If you have osteoarthritis, youve probably heard of glucosamine and chondroitin. You may be considering taking these supplements, or perhaps you already take them. Because they are supplements you do not need a prescription. But should you take them? Glucosamine and chondroitin are naturally occurring substances in the body. Glucosamine is found in cartilage, where it helps in the formation and repair of cartilage. Chondroitin is a component of cartilage that helps cartilage to retain water. Its thought that taking supplements containing these substances may help relieve joint pain.