This time-released quality is proprietary technology and unique to the Advance+ Vitamin C which uses a natural enzyme system found within all mammalian cells, including humans. The enzyme system gradually and consistently removes the small carbohydrate chain from the second carbon of the molecule, leaving L-ascorbic acid (Vitamin C) for use by the skin cell. This process provides a sustained level of Vitamin C within the cell for many days and creates a natural, continuous delivery system with sustained bioavailability. With the older forms of Vitamin C, much of the Vitamin C cannot be used by the skin cell and is wasted.