Hyaluronic Acid (HA)

See Sodium Hyaluronate (Section 51). A glycosaminoglycan naturally present in high concentrations in synovial fluid, the vitreous humor of the eye, and the dermis of the skin. In supplement contexts, it is supplied as sodium hyaluronate (the sodium salt form). The terms "hyaluronic acid" and "sodium hyaluronate" are often used interchangeably in consumer-facing product descriptions, though they are chemically distinct (free acid vs sodium salt).