Orlistat CAS #: 96829-58-2 Molecular formula: C29H53NO5 Molecular weight: 495.73 Formulation: White powder to off-white powder Purity: ¡Ý99% by HPLC Description:Orlistat is used with a low-calorie diet to help you lose weight and to maintain your weight after weight loss.Mechanism Orlistat is in a class of drugs called lipase inhibitors. It works in your intestines, where it blocks some of the fat you eat from being absorbed and digested. This undigested fat is then removed in your bowel movements .