The two nutritional supplements which are currently marketed for relief of osteoarthritic symptoms are glucosamine sulfate and chondroitin sulfate. Both are available at pharmacies and health food stores. They are not medications. People opting to take glucosamine +/- chondroitin should be aware that unlike prescription medications, there is no regulation of nutritional supplements. For this reason, there is no standard for quality or purity of the product. Different preparations may be more effective than others. It is best to ask your doctor or pharmacist which brands are most effective.
Articular cartilage acts to cushion and lubricate the knee joint. Chondroitin and glucosamine are important components of this cartilage. In osteoarthritis, cartilage is broken down (see section on osteoarthritis). It is thought that by ingesting glucosamine and chondroitin, it may be possible to restore some of the damaged cartilage and thereby offer some pain relief. Nutritional supplements are not well studied. There is some evidence that, at least in the short term, people who take these supplements have less pain and increased function. They may slow the rate of damage to the knee caused by the osteoarthritic process. Long term results are still not available. There is no evidence that these nutritional supplements will cure osteoarthritis. Both supplements appear to be safe and can be used in combination with other therapies. They are a reasonable option for people who can not tolerate NSAIDs. The most common side effect is stomach upset.
Improvement in osteoarthritic symptoms may require several weeks of regular daily therapy with glucosamine sulfate. For this reason, glucosamine should be tried for one or two months before stopping. People with an allergy to shellfish should not take glucosamine.
Chondroitin is thought to stimulate the production of articular cartilage. It is usually used in combination with glucosamine sulfate.
The article on the next page has been adapted from the American Academy of Orthopaedic Surgeons fact sheet on osteoarthritis.
To read more about osteoarthritis of the knee please visit the links section. Links have been provided to other websites as well as online medical journals. Knee injury topics can also be accessed.