COMMON BRAND: Alli, Xenical

Orlistat is an oral prescription, and over-the-counter drug belongs to a class of drugs known as lipase inhibitors. This drug works by blocking lipase that breaks down fats present in your diet. This undigested fat then passes out of your body in your bowel movement.

What is Orlistat used for?

Orlistat is used along with low-calorie diet, low-fat diet and exercise program to help people lose weight. Prescription orlistat is used by overweight people having a certain complication like high blood pressure, high cholesterol, or heart disease, or diabetes. It is also used in post-weight-loss individuals to maintain their weight (gaining back).

How to use Orlistat?

If adults above 18 years of age are taking orlistat over-the-counter for self-treatment, read all instruction carefully on the product package before you initiate taking this medication. If orlistat prescribed to you, read all patient information, medication guides, and instruction on the product given to you. If you have any problem, seek advice from your doctor or pharmacist.

Orlistat is prescribed 3 times per day with each main meal that contains fat (no more than 30% of the calories comes from that meal). You may take medication either with your meal or 1 hour after eating your meal. If you skip a meal or your meal does not contain any fat, skip your dose for that meal.

To avoid/lessen the side effects, the fat content of your daily diet should not be higher than 30% of your total daily caloric intake. Ask Your doctor or dietitian to help you to develop a healthy eating plan.

As this drug interferes with the absorption of fat-soluble vitamins like A, D, E, K, it is recommended to use vitamin and mineral supplement when you are using this medicine. Take the multivitamin at bedtime, or at least 2 hours before or after you take orlistat.

This drug may also interfere with the absorption of cyclosporine and levothyroxine. Take cyclosporine at least 3 hours before or after orlistat and take levothyroxine at least 4 hours before or after orlistat to get full absorption of these drugs.

The weight loss is observed within two weeks after you start taking orlistat. Inform your doctor if your condition remains the same.

What are the side effects of Orlistat?

The most Common side effects with Orlistat due to its fat-blocking action are oily or fatty stools, brown colored oil in your stool, oily spotting in your undergarments, gas and oily discharge, an increased number of bowel movements, loose stools, or an urgent need to go to the bathroom, or stomach pain, nausea, rectal pain. These signs indicate that the drug is working correctly. Usually, these side effects are temporary and may get lessen with the continuous use of medicine.

Allergic reaction to this drug is very uncommon. Get emergency medical assistance right away if you observe signs of allergic reactions like difficulty in breathing, swelling of your lips, tongue, face, or throat.

Stop taking orlistat and inform your doctor at once if you have any of these side effects like symptoms of liver disease (such as persistent nausea/vomiting, dark urine, yellowing eyes/skin), signs of kidney stones (like back pain, pain when urinating, pink/bloody urine), severe stomach/abdominal pain.

This is not a full record of all possible side effects. If you notice any other effects not listed above, contact your doctor or pharmacist.

What are the precautions while using Orlistat?

Before using this drug inform your doctor and pharmacist if you are allergic to orlistat or any other medicines.

Notify your doctor or pharmacist about your medical history, mainly of digestive problem (like chronic malabsorption syndrome), gallbladder problem (like cholestasis), hypothyroidism, kidney stones (calcium oxalate kidney stones, hyperoxaluria), certain eating disorders (anorexia nervosa/bulimia), HIV infection, seizures and also, if you ever had an organ transplant surgery. Your doctor or pharmacist will advise you not to take orlistat.

Inform to your doctor, if you are taking medications that suppress the immune system like cyclosporine. In case, If you are taking cyclosporine to take it 2 hours before or 2 hours after orlistat.

Notify your doctor and pharmacist about all the products you are using like vitamins, nutritional supplements, herbal products, anticoagulants like warfarin, diabetic drugs like glipizide, glyburide, metformin, insulin. Medications to control blood pressure, medicines for thyroid disease and any other drugs for weight loss.

In diabetic patients, weight loss may raise your blood sugar levels, monitor blood sugar regularly to avoid any further complications.

This medication not to used during pregnancy inform your doctor if you are pregnant, planning to become pregnant, or are breastfeeding. Avoid taking orlistat if you are pregnant or breastfeeding.

What are the drug Interactions of Orlistat?

If your doctor has prescribed you this medication, your doctor or pharmacist may be aware of any possible drug interactions and monitoring you for them. Do not alter or stop, your dose before informing your doctor or pharmacist.

Some drugs that may interact with orlistat such as anticoagulants (like warfarin), HIV medications (like atazanavir, efavirenz, emtricitabine, lopinavir, ritonavir, tenofovir).

What are the forms and strengths of Orlistat?

Brand: Alli.
Form: Capsule.
Strengths: 60mg,

Brand: Xenical.
Form: Capsule.
Strengths: 120mg.

What is the dosage of Orlistat?

For Obesity Management:

Adults (18 to 64 years):

Prescription orlistat (Xenical): Take 120 mg orally 3 times a day with each fat-containing meal.

Over-the-Counter (Alli): Take up to 60 mg orally 3 times a day with each fat-containing meal.


Children (12 to 17 years):

Prescription orlistat (Xenical): Take 120 mg orally 3 times a day with each fat-containing meal.

Over-the-Counter (Alli): Take up to 60 mg orally 3 times a day with each fat-containing meal.

Note: In children below 12 years of age safety and efficacy have not been established yet. In patients with diabetes mellitus dose adjustment is required; monitor glycemic control closely.


TheMedPharma has made every effort to make sure that all the information is factually correct, comprehensive, and up-to-date. However, this website should not be considered as a substitute for the advice, knowledge and expertise of a licensed healthcare professional. You should always consult your doctor or licensed health care professional before taking any medication. The drug information contained herein is subjected to changes if required. The lack of warnings or other information for a given drug does not mean that the drug or its combination is safe, effective or appropriate for use in all patients.