Hyaluronic acid (HA) is a molecule that is naturally present in the human body and in particular the skin. It enables, among other things, regultation of the hydration and reconstruction of the skin’s connective tissue structure, but it decreases with age. Used in cosmetic medcine, synthesized hyaluronic acid is a biodegradable product enabling the maintenence of good skin hydration and volume. It is safe, completely resorbable and it provides very natural effects.