Caffeine, derived from the coffee plant, is used in skincare as an antioxidant and a vasoconstricting agent. Its antioxidant properties help to protect against free radicals, neutralising them before they can cause damage to the skin cells. Its vasoconstricting abilities make it good for draining water retention from around the eye area, to reduce puff, and for reducing skin redness by constricting the capillaries whose dilation visually increases skin redness by passing blood closer to the skin’s surface.