Healthy, beautiful skin looks and feels glowing and supple because the tissues can gracefully accept and retain moisture. One of the most important aspects that allows the skin to keep a natural balance of hydration is the skin barrier function, the natural regulation system that determines how much and how quickly moisture can be absorbed into the skin tissues and is prevented from being lost. Ceramide, one of three types of lipids in skin tissue, is thought to play an essential role in maintaining the water permeability function of skin, particularly by helping prevent loss of moisture.