Hyaluronic Acid is present in every tissue of the body. It is most concentrated in the synovial fluid which bathes the joints, in the vitreous fluid in the eye, and in the skin. AC-HA is the standardized natural Hyaluronic acid in sodiumsalt. It is a stable form of hyaluronic acid composed by hydrophilic molecules of glucoronic acid and N-acetyl glycosamine.