What is Hyaluronic Acid (HA)? Hyaluronic acid also exists naturally in our bodies and its most important function is to carry and bind water . Hyaluronic acid is a polysaccharide and is one of very few stubstances that it is identical in all species and tissue types. It plays an important role giving volume to the skin, shape to the eyes and elasticity to the joints. It can be found in the eyes, tendons, articulations, and above all in the dermis of the skin. With the years our skin produces less hyaluronic acid, which is the result of normal aging process. Your skin becomes thinner and as a result, it becomes loose and starts to wrinkle.