The pill, called Qsymia, is designed for those who are overweight and have at least one weight-related condition, such as high blood pressure or diabetes. It is expected to help them lose 10 percent of their weight, in combination with diet and exercise.
The drug was previously known as Qnexa. The FDA rejected it two years ago because of fears over increased heart rate and birth defects.
It was approved after the manufacturer began a risk management program, controlling its use.
Qsymia is a combination of two FDA-approved drugs, phentermine and topiramate, which have been known to help with weight loss. Phentermine is indicated for short-term weight loss in overweight or obese adults who are exercising and eating a reduced-calorie diet. Topiramate is an anticonvulsant that makes people feel more satisfied after eating.
The drug's maker, Vivus Inc., said it plans to bring the drug to market in the fourth quarter of this year. It hasn't yet decided what the pills will cost.
The Associated Press contributed to this report.