Glucosamines are produced naturally in the body and are necessary for the repair of connective tissues and mucous membrane linings, as well as for lubrication of the joints. They can be refined from sources in nature (from Cattle, poultry as well as sea animals), and used to augment the body's own production.
Sometimes animals are deficient in glucosamine production, or the body may use up more than it produces. In arthritis, for example, the ongoind joint degeneration creates a higher demand for the body's glucosamine. Supplementation can profoundly reduce the symptoms of arthritis, as well as other diseases such as colitis and other bowel probelms, disc pain, and some bladder conditions.
Because they are natural compounds, and chmically identical to substances that occur natrually in the body, they carry very little chance of side effects.