Hyaluronic acid is a natural polysaccharide which is in the class of glycosaminoglycans that is mostly found in neural, connective and epithelial tissues in human body.
Hyaluronic acid is made up repeating units of glucuronic acid and N-acetylglucosamine that are joined by alternating β- 1,4 and β- 1,3 glycosidic bonds.
It is a linear polysaccharide and is the only glycosaminoglycan that lacks sulfate atoms in its structure.