Glucosamine plays an important role in maintaining cartilage, and may help to relieve the pain, stiffness, and swelling of osteoarthritis. Individuals with rheumatoid arthritis and those with other types of joint injuries report improvements with glucosamine supplements. Several studies suggest that glucosamine may be as effective in easing arthritic pain and inflammation--and less irritating to the stomach--as NSAIDs (nonsteroidal anti-inflammatory drugs). Glucosamine sulfate is the form best absorbed by the body and the one most commonly used to treat osteoarthritis.