Medicines & Supplements A to Z > Orlistat


Last updated on 30/07/2021.

Overview   |   Dosage   |    Side Effects   |   Precautions  |   Tips  |   Where To Buy  




DRUG CLASS: Lipid-regulating Drugs

SUB CLASS: Lipase inhibitors

USED FOR: Weight loss

– 60mg, 120mg (capsules)

What is Orlistat for?

Orlistat belongs to a class of medications called lipase inhibitors, which can reduce absorption of fat from diet. It is used as an obesity-management medication for severely obese patients (BMI ≥ 30 kg/m2 or ≥ 27 kg/m2 with co-morbidities, such as hypertension, diabetes, dyslipidemia). It is especially useful for patients with a high fat diet.

How to use it?

Orlistat is taken orally as capsules. 

Orlistat 120 mg-formulation:
120 mg three times daily, with meals.

Orlistat 60 mg-formulation:
60 mg three times daily, with meals.

What are the side effects of Orlistat?

Common side effects of Orlistat include headache, influenza, back pain, flatulence with discharge, fatty/oily stools, increased defecation, upper respiratory tract infection, and abdominal discomfort.

Who should not take Orlistat?

– People allergic to Orlistat or any component of the formulation
– Patients with cholestasis or chronic malabsorption syndrome

Pharmacist Tips:

– Because the absorption of fat soluble vitamins (i.e. Vitamins A, D, E and K) could be affected, it is recommended to take a multivitamin containing fat-soluble vitamins to ensure adequate nutrition.
– Lifestyle modifications are as important as medications in weight management, such as a balanced diet and regular exercise.
– If you have diabetes and are taking antidiabetic drugs, please consult your doctor or pharmacist before using Orlistat because dose modification may be required. 

Common dosing schedule:
Orlistat should be administered during or up to 1 hour after each main meal containing fat. Dose can be omitted if a meal is missed or contains no fat.

Also, separate doses by at least 2 hours from multivitamins containing fat-soluble vitamins.

If used concurrently with Orlistat, you should take Levothyroxine at least 4 hours before or 4 hours after the Orlistat dose. 

This schedule is for reference only, adjustments may be made according to individual needs.

Some common medications Orlistat may interact with:
– Anticonvulsants, e.g. Phenytoin, Carbamazepine
– Antiretrovirals, e.g. Tenofovir, Ritonavir

Please notify your doctor or pharmacist if you are taking the above medication, dosage adjustments might be needed.

Where to buy Orlistat in Hong Kong?

In Hong Kong, Orlistat 60 mg is a medicine under supervised sales and can be purchased under the supervision of a pharmacist from any pharmacies in Hong Kong. Orlistat 120 mg is a prescription drug. It can be obtained from doctors. To find a pharmacy near you, refer to the list of pharmacies (“Authorized Sellers of Poisons”) from the Hong Kong Department of Health.

For more information about drug names and ingredients, you can visit Hong Kong’s Drug Office at

Need more information?

For detailed information about the use of Orlistat in children, pregnancy and breastfeeding, and for questions about drug interactions, please check with your pharmacist or doctor.

Disclaimer: our goal is to provide you with the most relevant drug information and common dosage for Hong Kong. This information does not constitute medical advice. For specific treatment recommendations and advice, always discuss with your doctor or pharmacist, and follow the instructions included with your specific medicine.