No 'Silver Bullet' For Weight Loss

Since the supplement ephedra was banned late last year, many people trying to lose weight have been looking for other options.

The Early Show's Dr. Mallika Marshall has a look at the prescription pills currently on the market, and a warning about which products to avoid.

Weight loss pills are not for everyone. In fact, they are for a minority of patients. They are typically prescribed to people who try but fail to lose weight through traditional methods such as diet and exercise, or for people who are so heavy that they need extra help.

And remember, there are also other options now available to people who are very overweight. They can have procedures such as gastric bypass surgery. Many people like the ease of just taking a pill, but even prescription pills that have been approved by the FDA can have side effects.

Here are some of the most popular prescription brands on the market that are sold specifically as weight-loss aids:

• Sibutramine is sold as Meridia. It works by making a person feel full, which will hopefully prevent him or her from eating as much. Unlike other weight-loss pills, sibutramine can be used for up to two years which can be very helpful because anyone who's tried to lose weight knows that it can take awhile. However, the drug can have side effects, including raising your blood pressure and heart rate. So if you have a pre-existing condition, such as heart disease or hypertension, then your doctor will probably prescribe something else. Some people on sibutramine also complain of dry mouth, headaches and constipation.
• Phentermine is sold under several brand names, including Adipex-P and Fastin. It was approved by the FDA in 1973, so there have been more studies on it than any of the other pills on the market. Phentermine works in much the same way that sibutramine does. But, unlike sibutramine, it can only be taken for eight weeks. This is not a very long time, which is why some doctors choose to prescribe other drugs. And it, too, carries side effects like increasing your heart rate.
• Orlistat is sold under the brand name of Xenical. It eliminates fats from the body before they are digested, so this may be a good option for people who tend to eat high-fat foods. Like sibutramine, it can be taken for about two years. However, taking this drug can be very unpleasant. It can cause bad stomach aches and diarrhea. Another side effect is that the drug prevents the body from absorbing certain vitamins which the body needs.

• Glucophage is sold as Metformin and is used to treat Type 2 diabetes. However, doctors have found that patients taking the drug often lose weight. But the drug is by no means a "silver bullet." People who don't have Type 2 diabetes often don't experience the same amount of weight loss as people who have the disease. Like Orlistat, it can cause digestive problems such as diarrhea.
• Bupropion is sold under the brand name of Wellbutrin and is an antidepressant. Like some drugs sold specifically to help lose weight, Bupropion makes users feel less hungry. A recent study found that 14 percent of those people who took the drug every day lost about 5 pounds in eight weeks. However, some people experience side effects including anxiety, constipation and nausea.

Marshall says that the great majority of these drugs have little or no science behind them and contain herbs and supplements which can actually do more harm than good.