Orlistat works by preventing the absorption of dietary fats. Specifically, it inhibits pancreatic lipases, enzymes your body uses to break down fats in your food. Without these enzymes working properly, a significant portion of ingested fat passes through your digestive system undigested and is eliminated in your stool.
How Much Fat is Blocked?
Studies show that orlistat can block the absorption of about 25-30% of dietary fat. This isn’t a complete blockage, but it can contribute to weight loss when combined with a reduced-calorie diet and increased physical activity.
Consequences of Unbroken Fats
The undigested fat leads to increased bowel movements and potentially oily stools. This is a common side effect, so understanding this mechanism helps manage expectations and side effects.
Dietary Fat and Orlistat’s Efficacy
| High-fat meal | Increased likelihood of gastrointestinal side effects |
| Balanced diet with moderate fat | More manageable side effects, better weight loss results |
Fat-Soluble Vitamins and Orlistat
Since orlistat reduces fat absorption, it can slightly decrease the absorption of fat-soluble vitamins (A, D, E, and K). Consider a multivitamin that includes these vitamins to mitigate any potential deficiency.
Drug Interactions
Orlistat can interact with certain medications, including cyclosporine and some blood thinners. Always consult your doctor or pharmacist about potential drug interactions before starting orlistat.
