Does glucosamine help relieve the pain of osteoarthritis? The latest research casts some doubt on the matter, suggesting that you're more likely to benefit from losing weight and doing regular exercise.
Taking glucosamine still helps some people, though. Clinical trials of pain relief in osteoarthritis consistently show a big placebo effect — this is when people feel less pain despite only taking dummy pills.
If you suffer from osteoarthritis, the chances are you’ve tried glucosamine. Many people swear by it, but does it really work? Or does it work better combined with chondroitin? And are some brands better than others?
CHOICE took a close look at the current state of the scientific evidence and tested 26 glucosamine products from supermarkets and big pharmacies.
Please note: this information was current as of May 2008 but is still a useful guide today.
What is glucosamine?
Glucosamine occurs naturally in the body, where it plays a role in the formation and repair of cartilage. The glucosamine in supplements is usually extracted from the shells of prawns and other crustaceans. There’s also 'vegetarian' glucosamine available that’s made from maize starch.
Glucosamine comes in different chemical forms, which can make it difficult to interpret labels and claims on products. The forms are:
- Glucosamine itself is the form that's active in the body, but it’s never packaged as such because it’s unstable.
- Glucosamine hydrochloride is a stable form that's used in more than half the products we tested.
- Glucosamine sulphate is the form used in tablets and capsules, but it’s only stable when combined with potassium or sodium chloride.
Glucosamine sulphate potassium chloride complex contains only 75% glucosamine sulphate. While most manufacturers make this clear on the label (at least if you read the fine print), not all do.
Two products in our assessment don't say how much glucosamine sulphate they contain, and in fact their measured dosage is not high enough to be effective. (See How much to take?)
Chondroitin sulphate also occurs naturally in the body. It’s a major component of cartilage and gives it the rubber-like characteristics that help to absorb mechanical impact on the joints from movement and activity. The chondroitin sulphate in supplements is mostly extracted from tracheas of slaughtered cattle or from pigs’ ears and snouts. Another source is shark cartilage.
There’s evidence — but it isn’t strong — that chondroitin sulphate helps relieve the pain of osteoarthritis and improve joint function. There’s also a possibility that it provides an additional benefit when glucosamine and chondroitin are taken in combination.
Osteoarthritis is a major cause of pain and disability that affects more than 1.3 million Australians. It’s a condition where there’s loss or damage of cartilage tissue in the joints, and it most commonly affects hips, knees, hands and the spine.
Wear and tear is a major cause, so older people are more likely to suffer from osteoarthritis. There’s evidence that about 50% of those over 65 have it (though not necessarily severely enough for it to be obvious).
Osteoarthritis can’t be cured (other than by replacing the affected joint with a prosthesis) but there are various things you can do to reduce its impact (see Other remedies to try), and there are medications to reduce the pain and swelling.
The medications most often prescribed are paracetamol and the non-steroidal anti-inflammatory drugs (NSAIDs) celecoxib and meloxicam.