Medically reviewed by Drugs.com. Last updated on Feb 24, 2022.
Commonly used brand name(s)
In the U.S.
Available Dosage Forms:
Therapeutic Class: Dietary Fat Absorption Inhibitor
Pharmacologic Class: Lipase Inhibitor
Uses for Alli
Orlistat is used together with a reduced-calorie diet to help you lose weight and to help keep the lost weight from returning. It is also used in overweight people who may also have diabetes, high blood pressure, high cholesterol, or heart disease.
Orlistat works by keeping your intestines from absorbing some of the fats from the food that you eat. The undigested fat goes out of your body in your bowel movements.
This medicine is available both over-the-counter (OTC) and with your doctor's prescription.
Before using Alli
In deciding to use a medicine, the risks of taking the medicine must be weighed against the good it will do. This is a decision you and your doctor will make. For this medicine, the following should be considered:
Tell your doctor if you have ever had any unusual or allergic reaction to this medicine or any other medicines. Also tell your health care professional if you have any other types of allergies, such as to foods, dyes, preservatives, or animals. For non-prescription products, read the label or package ingredients carefully.
Appropriate studies performed to date have not demonstrated pediatric-specific problems that would limit the usefulness of orlistat in teenagers. Safety and efficacy have not been established in children younger than 12 years of age.
Appropriate studies performed to date have not demonstrated geriatric-specific problems that would limit the usefulness of orlistat in the elderly.
There are no adequate studies in women for determining infant risk when using this medication during breastfeeding. Weigh the potential benefits against the potential risks before taking this medication while breastfeeding.
Interactions with medicines
Although certain medicines should not be used together at all, in other cases two different medicines may be used together even if an interaction might occur. In these cases, your doctor may want to change the dose, or other precautions may be necessary. When you are taking this medicine, it is especially important that your healthcare professional know if you are taking any of the medicines listed below. The following interactions have been selected on the basis of their potential significance and are not necessarily all-inclusive.
Using this medicine with any of the following medicines is usually not recommended, but may be required in some cases. If both medicines are prescribed together, your doctor may change the dose or how often you use one or both of the medicines.
- Dabigatran Etexilate
- Eslicarbazepine Acetate
- Gabapentin Enacarbil
- Protein C
- Valproic Acid
Using this medicine with any of the following medicines may cause an increased risk of certain side effects, but using both drugs may be the best treatment for you. If both medicines are prescribed together, your doctor may change the dose or how often you use one or both of the medicines.
- Linoleic Acid
Interactions with food/tobacco/alcohol
Certain medicines should not be used at or around the time of eating food or eating certain types of food since interactions may occur. Using alcohol or tobacco with certain medicines may also cause interactions to occur. Discuss with your healthcare professional the use of your medicine with food, alcohol, or tobacco.
Other medical problems
The presence of other medical problems may affect the use of this medicine. Make sure you tell your doctor if you have any other medical problems, especially:
- Diabetes or
- Underactive thyroid—Use with caution. May increase risk for more serious side effects.
- Eating disorders (e.g., anorexia nervosa or bulimia) or
- Hyperoxaluria (high oxalic acid in the urine), history of or
- Kidney failure or
- Kidney stones or
- Liver disease—Use with caution. May make these conditions worse.
- Gallbladder problems or
- Malabsorption syndrome (problems with absorbing or digesting food)—Should not be used in patients with these conditions.
Proper use of Alli
This section provides information on the proper use of a number of products that contain orlistat. It may not be specific to Alli. Please read with care.
Take this medicine only as directed by your doctor. Do not take more of it, do not take it more often, and do not take it for a longer time than your doctor ordered.
This medicine comes with a patient information insert. Read and follow the instructions in the insert carefully. Talk to your doctor if you have any questions.
Orlistat prevents the absorption of some of the fat you eat. You should take it with liquids during the meal or up to 1 hour after eating. If you occasionally miss a meal or eat a meal that contains no fat, you should skip the dose of orlistat.
Because orlistat may decrease the amount of some vitamins that your body absorbs from food, you will need to take a multivitamin supplement once a day. Take the vitamin supplement at least 2 hours before or after taking orlistat. You may also take your multivitamin supplement at bedtime.
When using orlistat, your diet should contain no more than 30% of calories as fat. More fat in your diet will increase the side effects of this medicine. Your diet should be nutritionally balanced, and your daily intake of fat, carbohydrates, and protein should be distributed over three main meals.
Carefully follow your doctor's instructions for a reduced-calorie diet plan and regular exercise. Talk with your doctor before starting any exercise program.
If you are using cyclosporine (Gengraf®, Neoral®, Sandimmune®) and levothyroxine (Levothroid®, Synthroid®), do not take them at the same time that you take this medicine. It is best to take cyclosporine at least 3 hours before or 3 hours after taking orlistat. Levothyroxine must be used at least 4 hours before or 4 hours after you take orlistat.
The dose of this medicine will be different for different patients. Follow your doctor's orders or the directions on the label. The following information includes only the average doses of this medicine. If your dose is different, do not change it unless your doctor tells you to do so.
