Naturally occurring, long chains of lipids (fats) which are important components in the outer layer of the skin. Ceramides are natural lipids / fats that bind skin cells together and act as a shield on the outside of the skin. The body produces this naturally, but with a number of skin problems, the skin produces fewer ceramides. This leads to a weakened skin barrier and a membrane that does not work properly. This in turn can leave a skin feeling rough and irritated because it is dry.