Manager, Nutrition Services
Joslin Diabetes Center
There are three medications approved by the U.S. Food and Drug Administration (FDA) for long-term weight loss. They are: orlistat (Xenical and Alli), lorcaserin (Belviq) and phentermine-topiramate (Qsymia). They are not considered high risk for developing a dependence, but you should be cautious if you have a history of drug or alcohol addiction.
If you are overweight or obese, these prescription medications can help you get to a healthier weight. They should be used along with lifestyle changes, such as eating a healthful, high-fiber, lower-calorie diet, being physically active and behavior modification.
Weight loss drugs, like most medications, do have potential side effects. No weight-loss medications should be used during pregnancy of if you're trying to become pregnant, and some of the medications may also be restricted for people with other conditions.
The three FDA-approved weight-loss drugs are:
- Orlistat. This drug prevents your body from absorbing about one-third of the fat you eat. Xenical is the prescription version of orlistat, approved for adults and children 12 and older. Alli is the lower-dose over-the-counter orlistat. It is not approved for children.
- Lorcaserin. This drug affects the chemicals in your brain that help decrease your appetite and make you feel full, so you eat less. It does not work for all people, so if you do not lose 5 percent of your weight within 12 weeks of starting the drug, the medication may not work for you, and you should talk with your health care professional about other options.
- Phentermine-topiramate. By combining two FDA-approved drugs, phentermine and topiramate, researchers created a new obesity drug for adults. The phentermine suppresses appetite, but used alone, it is only approved for two weeks. By combining a lower dosage of phentermine with extended-release topiramate, the drug has been shown to be safe for up to two years. Similar to lorcaserin, it is not effective for everyone.
There also are several FDA-approved over-the-counter appetite suppressants that affect the brain chemicals that regulate your appetite, but these medications do have the potential for abuse and are only FDA-approved for short-term use of up to 12 weeks. They include:
- phentermine (Adipex-P, Oby-Cap, Suprenza, T-Diet, Zantryl)
- benzphetamine (Didrex)
- diethylpropion (Tenuate, Tenuate Dospan)
- phendimetrazine (Adipost, Bontril PDM, Bontril Slow Release, Melfiat)
Some appetite suppressants may have serious side effects. You should not take them if you have heart disease, high blood pressure, overactive thyroid gland or glaucoma. Appetite suppressants, along with other over-the-counter remedies like diuretics and supplements, have not been found to be effective long term.
Weight loss is a serious, long-term endeavor, so be sure to discuss the options with your health care provider or consult a registered dietitian.
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