How long does it take to lose weight on alli orlistat is a lipase inhibitor which used for helping you to lose your weight and also keep it from returning. Orlistat is prescribed for obese individuals and for overweight people who have other health problems such as diabetes, high blood pressure or high cholesterol levels. Orlistat blocks the absorption of dietary fat into the bloodstream, thereby reducing the number of calories you get from a meal. You may use Orlistat together with diet and exercises to get more benefits. Also, note that as long as you take the drug you will get a result. Many people using this medicine do not have serious side effects. Viagra is contraindicated in patients taking another medicine to treat impotence or using a nitrate drug for chest pain or heart problems. This medicine should not be taken by women and children as well as in patients with a known hypersensitivity to any component of the tablet.