The amount of medicine that you take depends on the strength of the medicine. Also, the number of doses you take each day, the time allowed between doses, and the length of time you take the medicine depend on the medical problem for which you are using the medicine.
- For oral dosage form (capsules):
- For treatment of obesity:
- Adults and teenagers—120 milligrams (mg) three times a day with meals containing fat.
- Children younger than 12 years of age—Use and dose must be determined by your doctor.
- For treatment of obesity:
If you miss a dose of this medicine, skip the missed dose and go back to your regular dosing schedule. Do not double doses.
Store the medicine in a closed container at room temperature, away from heat, moisture, and direct light. Keep from freezing.
Keep out of the reach of children.
Do not keep outdated medicine or medicine no longer needed.
Ask your healthcare professional how you should dispose of any medicine you do not use.
Precautions while using Alli
It is very important that your doctor check your or your child's progress at regular visits, to make sure that this medicine is working properly. Blood and urine tests may be needed to check for unwanted effects.
Using this medicine while you are pregnant can harm your unborn baby. Use an effective form of birth control to keep from getting pregnant. If you think you have become pregnant while using this medicine, tell your doctor right away.
For patients with diabetes: Weight loss may result in an improvement in your condition, and your doctor may need to change your dose of oral diabetes medicine or insulin.
This medicine may cause a serious type of allergic reaction called anaphylaxis. Anaphylaxis can be life-threatening and requires immediate medical attention. Call your doctor right away if you or your child have a rash; itching; hoarseness; trouble breathing; trouble swallowing; or any swelling of your hands, face, or mouth while you are using this medicine.
Stop using this medicine and check with your doctor right away if you or your child have pain or tenderness in the upper stomach; pale stools; dark urine; loss of appetite; nausea; unusual itching; unusual tiredness or weakness; or yellow eyes or skin. These could be symptoms of a serious liver problem.
This medicine may increase your risk of having kidney stones. Check with your doctor right away if you or your child have blood in the urine, nausea and vomiting, pain in the groin or genitals, or sharp back pain just below the ribs.
Weight loss with this medicine may increase your risk of having gallstones. Check with your doctor right away if you or your child have severe stomach pain with nausea and vomiting.
Do not take other medicines unless they have been discussed with your doctor. This includes prescription or nonprescription (over-the-counter [OTC]) medicines and herbal or vitamin supplements.
Alli side effects
Along with its needed effects, a medicine may cause some unwanted effects. Although not all of these side effects may occur, if they do occur they may need medical attention.
Check with your doctor immediately if any of the following side effects occur:
- Bladder pain
- body aches
- difficulty with breathing
- ear congestion
- general feeling of discomfort or illness
- loss of appetite
- loss of voice
- lower back or side pain
- muscle aches and pains
- nasal congestion
- runny nose
- sore throat
- trouble sleeping
- unusual tiredness or weakness
- Tightness in the chest
- tooth or gum problems
- troubled breathing
- Bloody or cloudy urine
- change in hearing
- contagious diarrhea
- dark urine
- difficult or painful urination
- fast heartbeat
- frequent urge to urinate
- general tiredness and weakness
- joint pain, stiffness, or swelling
- large, hive-like swelling on the face, eyelids, lips, tongue, throat, hands, legs, feet, or sex organs
- light-colored stools
- noisy breathing
- pain in the ears
- redness of the skin
- shortness of breath
- skin blisters
- swelling of the eyelids, face, lips, hands, or feet
- troubled swallowing
- upper right abdominal or stomach pain
- yellow eyes and skin
Incidence not known
- blurred vision
- cold sweats
- cool, pale skin
- dry skin and hair
- feeling cold
- hair loss
- hoarseness or husky voice
- increased hunger
- loss of appetite
- muscle cramps and stiffness
- pains in the stomach, side, or abdomen, possibly radiating to the back
- weight gain
Some side effects may occur that usually do not need medical attention. These side effects may go away during treatment as your body adjusts to the medicine. Also, your health care professional may be able to tell you about ways to prevent or reduce some of these side effects. Check with your health care professional if any of the following side effects continue or are bothersome or if you have any questions about them:
- Abdominal or stomach pain or discomfort
- back pain
- difficulty with moving
- gas with leaky bowel movements
- inability to hold bowel movement
- increases in bowel movements
- loss of bowel control
- oily bowel movements
- oily spotting of underclothes
- Itching of the vagina or genital area
- menstrual changes
- pain during sexual intercourse
- rectal pain or discomfort
- thick, white vaginal discharge with no odor or with a mild odor
Other side effects not listed may also occur in some patients. If you notice any other effects, check with your healthcare professional.
Call your doctor for medical advice about side effects. You may report side effects to the FDA at 1-800-FDA-1088.
More about Alli (orlistat)
- Side effects
- Drug interactions
- Dosage information
- During pregnancy or Breastfeeding
- Reviews (107)
- Drug images
- Pricing & coupons
- En español
- Drug class: peripherally acting antiobesity agents
- FDA approval history
- Other brands
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