An oily wax that make up 50% of the Stratum Corneum (the outer most layer of skin). Its presence in skin, which declines with age, is important for skin barrier function and repair and helps keep moisture in and microorganisms out. Ceramide depletion can lead to dry skin, wrinkles and dermatitis. In products, it is typically derived from plants, especially wheat germ. There are nine known types of ceramides. The name comes from the Latin word "cera" which means wax.
Since it enhances moisturization and protection of the skin, you can find ceramides in soaps, shampoos, skin creams, lotions and ointments marketed for anti aging, hydration and even to combat dermatitus.