Glucosamine is the main molecule used by the body for building cartilage. Glucosamine supplements, alone or in combination with chondroitin or MSM, have been studied and shown to reduce joint pain and to improve joint function. Chondroitin is present in cartilage and connective tissue. It helps attract fluid to lubricate and cushion joints; MSM is a naturally occurring sulphur compound found in our bodies to relieve joint pain associated with osteoarthritis.