Generic Alli Orlistat works by inhibiting pancreatic lipase, an enzyme that breaks down triglycerides in the intestine. Without this enzyme, triglycerides from the diet are prevented from being hydrolyzed into absorbable free fatty acids and are excreted undigested.

Xenical Generic Orlistat will help you to lose weight by blocking the absorption of fats into your digestive system. The fats are eliminated from your body through bowel movements.