Phentermine, and the chemically related medications phendimetrazine and diethylproprion, are prescription appetite suppressants used for the treatment of excess weight and obesity. When used in conjunction with a lower calorie diet and increased physical activity, these drugs are extremely effective tools for helping individuals lose weight and maintain weight loss.

Phentermine, phendimetrazine and diethylproprion suppress appetite by changing the chemistry in the brain in a way that decreases the hunger drive. Individuals taking these medications lose weight because they are less hungry and thus consume fewer calories. These medications help you feel more in control of your appetite and food cravings. They can increase your satiety, which means that when you eat you will feel full sooner. Phentermine, phendimetrazine and diethylproprion can also help take your mind off food so that you can think about other things.

No. These medications do not alter metabolism or cause your body to burn more fat.

Yes. Phentermine, phendimetrazine and diethylproprion are safe medications with few side effects. Phentermeine was approved by the FDA in 1959 and has been taken by millions of patients. These medications have never been associated with a serious medical complication.

No. Fen/fen was a two drug combination of fenfluramine and phentermine. Fenfluramine is not related chemically to phentermine. Fenfluramine was taken off the market in 1997 because it was thought to cause a serious complication known as pulmonary hypertension in some patients. Phentermine has never been associated with pulmonary hypertension or any other medical complication.