Alli blocks some of the fat that you eat, keeping it from being absorbed by your body. Alli is used together with a reduced-calorie diet and weight maintenance to treat obesity in people with certain risk factors (such as diabetes, high blood pressure, and high cholesterol or triglycerides). Alli may also be used for purposes other than those listed in this medication guide.

The health and medical information provided here is for general purposes only and is not a substitute for the expertise and judgment of your physician, or other health care professional. It should not be understood to indicate that the use of this medicine is safe, appropriate or effective for you. Always consult your health care professional before using this, or any other, drug.

Do not take Alli if you are allergic to orlistat, or if you have gallbladder problems, or chronic malabsorption syndrome (an inability to absorb food and nutrients properly).
Before taking Alli, tell your doctor if you have an underactive thyroid, a history of gallstones or pancreatitis, type 1 or type 2 diabetes, an eating disorder, liver disease, or if you take other weight-loss medications (prescription or over-the-counter).
Do not give over-the-counter orlistat (Alli) to a child younger than 18 years old. Prescription orlistat (Alli) should not be used by anyone age 12 to 18 without the advice of a doctor. Alli should be used only by the person it was prescribed or recommended for and should never be shared with another person, especially someone who has a history of eating disorder. Store this medication in a place where others cannot get to it.
Alli is only part of a complete program of treatment that also includes diet, exercise, and weight control. Your daily intake of fat, protein, and carbohydrates should be evenly divided over all of your daily meals. Follow your diet, medication, and exercise routines very closely.
While taking Alli avoid a diet that is high in fat. High-fat meals taken in combination with Alli can increase your risk of unpleasant side effects on your stomach or intestines.

Get emergency medical help if you have any of these signs of an allergic reaction: hives; difficulty breathing; swelling of your face, lips, tongue, or throat. Stop taking Alli and call your doctor at once if you have severe pain in your upper stomach spreading to your back, nausea and vomiting, and a fast heart rate. These could be signs of pancreatitis.
The following side effects occur commonly with the use of Alli. They are the natural effects of Alli`s fat-blocking action and are actually signs that the medication is working properly. These side effects are usually temporary and may lessen as you continue treatment with Alli:
oily spotting in your undergarments;
oily or fatty stools;
orange or brown colored oil in your stool;
gas with discharge, an oily discharge;
loose stools, or an urgent need to go to the bathroom, inability to control bowel movements;
an increased number of bowel movements;
stomach pain, nausea, vomiting, diarrhea, rectal pain; or
weakness, dark urine, clay-colored stools, itching, loss of appetite, or jaundice (yellowing of the skin or eyes).
Other side effects that may occur while taking Alli include:
problems with your teeth or gums;
cold symptoms such as stuffy nose, sneezing, cough;
fever, chills, sore throat, flu symptoms;
headache, back pain; or
mild skin rash.

Take Alli exactly as directed on the label, or as it was prescribed for you. Do not take the medication in larger amounts, or take it for longer than recommended by your doctor. Follow the directions on your prescription label.
Alli comes with patient instructions for safe and effective use. Follow these directions carefully. Ask your doctor or pharmacist if you have any questions.
Alli is only part of a complete program of treatment that also includes diet, exercise, and weight control. Your daily intake of fat, protein, and carbohydrates should be evenly divided over all of your daily meals. Follow your diet, medication, and exercise routines very closely.
Take Alli during or within 1 hour after a meal that contains some fat (no more than 30% of the calories for that meal). Alli is usually taken 3 times daily.
If you skip a meal or you eat a meal that does not contain any fat, skip your Alli dose for that meal.
The fat content of your daily diet should not be greater than 30% of your total daily caloric intake. For example, if you eat 1200 calories per day, no more than 360 of those calories should be in the form of fat.
Read the label of all food items you consume, paying special attention to the number of servings per container. Your doctor, nutrition counselor, or dietitian can help you develop a healthy eating plan.
Your doctor may recommend you take vitamin and mineral supplements while you are taking Alli. This medication can make it harder for your body to absorb fat-soluble vitamins, such as vitamins A, D, E, and K. Follow your doctor`s instructions about the type of multi-vitamin or mineral supplement to use.
Take the supplement at least 2 hours before or after you take Alli.
Store Alli at room temperature away from moisture and heat. Keep the bottle tightly closed.
Keep track of how many capsules have been used from each new bottle. Alli is a drug that may be misused as a weight-loss aid, and you should be aware if any person in the household is using this medicine improperly or without a prescription.