Chondroitin

Chondroitin, or chondroitin sulfate, is a sulfated glycosaminoglycan that is a major structural component of cartilage and other connective tissues. It consists of repeating disaccharide units of N-acetylgalactosamine and glucuronic acid, variably sulfated. In cartilage, chondroitin sulfate is attached to proteoglycans, contributing to the tissue’s resilience, lubrication, and ability to retain water.

Commercial chondroitin sulfate is typically derived from animal cartilage, such as bovine, porcine, or shark tissues, and is sold as a dietary supplement or pharmaceutical ingredient. The product is often derived from cartilage waste and undergoes purification and standardization to specified sulfate content.

Usage and evidence: Chondroitin sulfate is used as a supplement for osteoarthritis and other joint conditions, frequently in combination with glucosamine. Randomized trials show small, variable improvements in pain and function for some patients, but overall effects are modest and not consistently seen across studies. Several reviews note methodological limitations and advise that benefits may not justify widespread use for all patients. Guidelines vary by country.

Mechanism: Proposed actions include modulation of cartilage matrix metabolism, anti-inflammatory effects, and maintenance of cartilage-water content, though exact mechanisms are not fully established.

Safety and regulation: Chondroitin is generally well tolerated; common side effects include gastrointestinal symptoms and, rarely, allergic reactions. It may interact with anticoagulants and should be used with caution in shellfish allergy or pregnancy. As a dietary supplement, product quality and labeling can vary, and some jurisdictions require quality testing.

See also: Glucosamine; Hyaluronic acid.