Medication Information Leaflet

What is this medication for?

Orlistat is used together with dietary changes to treat obesity. It works by reducing the body’s absorption of fats. 

How should I take/use this medication?

  • Do not stop taking your medication 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 you miss a meal or your meal does not contain any 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 that contains fat. 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 medication or any of the other ingredients of this medication
  • You are pregnant, planning to become pregnant, or breastfeeding 
  • You are taking any other medications, including supplements, traditional medications and herbal remedies. 
  • You have liver or kidney problems.
  • You have chronic malabsorption syndrome, a condition where you have problems absorbing nutrients 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 experiencing side effects such as bloating or oily, fatty stools. Avoid taking fatty food between meals. 

What are some common side-effects of this medication?

  • Oily stool and/or leaking of oil from the anus
    • This is due to how the medication works.
  • Abdominal distention (enlarged or swollen abdomen), stomach pain and bloating
    • You may consider reducing your fat intake to reduce these side effects.
  • Other common side effects of orlistat include headaches, flu-like symptoms such as cough and runny nose, low blood sugar level (which may include symptoms of shakiness, dizziness, sweating), sudden or increased number of bowel movements, tiredness or irregular menstrual periods in women.
Consult your healthcare professional if the symptoms do not go away or become bothersome.

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

Consult your healthcare professional immediately if you have
  • bleeding from the anus or blood in your stool or vomit
  • dark urine or light coloured stools, nausea, vomiting, loss of appetite, stomach pain, yellowing of your eyes or skin
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 medication and see your healthcare professional immediately.

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

If you are taking any multivitamin supplement, space orlistat at least two hours before or after taking the supplement.

Inform your healthcare professional if you are taking the following medication: 
  • Anti-retroviral medications used to treat human immunodeficiency virus (HIV) infection or hepatitis B infection. 
  • Medications for seizures
  • Medications for diabetes such as Acarbose
  • Other medication such as Cyclosporin and Warfarin.

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

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.

Last updated on September 2019


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