Glucosamine and Chondroitin

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Glucosamine and Chondroitin

Topic Overview

What are glucosamine and chondroitin?

Glucosamine and chondroitin are part of normal cartilage. Cartilage acts as a cushion between the bones in a joint.

Glucosamine, also called chitosamine, is a natural substance that is found in the covering of shellfish. It is available in different forms, including glucosamine hydrochloride, N-acetyl-glucosamine (NAG), and glucosamine sulfate, which is a combination of glucosamine and mineral salt. Glucosamine is also available in synthetic forms. The body absorbs glucosamine well.

Chondroitin can come from natural sources, such as shark or bovine cartilage, or it can be made in a lab. Chondroitin is also known as chondroitin sulfate, chondroitin sulfuric acid, and chonsurid. Chondroitin sulfate is a combination of chondroitin and mineral salt.

Glucosamine and chondroitin are available in tablet, capsule, powder, or liquid form and are often taken in combination with each other or in combination with other dietary supplements. Glucosamine may be taken separately as a dietary supplement for joints.

What are glucosamine and chondroitin used for?

Many people take glucosamine and chondroitin, alone or together, for osteoarthritis. Some people believe this helps. But an analysis of studies did not show that these supplements slow joint destruction or relieve pain.1

Are glucosamine and chondroitin safe?

It appears that glucosamine and chondroitin, alone or together, are safe and have few side effects. But they cost money and may not help you. Talk to your doctor if your are thinking about taking glucosamine and chondroitin.

If you are allergic to shellfish, do not take glucosamine unless you have talked to your doctor. Some glucosamine is made from shellfish covering.

The Natural Health Products Directorate (NHPD), within the Health Products and Food Branch of Health Canada, regulates dietary supplements in Canada. Dietary supplements, including glucosamine and chondroitin, must be reviewed and approved by the NHPD before they can be sold in Canada.

Always tell your doctor if you are using a dietary supplement or if you are thinking about combining a dietary supplement with your conventional medical treatment. It may not be safe to forgo your conventional medical treatment and rely only on a dietary supplement. This is especially important for women who are pregnant or breast-feeding.

When using dietary supplements, keep in mind the following:

  • Like conventional medicines, dietary supplements may cause side effects, trigger allergic reactions, or interact with prescription and non-prescription medicines or other supplements you might be taking. A side effect or interaction with another medicine or supplement may make other health conditions worse.
  • The way dietary supplements are manufactured may not be standardized. Because of this, how well they work or any side effects they cause may differ among brands or even within different lots of the same brand. The form of supplement that you buy in health food or grocery stores may not be the same as the form used in research.
  • Other than for vitamins and minerals, the long-term effects of most dietary supplements are not known.

References

Citations

  1. Wandel S, et al. (2010). Effects of glucosamine, chondroitin, or placebo in patients with osteoarthritis of the hip or knee: Network meta-analysis. BMJ. Published online September 16, 2010 (doi:10.1136/bmj.c4675).

Other Works Consulted

  • Chard J, et al. (2006). Osteoarthritis of the hip, search date October 2005. Online version of Clinical Evidence (15): 1–12.
  • Chondroitin (2004). In A DerMarderosian, J Beutler, eds., Review of Natural Products. St. Louis: Wolters Kluwer Health.
  • Murray MT, Bongiorno PB (2006). Osteoarthritis. In JE Pizzorno Jr, MT Murray, eds., Textbook of Natural Medicine, 3rd ed., pp. 1961–1975. Edinburgh: Churchill Livingstone.
  • Murray MT, Pizzorno JE Jr (2006). Glucosamine. In JE Pizzorno Jr, MT Murray, eds., Textbook of Natural Medicine, 3rd ed., pp. 987–992. Edinburgh: Churchill Livingstone.
  • Clegg DO, et al. (2006). Glucosamine, chondroitin sulfate, and the two in combination for painful knee osteoarthritis. New England Journal of Medicine, 354(8): 795–808.
  • Glucosamine (2007). In A DerMarderosian, JA Beutler, eds., Review of Natural Products. St. Louis, MO: Wolters Kluwer Health.
  • Glucosamine for osteoarthritis (2001). Medical Letter on Drugs and Therapeutics, 43(1120): 111–112.
  • Scott D, Kowalczyk A (2007). Osteoarthritis of the knee, search date October 2006. Online version of BMJ Clinical Evidence: http://www.clinicalevidence.com.

Credits

By Healthwise Staff
Primary Medical Reviewer Anne C. Poinier, MD - Internal Medicine
Primary Medical Reviewer Andrew Swan, MD, CCFP, FCFP - Family Medicine
Specialist Medical Reviewer Stanford M. Shoor, MD - Rheumatology
Last Revised June 6, 2011

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