Medication Information Leaflet

What is this medication for?

Orlistat is used together with dietary changes to treat obesity.

How should I take/use this medication?

  • Do not stop taking your medicine or exceed the prescribed dose without checking with your healthcare professional.
  • Take the medication with water immediately before, during or up to one hour after each main meal that contains fat. If a meal is missed or contains no fat, you do not have to take the medication.

What should I do if I forget to take/use this medication?

If you miss a dose, take it as soon as you remember if it is within one hour after your last main meal. Take your next dose at the usual time. Do not take two doses to make up for the missed dose.

What precautions should I take?

Inform your healthcare professional if: 
  • You are allergic to this medicine or any of the other ingredients of this medicine.
  • You are pregnant, planning to become pregnant, or breastfeeding.
  • You are taking any other medicines, including supplements, traditional medicines and herbal remedies.
  • You have liver or kidney problems.
  • You have chronic malabsorption syndrome, a condition where you have problems absorbing nutrition from food.
  • You have cholestasis, a condition where the flow of bile from the liver is blocked
  • You have diabetes.     
This medication may reduce the absorption of fat soluble vitamins (A, D, E, K) and can cause low vitamin levels in rare cases, if taken continuously for a long time. You can take vitamin supplements that contain vitamin A, D, E and K to make sure you get enough nutrition.

You should eat a well-balanced diet and split your fat intake evenly over your three main meals. To find out more about planning a well-balanced diet, talk to your healthcare professional or dietitian.

Taking orlistat with a meal that contains a lot of fat may increase your chance of side effects such as bloating or oily, fatty stools. Avoid taking fatty food between meals.

What are some side-effects that I need to seek medical advice immediately?

The symptoms of a drug allergy include one or more of the following:
  • Swollen face/eyes/lips/tongue
  • Difficulty in breathing
  • Itchy skin rashes over your whole body

If you experience any of these symptoms, you should stop your medicine and see your healthcare professional immediately.
  • Yellowing of your eyes and skin
  • Dark urine
  • Light-coloured stools
  • Loss of appetite
  • Bleeding at the anal area (including blackened stools) or blood-stained vomit

What are some other side-effects of this medication?

Oily stool and/or oily leakage from the rectum.
  • This occurs due to the normal mechanism of this medicine. However, should symptoms persist and cause significant discomfort, consult your healthcare professional.
May cause abdominal distention (enlarged or swollen abdomen) and stomach pain and bloating.
  • This may be minimized by reducing fat intake, but if this is persistent or causes significant discomfort, consult your healthcare professional.
Other common side effects of orlistat include headaches, flu-like symptoms, low blood sugar level (which may include symptoms of shakiness, dizziness, sweating). Sudden or increased number of bowel movements, tiredness, irregular menstrual periods.

If symptoms do not go away or cause significant discomfort, consult your healthcare professional.

What food or medication should I avoid when I take this medication?

  • If a multivitamin supplement is required, orlistat should be taken at least two hours before or after the supplement.
Inform your doctor if you are taking:
  • Medicine for seizures
  • Medicines for the treatment of human immunodeficiency virus (HIV) infection and hepatitis B)
  • Ciclosporin
  • Warfarin
  • Acarbose

How should I store this medication?

Store in a cool and dry place, away from direct sunlight. Keep this medication away from children. 

How should I throw away this medication safely?

Pack this medicine into a black trash bag and seal it tightly before throwing into the rubbish chute or bin.

Please take note that the above is not a complete list of all possible side effects. If you have any concerns about your medication or if you have other side effects that you think are caused by this medication, please consult your doctor or pharmacist.

If you take more than the recommended dose, please seek medical advice immediately. The information provided on this page does not replace information from your healthcare professional. Please consult your healthcare professional for more information.

This article is jointly developed by members of the National Medication Information workgroup. The workgroup consists of cluster partners (National Healthcare Group, National University Health System and SingHealth), community pharmacies (Guardian, Unity and Watsons) and Pharmaceutical Society of Singapore. The content does not reflect drug availability and supply information in pharmacies and healthcare institutions. You are advised to check with the respective institutions for such information.

Last updated on September 2022

Back to Top