Hyalgan® is a viscous solution consisting of a high molecular weight (500,000–730,000 daltons) fraction of purified natural sodium hyaluronate (Hyalectin®) in buffered physiological sodium chloride, having a pH of 6.8-7.5. The sodium hyaluronate is extracted from rooster combs. Hyaluronic acid is a natural complex sugar of the glycosaminoglycan family and is a long-chain polymer containing repeating disaccharide units of Na-glucuronate-N-acetylglucosamine.