Glucosamine, which is produced naturally in the body, plays a key role in building cartilage; the tough connective tissue that cushions the joints.
Glucosamine reduces pain of osteoarthritis in the knee about as well as the over-the-counter pain reliever acetaminophen (Tylenol). It also seems to reduce pain about as much as the nonsteroidal anti-inflammatory drugs
Taking 1000 mg of glucosamine sulfate by mouth daily for 6 months might reduce the relapse of multiple sclerosis.
Glucosamine has also been used to try and relieve rheumatoid arthritis and other conditions, such as inflammatory bowel disease, asthma, allergies, chronic venous insufficiency, sports injuries, temporomandibular joint problems and chronic low back pain.