The first new weight-loss drugs in more than a decade are now on pharmacists' shelves. Will these medications provide the solution many overweight women are seeking? The September 2012 issue of Harvard Women's Health Watch looks at the benefits—and risks—of both new and established weight-loss drugs.

In June, the FDA approved lorcaserin (Belviq). It suppresses hunger by stimulating a receptor serotonin, a chemical messenger in the brain that regulates fullness and metabolism. A month later, the FDA approved Qsymia, a combination of phentermine and the antiseizure/antimigraine drug topiramate. Qsymia also suppresses appetite, and it appears to be more effective for weight loss than any other single drug.

These highly anticipated new medications join several existing weight-loss drugs. Orlistat (Xenical) works by blocking fat absorption, while phentermine (Adipex-P, Pro-Fast), diethylpropion (Tenuate), and phendimetrazine (Bontril, Adipost, Anorex-SR) suppress appetite.

These drugs can promote weight loss, but they can't "cure" obesity. "The biggest message that I try to relate to patients is that there is no magic bullet," says Dr. W. Scott Butsch, an obesity specialist who is an instructor in medicine at Harvard Medical School. In studies of weight-loss medications, women lost about 5% to 10% of their initial body weight over a year. But they also had to watch their diet and exercise.

How do you know if you're a good candidate for weight-loss drugs? You might be if

• you have a BMI higher than 30 (the definition of obesity), or have a BMI higher than 27 along with health problems related to your weight—such as type 2 diabetes (you can calculate your BMI at www.health.harvard.edu/bmi).
• you are overweight and actively dieting and exercising, but are unable to lose weight.

You'll need to consider with your doctor whether the risks of using a weight-loss drug, which range from heart problems and liver damage to possible addiction, are worth the weight you'll lose on it. For some overweight and obese women, they may be. Losing just 5% to 10% of body weight can help reduce disease risk factors such as high blood pressure, blood sugar, and cholesterol.

Read the full-length article: "Weight-loss drug review"