Ceramides are lipid molecules that are found naturally in high concentrations in the uppermost layers of skin. In addition to keeping the skin plump, ceramides help hold skin together by forming a protective layer and barrier that limits moisture loss and protects against visible damage from pollution and other environmental stressors. 

Also, ceramides strengthen the integrity of the uppermost layers of the skin. ⁠When found in products, ceramides restore natural lipids and capture & retain water that the epidermis needs in order to stay supple, smooth and moisturized = younger-looking skin that is functionally more healthy. ⁠