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 natural health products. Glucosamine may be taken separately as a 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 looking at glucosamine or chondroitin for osteoarthritis in the hip or knee did not show that these supplements slow joint destruction or relieve pain.footnote 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 will not help you more than a placebo. Talk to your doctor if you 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 and Non-Prescription Health Products Directorate (NNHPD), within the Health Products and Food Branch of Health Canada, regulates natural health products in Canada. Natural health products, including glucosamine and chondroitin, must be reviewed and approved by the NNHPD before they can be sold in Canada.
Always tell your doctor if you are using a natural health product or if you are thinking about combining a natural health product with your conventional medical treatment. It may not be safe to forgo your conventional medical treatment and rely only on a natural health product. This is especially important for women who are pregnant or breastfeeding.
When using natural health products, keep in mind the following:
- Like conventional medicines, natural health products may cause side effects, trigger allergic reactions, or interact with prescription and non-prescription medicines or other natural health products you might be taking. A side effect or interaction with another medicine or supplement may make other health conditions worse.
- The way natural health products 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 natural health products are not known.
- 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
- Chondroitin (2015). Facts and Comparisons eAnswers. http://online.factsandcomparisons.com/MonoDisp.aspx?monoID=fandc-np5090&quick=-316792%7c20&search=-316792%7c20&isstemmed=True&NDCmapping=-1&fromTop=true. Accessed April 28, 2016.
- 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.
- Drugs for osteoarthritis (2014). Medical Letter on Drugs and Therapeutics, 56(1540): 80–84. http://secure.medicalletter.org/system/files/private/TML-article-1450b.pdf. Accessed April 28, 2016.
- Glucosamine (2012). In A DerMarderosian et al., eds., Review of Natural Products. St. Louis: Wolters Kluwer Health.
- Government of Canada (2014). There are rarely reasons not to breastfeed. Breastfeeding and Infant Nutrition . https://www.canada.ca/en/public-health/services/health-promotion/childhood-adolescence/stages-childhood/infancy-birth-two-years/breastfeeding-infant-nutrition.html. Accessed February 1, 2018.
- Scott D (2009). Osteoarthritis of the hip, search date May 2007. Online version of BMJ Clinical Evidence: http://www.clinicalevidence.com.
- Scott D, Kowalczyk A (2007). Osteoarthritis of the knee, search date October 2006. Online version of BMJ Clinical Evidence: http://www.clinicalevidence.com.
Current as of: December 9, 2019
Author: Healthwise Staff
Medical Review: Anne C. Poinier MD - Internal Medicine
Brian D. O'Brien MD - Internal Medicine
Adam Husney MD - Family Medicine
Martin J. Gabica MD - Family Medicine
Kathleen Romito MD - Family Medicine
Stanford M. Shoor MD - Rheumatology
Current as of: December 9, 2019