Is is true that orlistat is a stimulant?

No: It's the ingredient in Alli or xenical. It helps you lose weight by binding 30% of the fat you eat and eliminating it out your stool.

No: No, orlistat is not a stimulant except to make you run to the bathroom. It is the generic of xenical, and inhibits enzymes which allow you to digest fat. Much of the fat you eat comes out in your stools, which can become quite greasy. However, carbohydrates and proteins are supposedly digested normally.