Purple rice extract works synergistically with liquorice root extract (scientifically known as dipotassium glycyrrhizate) as an inhibitor of the enzyme hyaluronidase. SkinCeuticals H.A. Intensifier uses purple rice and licorice root extract together to turn off the hyaluronidase enzyme. Consequently, with continued use of this serum, the skin’s store of hyaluronic acid increases in the skin structure, giving you the plumper skin of youth, increased firmness and a smoother texture, especially concerning the improvement of marionette lines and nasolabial folds.