This medication is used with a doctor-approved exercise, behavior change, and reduced-calorie diet program to help you lose weight. It is used by certain overweight people, such as those who are obese or have weight-related medical problems. Taking orlistat can also help keep you from gaining back weight you have lost. Losing weight and keeping it off can lessen the many health risks that come with obesity, including heart disease, diabetes, high blood pressure, and a shorter life.

Dietary fats need to be broken down into smaller pieces before the body can absorb them. Orlistat works by blocking the enzyme that breaks down fats in your diet. This undigested fat then passes out of your body in your bowel movement. Orlistat does not block the absorption of calories from sugar and other non-fat foods, so you still need to restrict your total intake of calories.

If you are taking the over-the-counter product to self-treat, read all directions on the product package before taking this medication.

If your doctor has prescribed this medication, read the Patient Information Leaflet if available from your pharmacist before you start taking orlistat and each time you get a refill. Take this medication by mouth as directed by your doctor, usually 3 times daily. Take it with liquid sometime during each meal that contains fat or within 1 hour after the meal. If you miss a meal or your meal contains no fat, skip that dose of the medication. To decrease the chance of unpleasant side effects, it is very important that no more than 30% of the calories in your diet come from fat. Your daily intake of fat, protein, and carbohydrates should be evenly spread over 3 main meals.

Do not increase your dose or use this drug more often or for longer than prescribed. Your condition will not improve any faster, and your risk of side effects will increase.

Because this drug can interfere with the absorption of certain vitamins (fat-soluble vitamins including A, D, E, K), a daily multivitamin supplement containing these nutrients is recommended. Take the multivitamin at least 2 hours before or 2 hours after taking orlistat (such as at bedtime).

If you take cyclosporine, take it at least 3 hours before or after orlistat to make sure the full dose of cyclosporine is absorbed into your bloodstream. If you take levothyroxine, take it at least 4 hours before or after orlistat.

You should see some weight loss within 2 weeks after you start orlistat. Tell your doctor if your condition does not get better or if it gets worse.

Changes in your bowel function often occur because of the unabsorbed fat. Fatty/oily stool, oily spotting, intestinal gas with discharge, a feeling of needing to have a bowel movement right away, increased number of bowel movements, or poor bowel control may occur. These side effects may get worse if you eat more fat than you should. If these effects last or get worse, notify your doctor promptly.

If your doctor has directed you to use this medication, remember that your doctor has judged that the benefit to you is greater than the risk of side effects. Many people using this medication do not have serious side effects.

Stop taking this medication and tell your doctor right away if you have any serious side effects, including:

• symptoms of liver disease (such as nausea/vomiting that doesn't stop, severe stomach/abdominal pain, dark urine, yellowing eyes/skin)
• symptoms of kidney stones (such as back pain, pain when urinating, pink/bloody urine)

A very serious allergic reaction to this drug is rare. However, get medical help right away if you notice any symptoms of a serious allergic reaction, including:

• rash
• itching/swelling (especially of the face/tongue/throat)
• severe dizziness
• trouble breathing

This is not a complete list of possible side effects. If you notice other effects not listed above, contact your doctor or pharmacist.

In the US - Call your doctor for medical advice about side effects. You may report side effects to FDA at 1-800-FDA-1088 or at www.fda.gov/medwatch.

In Canada - Call your doctor for medical advice about side effects. You may report side effects to Health Canada at 1-866-234-2345.

Before taking orlistat, tell your doctor or pharmacist if you are allergic to it; or if you have any other allergies. This product may contain inactive ingredients, which can cause allergic reactions or other problems. Talk to your pharmacist for more details.

Before using this medication, tell your doctor or pharmacist your medical history, especially of:

• a certain digestive problem (chronic malabsorption syndrome)
• a certain gall bladder problem (cholestasis)
• underactive thyroid (hypothyroidism)
• kidney problems (such as kidney stones, hyperoxaluria)
• certain eating disorders (anorexia nervosa/bulimia)
• HIV infection
• seizures

Before having surgery, tell your doctor or dentist about all the products you use (including prescription drugs, nonprescription drugs, and herbal products).

If you are diabetic, weight loss may improve your blood sugar control. Be sure to check your blood sugar regularly and tell your doctor the results. Your doctor may need to adjust your diabetes medication, exercise program, or diet.

This medication must not be used during pregnancy. Weight loss offers no potential benefit to a pregnant woman and may harm an unborn baby. If you become pregnant or think you may be pregnant, tell your doctor right away.

It is unknown if this drug passes into breast milk. Consult your doctor before breastfeeding.

See also How to Use section.

Drug interactions may change how your medications work or increase your risk for serious side effects. This document does not contain all possible drug interactions. Keep a list of all the products you use (including prescription/nonprescription drugs and herbal products) and share it with your doctor and pharmacist. Do not start, stop, or change the dosage of any medicines without your doctor's approval.

Some products that may interact with this drug include:

• "blood thinners" (such as warfarin)
• HIV medications (such as atazanavir, efavirenz, emtricitabine, lopinavir, tenofovir)
• ritonavir
• triheptanoin

If you are taking medications to treat seizures, orlistat may cause these drugs to not work as well. Stop taking orlistat and tell your doctor right away if your seizures are happening more often or are getting worse.

If someone has overdosed and has serious symptoms such as passing out or trouble breathing, call 911. Otherwise, call a poison control center right away. US residents can call 1-800-222-1222. Canada residents can call 1-844-764-7669.

If this medication has been prescribed for you, do not share this medication with others.

Lab tests (such as kidney function) may be done while you are taking this medication. Keep all medical and lab appointments. Consult your doctor for more details.

For best results, this medication should be used along with a doctor-approved exercise program and diet plan. Consult your doctor or dietician for help designing an appropriate exercise and food plan for you.

If you miss a dose, take it as soon as you remember. If it is more than 1 to 2 hours since your meal, skip the missed dose since most of the fat from your meal will already have been absorbed and the medication will not work. Do not double the dose to catch up.

Store at room temperature away from light and moisture. Do not store in the bathroom. Keep all medications away from children and pets.

Do not flush medications down the toilet or pour them into a drain unless instructed to do so. Properly discard this product when it is expired or no longer needed. Consult your pharmacist or local waste disposal company.