Oral glucosamine is commonly used for the treatment of osteoarthritis. Glucosamine is naturally present in the shells of shellfish and animal bones and bone marrow. It is a popular alternative medicine aimed to prevent cartilage degeneration and treat arthritis.

Glucosamine supplement builds cushion in the joints. It has been found to rebuild damaged joints, restore function and reduce pain. Its use as a therapy for osteoarthritis appears safe, but there is conflicting evidence as to its efficacy. Since glucosamine is usually derived from shellfish, those allergic to shellfish may wish to avoid it. Another concern is that glucosamine can affect insulin levels so diabetics need to be closely watched by a doctor if they take glucosamine