Caffeine is used in skin creams & lotions because it is a vasodilator, which means that it constricts blood cells. The benefit of caffeine for your skin is that it will reduce redness & it will firm & tighten the surface of your skin through constriction. Many companies are using this ingredient to reduce the appearance of cellulite. The caffeine in coffee when used in skin care works to dehydrate fatty cells so that water will disappear from the surface of your skin. This means that the appearance of cellulite is minimized, & your skin begins to look smoother overall.