GENERIC NAME: orlistat
BRAND NAME: Xenical, alli
DRUG CLASS AND MECHANISM: Orlistat is a drug that promotes loss of weight by preventing the digestion and absorption of fat in food. In the intestine, an enzyme called lipase (produced primarily by the pancreas) breaks apart fat in food so that it can be absorbed into the body. Orlistat blocks the action of lipase and thereby prevents the breakup and absorption of fat. Orlistat blocks absorption of about 25% of the fat in a meal. The unabsorbed fat is excreted in the stool. The FDA approved Orlistat by prescription in 1999. alli, a lower dose formulation of orlistat, was approved for purchase without a prescription "over the counter" in 2007.
PRESCRIBED FOR: Orlistat is combined with a reduced-calorie diet to promote weight loss. Orlistat also may be used to prevent weight gain after weight has been lost. Candidates for treatment with orlistat are patients who are obese with a body mass index (a measure of obesity) of more than 30 kg/m2. Candidates also include patients with a body mass index of between 27 and 30 kg/m2 if other risk factors for arteriosclerosis are present such as high blood pressure, diabetes, and elevated blood cholesterol or triglycerides. Based on several scientific studies, the average weight loss that is achieved when orlistat is taken as recommended for six months to one year is 12.4 to 13.4 pounds.
Report Problems to the Food and Drug Administration
You are encouraged to report negative side effects of prescription drugs to the FDA. Visit the FDA MedWatch website or call 1-800-FDA-1088.
Need help identifying pills and medications?
Use the pill identifier tool on RxList.