Orlistat is a medication used for weight loss. It works by preventing the absorption of some of the fat from the food you eat, helping to reduce overall calorie intake. Orlistat is available both over the counter (as Alli) and by prescription (as Xenical).

Orlistat works by inhibiting the enzyme lipase in your digestive system. Lipase breaks down fat from your diet so it can be absorbed by your body. By inhibiting this enzyme, Orlistat prevents approximately 25-30% of dietary fat from being absorbed, which is then excreted in your stool.

Orlistat is suitable for overweight and obese adults with a BMI of 30 or higher, or those with a BMI of 27 or higher who have weight-related conditions such as type 2 diabetes, high blood pressure, or high cholesterol.

Take one 60 mg (over-the-counter) or 120 mg (prescription) capsule three times a day with each main meal that contains fat. Swallow the capsule with water during or up to an hour after the meal. If you skip a meal or eat a meal without fat, you should skip that dose of Orlistat.

When combined with a reduced-calorie, low-fat diet and regular physical activity, Orlistat can help users lose 5-10% of their body weight. Clinical studies show that Orlistat users lose significantly more weight than those using diet alone.

Common side effects include gastrointestinal issues such as oily stools, flatulence, frequent bowel movements, and abdominal discomfort. These side effects are usually mild and tend to decrease over time as your body adjusts to the medication.