What is Chondroitin?

Chondroitin sulfate is a naturally occurring substance in the body. It is a major constituent of cartilage—the tough, elastic connective tissue found in the joints.

Based on the evidence of preliminary double-blind studies , chondroitin is widely used as a treatment for osteoarthritis, the typical arthritis that many people suffer as they get older. However, the supporting evidence for this use is weak.

There is some evidence that chondroitin might go beyond treating symptoms and actually protect joints from damage. Current medical treatments for osteoarthritis, such as nonsteroidal anti-inflammatory drugs (NSAIDs), treat the symptoms but don't actually slow the disease's progression, and they may actually make it get worse faster. ^4,5,6,7 Chondroitin (along...

Numerous double-blind studies have found evidence that chondroitin can relieve the symptoms of osteoarthritis and possibly also slow the progression of the disease. ^{1 2 3 4 5 6 7} However, most of these studies suffer from serious problems in design, statistical analysis, and reporting. When pooled together, the results of the three best studies failed to demonstrate benefit. ⁸ On balance, the evidence for chondroitin’s effectiveness for osteoarthritis is inconsistent and incomplete. ⁹ Chondroitin has also been proposed as a treatment for other conditions, such as atherosclerosis , interstitial cystitis , and high cholesterol , but as yet the evidence that the supplement might help is far too weak to rely upon at all. ¹⁰ One small...

Safety Issues

Chondroitin generally does not cause much in the way of side effects, besides occasional mild digestive distress. However, there is one case report of an exacerbation of asthma caused by use of a glucosamine-chondroitin product. ¹¹ In addition, there are theoretical concerns that chondroitin might have a mild blood-thinning effect, based on its chemical similarity to the anticoagulant drug heparin. Reassuringly, there are no case reports of any problems relating to this, and studies suggest that chondroitin has at most a mild anticoagulant effect. ¹² Nonetheless, prudence suggests that, based on these findings, chondroitin should not be combined with blood-thinning drugs, such as warfarin (Coumadin), heparin , and aspirin , except under physician supervision. In...