Chondroitin sulfate is a sulfated glycosaminoglycan (GAG) composed of a chain of alternating sugars (N-acetylgalactosamine and glucuronic acid). It is usually found attached to proteins as part of a proteoglycan. A chondroitin chain can have over 100 individual sugars, each of which can be sulfated in variable positions and quantities. Chondroitin sulfate is an important structural component of cartilage and provides much of its resistance to compression.Along with glucosamine, chondroitin sulfate has become a widely used dietary supplement for treatment of osteoarthritis.
Chondroitin is in dietary supplements used as an alternative medicine to treat osteoarthritis and also approved and regulated as a symptomatic slow-acting drug for this disease (SYSADOA) in Europe and some other countries. It is commonly sold together with glucosamine. Chondroitin and glucosamine are also used in veterinary medicine.
Chondroitin, along with commonly used glucosamine, should not be used to treat patients who have symptomatic osteoarthritis of the knee as evidence shows that these treatments fail to provide relief for that condition
Clinical studies have not identified any significant side effects or overdoses of chondroitin sulfate, which suggest its long-term safety.The Task Force of the European League Against Rheumatism (EULAR) committee recently granted chondroitin sulfate a level of toxicity of 6 in a 0-100 scale, confirming it is one of the safest drugs for osteoarthritis. Moreover, its safety is supported by an absence of drug-drug interactions (chondroitin sulfate is not metabolized by cytochrome P450),and the lack of safe alternatives for patients multi-medicated for osteoarthritis and other accompanying diseases, e.g. diabetes, hypertension, hyperlipidemia, etc.