Glucosamine is a monosaccharide, which is naturally produced in the body from glucose and glutamine. This substance is a precursor of glycosaminoglycans and proteoglycans, which are essential to the synthesis of connective tissue components and crucial to maintaining and renewing the health of tissues that make up the cartilage and joints. There are no food sources of glucosamine, so this substance must be obtained exclusively through the use of dietary supplements. These supplements are produced from the exoskeleton of shellfish (shrimp, lobsters and crabs). This is essential for maintaining and renewing the connective tissues that make up cartilage. This monosaccharide inhibits enzymes that lead to degradation of chondrocytes, which means it increases the concentration of these cells.