Overweight and obesity are serious conditions associated with a number of chronic health problems. More than two-thirds of the American adult population are considered overweight or obese.

The cornerstone of successful weight loss involves lifestyle changes, such as eating a healthful, high-fiber, lower-calorie diet, being physically active, and behavior modification. In addition, there are several prescription medications that can augment the benefits of these lifestyle changes. Like many medications, weight loss drugs do have side effects and these effects are sustained only for the time the medication is used.

The two medications approved by the U.S. Food and Drug Administration (FDA) for long-term weight loss are sibutramine (Meridia) and orlistat (Xenical). Meridia works by tricking the brain into making you feel full quickly. It can cause increased blood pressure, headache, dry mouth and constipation. Xenical prevents your body from absorbing fat. It can interfere with the absorption of fat-soluble vitamins, and cause diarrhea and abdominal pain. Neither medication is considered high risk for developing a dependence, although care should be taken in those with a history of drug or alcohol abuse.

There are several new drugs in clinical trials, many of which work by stimulating or suppressing the body's own hormones. Whether they turn out to be effective and safe long term is a question for the future. There are also numerous over-the-counter supplements and remedies that claim to induce weight loss. Most are appetite suppressants or diuretics of one sort or another. None have been found to be effective long term and some, like ephedra, which is now banned, have been linked to serious side effects.

Some issues to think about before considering a weight loss medication:

1. Your degree of overweight: weight loss medications are usually prescribed for people with a body mass index (BMI) over 27 who have additional complications, such as diabetes; or for those with BMIs over 30 without complications. BMI is a measure of weight status: people with BMIs from 25 to 29.9 are considered overweight; those with BMIs of 30 and above are considered obese.
2. Your degree of success with other weight loss programs or methods.
3. Your ability to comply with taking the medications and making long-term lifestyle changes.

Weight loss is a serious, long-term endeavor. You should always discuss the various options with your health care provider or consult a registered dietitian.