People with osteoarthritis who take glucosamine:
- may reduce their pain
- may improve their physical function
- will probably not have side effects
What is osteoarthritis and glucosamine?
Osteoarthritis (OA) is the most common form of arthritis that can affect the hands, hips, shoulders and knees. In OA, the cartilage that protects the ends of the bones breaks down and causes pain and swelling. Drug and non-drug treatments are used to relieve pain and/or swelling.
Glucosamine can be found naturally in the body and is used by the body as one of the building blocks of cartilage. Glucosamine can also be taken as a pill as a supplement to the diet, or sometimes as an injection. It can come in combination with other supplements (such as chondroitin), or by itself in the form of glucosamine hydrochloride or sulphate. The usual dose recommended on packages is 1500 mg per day or 500 mg three times a day.
In Europe, glucosamine is prescribed by health care providers. But in North America, people can buy glucosamine supplements without a prescription. This means that, in North America, glucosamine is not regulated and the pills may or may not truly contain the amount described on the label.
Best estimate of what happens after about 6 months
Pain: The high quality studies showed that pain improved about the same whether people took glucosamine or fake pills. If all of the studies are examined (including low quality and old studies), then glucosamine improved pain more than fake pills.
People who took fake pills had a pain score of 7 points on a 0 to 100 scale. Pain may improve by 10 more points with glucosamine than with fake pills.
Studies testing only the Rotta brand of glucosamine (including low quality and older studies) showed that glucosamine improved pain more than fake pills. People who took fake pills had a pain score of 6 points on a 0 to 20 scale. People who took the Rotta brand of glucosamine rated their pain 3 points lower than people who did not take glucosamine.
Function: The high quality studies show that glucosamine improved function more than fake pills when measured by one type of scale, but improved the same amount as fake pills when measured by another scale.
Studies testing only the Rotta brand of glucosamine (including low quality and older studies) showed that glucosamine improved function more than fake pills. People who took fake pills had a function score of 22 points on a 0 to 68 scale. People who took the Rotta brand of glucosamine had their ability to function improve by 2 points compared to people who did not take glucosamine.
There was no difference in the number of people who had side effects. Side effects mainly included stomach upset and other joint pain.