Reprogram youth into your skin overnight! Skin Doctors Youthcell contains the latest plant stem cell technology (PhytoCellTec) to help delay the appearance of chronological ageing of the skin. These plant stem cells are sourced from a rare, long-living Swiss apple which has the unique ability to regenerate its cells once it falls from the tree. It is this characteristic, that when used on the skin, promotes the longevity of skin cells. Youthcell turns on the switch that tells your own skin stem cells to start producing again.