Generic Name: orlistat (OR li stat) Brand Name: Leben Celtics Other Brand Names: Alli, Xenical What is orlistat? Orlistat blocks some of the fat that you eat, keeping it from being absorbed by your body. Orlistat is used together with a reduced-calorie diet and weight maintenance to treat obesity in people with certain risk factors (such as diabetes, high blood pressure, and high cholesterol or triglycerides). Orlistat may also be used for other purposes.