Kondroitiini

Kondroitiini, also known as chondroitin sulfate, is a sulfated glycosaminoglycan that occurs naturally in the cartilage of animals. It is composed of repeating disaccharide units of D-glucuronic acid and N-acetylgalactosamine, with varying patterns and degrees of sulfation. Sources include animal cartilage (bovine, porcine, or shark) and, more recently, production by bacterial fermentation. In the extracellular matrix, chondroitin sulfate is covalently attached to core proteins to form proteoglycan aggregates, contributing to the resilience and load-bearing properties of cartilage and influencing tissue hydration.

Chondroitin sulfate is widely used as an oral dietary supplement for osteoarthritis and is sometimes prescribed in combination with glucosamine. Typical over-the-counter products provide about 800 to 1200 mg of chondroitin sulfate daily. Regulatory status varies by country; in many places it is treated as a dietary supplement rather than a drug, with labeling requirements but no premarket efficacy demonstration.

Clinical evidence regarding efficacy for osteoarthritis is mixed. Some randomized trials and meta-analyses report small improvements in pain and function, while others find benefits that are not clinically meaningful or not consistently replicated. There is no robust evidence that chondroitin slows structural progression of OA in all patients, and responses may be heterogeneous.

Safety and quality considerations are important. Chondroitin is generally well tolerated, with occasional gastrointestinal symptoms or allergic reactions. Potential drug interactions, notably with anticoagulants, may affect bleeding risk. Product quality can vary, and there have been historical concerns about contamination and mislabeling, underscoring the importance of quality-controlled sources.