Hyaluronic acid (according to recent nomenclature Hyaluronan, abbreviation HA) is a glycosaminoglycan that is an important component of connective tissue and also plays a role in cell proliferation, cell migration and metastasis in some cancers. Hyaluronic acid was first discovered in the 1930s by the German physician Karl Meyer. The term hyaluronic acid is composed of the ancient Greek word hyalos (glass) and uron, an abbreviation of the uronic acids.
Hyaluronic acid is used in cosmetics. However, since the full-size hyaluronic acid is absorbed only slightly by the skin, degradation fragments of hyaluronic acid can be used. These components, called HAF, have a lower molecular weight (e.g. 50 or 130 kilodaltons), which makes it easier for the individual fragments to penetrate the skin.