Orlistat is a medication that reduces the absorption of dietary fats in the gastrointestinal tract. It works by inhibiting pancreatic lipase, an enzyme that breaks down triglycerides into absorbable fatty acids. As a result, a portion of the ingested fat passes through the body unchanged and is eliminated in the stool. The drug is used as an adjunct to a reduced-calorie diet for the management of obesity in adults. By limiting caloric intake from fats, Orlistat can contribute to modest weight loss when combined with lifestyle changes. Its therapeutic effect is therefore primarily to decrease the amount of dietary fat that the body can store.

Orlistat is a lipase inhibitor used as an adjunct to diet and exercise for the management of obesity. It belongs to the class of medications that reduce the absorption of dietary fats by blocking gastric lipases. By inhibiting these enzymes Orlistat prevents the hydrolysis of triglycerides into free fatty acids and monoglycerides in the intestinal lumen. The undigested fat is then excreted in the feces leading to a net reduction in caloric intake. This mechanism also contributes to modest improvements in lipid profiles and glycemic control in some patients. Overall Orlistat provides a non-systemic approach to obesity treatment through targeted inhibition of fat digestion.

The most common side effects are typically mild and short lived. Many people experience nausea or a feeling of stomach discomfort. Headache and fatigue are also frequently reported. Dizziness or light headedness may occur especially when standing quickly. Some individuals notice mild skin reactions such as redness or itching. Changes in taste or dry mouth are usually temporary. Sleep disturbances like difficulty falling asleep can happen in a small number of cases. Overall these effects often diminish with continued use.

The most common side effects include headache. Fatigue or a general feeling of tiredness is also frequently reported. Nausea, often mild, can occur after taking certain medications. Dizziness or lightheadedness may be experienced by some individuals. Dry mouth is another typical mild effect observed. Some people notice a metallic taste in their mouth during treatment. Mild skin flushing or itching may appear as a transient reaction. Occasionally, mild abdominal discomfort is reported but usually resolves without intervention.