Prescription Diet Pills

There are three types of prescription diet pills available: those that affect the brain, those that affect the central nervous system, and those that affect the digestive system. The most common weight loss pills are those that affect the brain, more specifically, appetite suppressants. The active ingredient in appetite suppressants most is phentermine hydrochloride or phendimetrazine, which are sympathomimetic amines. These chemicals affect appetite control centers in the brain, causing you to eat less. Phentermine-based diet pills include the generic form of the drug, as well as Meridia, Bontril, Ionamin, and Adipex. Another appetite suppressant is Didrex, which uses the active ingredient benzphetamine hydrochloride (similar to amphetamines and has high potential for psychological dependency) as an anorectic agent.

Tenuate is also an appetite suppressant, but uses a different active ingredient, diethylpropion. Diethylpropion is a sympathomimetic amine that stimulates the central nervous system, increasing your heart rate and blood pressure while decreasing your appetite, which promotes weight loss.

The third type of prescription diet pills affects your digestive system. The most popular drug, Xenical, uses the active ingredient Orlistat to block a certain amount of the fat you eat from being digested. Xenical is intended for individuals who are considerably overweight or obese.