Hyaluronic acid is also known as hyaluronic acid. Hyaluronic acid exists in the human body and has the functions of lubricating joints and moisturizing the skin. The skin also contains a large amount of hyaluronic acid. The process of human skin maturation and aging also changes with the content and metabolism of hyaluronic acid. It can improve the nutrition metabolism of the skin, make the skin soft, smooth, wrinkle removing, increase elasticity and prevent aging. While moisturizing, it is also a good transdermal absorption promoter. Small molecules of hyaluronic acid can be used to replenish water. Medium – and macromolecular hyaluronic acid is clinically used to fill depressions and adjust facial contours