of less commonly used medication. Some are approved for only short term use, others are used off label, and still others are used illegally. Most are appetite suppressants that act on either one or more neurotransmitters.Phendimetrazine (Bontril), diethylpropion, and phentermine are approved by the FDA for short term use while bupropion, topiramate, and zonisamide are sometimes used off label.

Certain drugs are useful depending on the comorbities present. Metformin is preferred in overweight diabetics as it may lead to mild weight loss in comparison to sulfonylureas or insulin.The thiazolidinediones, on the other hand, may cause weight gain, but decrease central obesity. Diabetics also achieve modest weight loss with fluoxetine (Prozac), orlistat and sibutramine over 12–57 weeks. The long-term health benefits of theses treatments however remains unclear.

Fenfluramine and dexfenfluramine were withdrawn from the market in 1997, while ephedrine (Ma Huang) was removed from the market in 2004

Dexamphetamines are not approve by the FDA for the treatment of obesity due to concerns regarding addiction These drug are all not recommended due to potential side effects. People however do occasionally get these drug illegally.