This is a light water-based emulsion that can be used under day/night moisturizers to give added hydration to dehydrated skin. Its main ingredient is hyaluronic acid which is extremely hydrating to the skin without being heavy. It also can be used safely under benzoyl peroxide and still allow benzoyl peroxide to penetrate the pore. Most moisturizers will occlude the action of benzoyl peroxide thus preventing it from working. 2 fl oz.