How does Alli work?

Orlistat (the active ingredient in Alli) promotes weight loss by decreasing the amount of dietary fat absorbed in your intestines.

Lipase, an enzyme found in the digestive tract, helps break down dietary fat into smaller components, so it can be used or stored for energy. Orlistat inhibits the work of lipase. When you take the drug with a meal, about 25 percent of the fat you consume isn't broken down and is eliminated through bowel movements.