Luminosity and hydration thanks to plants | The ideal solution for radiant skin. Youth To The People 15% Vitamin C + Caffeine Energy Serum is a brightening vitamin C serum enhanced with plant-based caffeine from yerba mate and guayusa super leaves to instantly brighten, visibly reduce morning puffiness and hydrate skin. Contains 15% vitamin C complex to give skin a boost of energy, enhanced by its refreshing natural plant-based scent.