Glucosamine assists maintain the cartilage in joints healthy. But natural glucosamine levels drop as people age. This can guide to gradual deterioration of the joint. There are several confirmations that glucosamine sulfate supplements assist counteract this consequence, though experts are not sure accurately how they work. Particularly, glucosamine has been shown in several studies to assist ease the pain of mild to fair osteoarthritis of the knee. Glucosamine may also assist with other joint pain caused by osteoarthritis.