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Chitosan (Supplement)

Used for: Weight loss, Reduction of high cholesterol levels
Chinese name:

What is Chitosan for?

Chitosan is a polysaccharide derived from chitin. It has been suggested that chitosan binds dietary fat in your intestines. When ingested, like other fibres, Chitosan will swell in the stomach and intestines which gives a sense of fullness and may reduce your appetite. Hence, Chitosan is commonly used as a supplement for weight management as well as for reducing cholesterol levels.


However, there is limited scientific evidence showing that Chitosan is effective.

How to use it?

Chitosan supplements are available in oral dosage forms like tablets and capsules. You should take Chitosan supplements with meals. The usual doses are 3-4.8 g daily in divided doses. For specific dosages, refer to the product label.

What are the side effects of Chitosan?

The side effects of taking the Chitosan supplement are mainly constipation, stomach pain, flatulence, heartburn, and malabsorption of fat-soluble vitamins (e.g. Vitamin A, Vitamin D, Vitamin E and K). You should avoid taking Chitosan if you are allergic to seafood since it is produced from the shells of sea crustaceans.

Who should not take Chitosan?

As Chitosan is derived from shellfish, people who are allergic to seafood, especially shellfish, may be allergic to Chitosan as well and should avoid taking Chitosan supplements.

Pharmacist Tips:

  • As Chitosan is suggested to reduce dietary fat absorption, long-term intake of this supplement may affect the absorption of other fat-soluble vitamins. You are advised to take multivitamins in this case.

Common dosing schedule: 
Take Chitosan supplements as per product instructions.


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


Some common medications Chitosan may interact with:

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

Where to buy Chitosan in Hong Kong?

In Hong Kong, Chitosan supplements can be purchased without a prescription from any retail outlet in Hong Kong. This includes grocery stores, convenience stores, medicine shops, and pharmacies. It can also 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 https://www.drugoffice.gov.hk

Need more information?

For detailed information about the use of Chitosan (Supplement) 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.

Brands in Hong Kong
Now Foods
Available dosage
  • 500mg (Capsules)
Drug class
Sub class
Other drugs in same class
Used for: Osteoarthritis, Joint health
Chinese name: