Hyaluronic acid, also known as uronic acid and hyaluronic acid, is a natural polysaccharide and an important moisturizing ingredient that exists in the dermis of the human skin. Its content will decrease with age, causing dry skin and dehydration. Aging causes wrinkles, roughness, dullness and uneven skin tone. Hyaluronic acid not only has the function of maintaining the elasticity of the skin, but also can lock a large number of water molecules, and has a moisturizing and lubricating effect on the tissues.