Karl Meyer and his assistant John Palmer first found hyaluronic acid (HA), a biopolysaccharide with a high molecular weight, in the vitreous of cows' eyes in 1934. In addition to humans, microorganisms have major biological uses for hyaluronic acid. This review discusses hyaluronic acid's clinical applications, basic pharmacological properties, various physiological and pathological activities, and metabolisms. In addition to being present in most connective tissues, it is notably concentrated in umbilical cords, chicken combs, synovial fluid, and the vitreous fluid of the eye. Hyaluronan synthases, a type of integral membrane proteins, produce it in nature, while hyaluronidases are the enzymes that break it down.

Keywords : History, Metabolism, Toxicity, Properties, Structure, Application.