Orlistat is a pharmaceutical drug, sold over-the-counter under the name Alli, and under prescription as Xenical.
How it works: This weight loss pill works by inhibiting the breakdown of fat in the gut, making you take in fewer calories from fat.
Effectiveness: According to a big review of 11 studies, orlistat can increase weight loss by 6 pounds (2.7 kg) compared to a dummy pill (
Side effects: This drug has many digestive side effects, including loose, oily stools, flatulence, frequent bowel movements that are hard to control, and others. It may also contribute to deficiency in fat-soluble vitamins, such as vitamins A, D, E and K.
It is usually recommended to follow a low-fat diet while taking orlistat, in order to minimize side effects.
Orlistat, also known as Alli or Xenical, can reduce the amount of fat you absorb from the diet and help you lose weight. It has many side effects, some of which are highly unpleasant.