Glucosamine (C 6 H 13 NO 5) is an amino sugar and a prominent precursor in the biochemical synthesis of glycosylated proteins and lipids. Glucosamine is part of the structure of two polysaccharides, chitosan and chitin.

Glucosamine is a chemical compound that occurs naturally in both human and animal tissues. In humans, it helps form cartilage and is commonly used as a dietary supplement to treat joint disorders like osteoarthritis. Glucosamine is often used supplementally to treat symptoms of various inflammatory conditions.