Vitamin C, also called ascorbic acid, is naturally present in a large number of fruits or vegetables. In fruits (oranges, kiwis, etc.), it is a powerful antioxidant which plays an essential protective role for vital functions. Gold standard anti-ageing molecule for dermatologists, vitamin C plays an antioxidant and anti-inflammatory role. It regulates pigmentation, protects the collagen network structure, and supports synthesis of epidermal lipids to restore the skin barrier. Vitamin C is therefore an ally for tired skin as it brightens and smooths dull skin.