Glucosamine is marketed for use in osteoarthritis to relieve pain and improve joint mobility.

What is glucosamine?

Glucosamine is a type of sugar made naturally by the body. It helps in the formation and repair of cartilage in joints. Cartilage is the slippery, shock absorbing tissue that covers the ends of bones in a joint. It allows the bones to move smoothly against each other.

Oral manufactured supplements containing glucosamine are often marketed for use in osteoarthritis to relieve pain and improve joint mobility. 

Can you measure glucosamine levels?

No, it’s not possible to measure your body’s glucosamine levels. See your doctor if you have symptoms of osteoarthritis. Your doctor can diagnose if it is osteoarthritis or if it’s another condition such as rheumatoid arthritis.

What glucosamine supplements are available in Aotearoa New Zealand?

  • You can find glucosamine supplements in pharmacies, health shops and supermarkets.
  • Supplements can be found as tablets, capsules and liquid formulations with or without the supplement chondroitin.
  • They are available in two different salt forms – glucosamine sulphate and glucosamine hydrochloride.
  • The glucosamine in manufactured supplements is usually made from shellfish such as crab, lobster or shrimp shells, but some supplements are made from a plant form of glucosamine.
  • In Aotearoa New Zealand glucosamine is not registered as a medicine but is considered a health supplement.
  • If you are considering taking supplements, get advice from your pharmacist or doctor first. Read the manufacturer's instructions for the dose you need to take and any special instructions.

Do glucosamine supplements work?

It is not clear if glucosamine supplements are useful for symptoms or joint structure of osteoarthritis. Overall, there is little evidence of benefit. Glucosamine supplements are not specifically recommended for the treatment of osteoarthritis.

However, many patients use these supplements and report beneficial effects. Some find benefits after 3–6 months. Some trials show a small benefit after 2–3 years of use, other trials show no benefit.

The evidence shows that glucosamine sulphate is more effective than glucosamine hydrochloride. If glucosamide is taken, a dose of 1500 mg daily may be tried but should be stopped if there is no improvement after 3 months.

What are the side effects of glucosamine?

Glucosamine is not known to cause any major side effects. Common mild side effects include:

  • nausea (feeling sick)
  • indigestion, stomach upset
  • stomach pain or cramps
  • diarrhoea (runny poo)
  • drowsiness
  • headache
  • tiredness.

Since glucosamine supplements can be made from shellfish, people with seafood allergies should avoid taking them. 

Glucosamine can affect the way your body handles sugar, especially if you have diabetes or other blood glucose problems, such as insulin resistance or impaired glucose tolerance. 

Did you know that you can report a side effect to a medicine to CARM (Centre for Adverse Reactions Monitoring)? Report a side effect to a product


Glucosamine supplements interact with the anticoagulant medicine warfarin. Ask your doctor or pharmacist to check for any medication interactions before you consider taking glucosamine supplements.

Learn more

Complementary therapies and products Arthritis New Zealand
Glucosamine and chondroitin Arthritis Australia
Glucosamine Patient Info, UK
Glucosamine & chrondroitin factsheet OrthoInfo American Academy Orthopaedic Surgeons, US


Credits: Sandra Ponen, Pharmacist. Reviewed By: Maya Patel, MPharm PGDipClinPharm, Auckland Last reviewed: 27 Jan 2022