Orlistat is in a class of drugs called lipase inhibitors. It works in the intestines, where it blocks some of the fat from being absorbed and disgested. This undigested fat is then removed in bowel movements

Orlistat comes as a capsule to take by mouth. It is usually taken three times a day with each main meal that contains fat. Take orlistat during or up to 1 hour after a meal. If a meal is missed or does not have fat, you may skip your dose.

The most common side effect of orlistat is changes in bowel movement habits. Tell your doctor if any of these symptoms are severe or do not go away:

oily, spotting BMs
gas with discharge
urgent need to have a BM
oily or fatty stools
an oily discharge
increased number of BMs
inability to control BMs
orange or brown color of a BM
stomach pain
irregular menstrual periods

If you experience any of the following symptoms, call your doctor immediately:

itching
redness of skin
skin rash or hives
swelling
chest pain
difficulty breathing
fever

Tell your doctor and pharmacist what prescription and nonprescription drugs you are taking, especially anticoagulants ('blood thinners') such as warfarin (Coumadin); medications for diabetes, such as glipizide (Glucotrol), glyburide (DiaBeta, Dynase, Micronase), metformin (Glucophage), and insulin; other medications for weight loss; pravastatin (Pravachol); vitamins such as beta-carotene and vitamins A, E, and K; and herbal products. If you are taking cyclosporine (Neoral, Sandimmune), take it 2 hours before or 2 hours after orlistat.

Symptoms of an orlistat overdose are not known. If you suspect an overdose, please consult your physician, or call the poison centre.

Do not take more of this medication than has been prescribed for you. Doses greater than 120 mg three times a day have not been shown to provide any additional weight-loss benefit.

Take the missed dose up to one hour after a meal. If more than one hour has passed since your last meal, skip the dose you missed and take only your next regularly scheduled dose as directed. Do not take a double dose of this medication.

Orlistat is used for obesity management, including weight loss and weight maintenance.

Orlistat may also be used in combination with diabetes medications to improve blood glucose control for overweight or obese people with type 2 diabetes.

Keep this medication in an airtight container and out of reach of children. Store it at room temperature and away from excess heat and moisture (not in the bathroom). Throw away any medication that is outdated.

Before taking orlistat,
tell your doctor and pharmacist if you are allergic to orlistat or any other drugs.
tell your doctor if you have or have ever had anorexia nervosa or bulimia, gallstones, thyroid disease, diabetes, kidney problems, or if you consistently have problems absorbing food (malabsorption syndrome).
tell your doctor if you are pregnant, plan to become pregnant, or are breast-feeding.