Naturally occurring, long chains of lipids (fats) that are major components of skin’s outer layers. Skin inhibits water movement via its structure, which has a unique composition of 50% ceramides, 25% cholesterol, and 15% free fatty acids.
Ceramides are necessary for their water-retention capacity and adding them to a skincare product helps provide replenishing and restoring benefits.
Nine different ceramides have been identified in skin, some of which are used in skincare products. On a skincare product ingredient label, you’ll see those listed as ceramide AP, ceramide EOP, ceramide NG, ceramide NP, ceramide NS, phytosphingosine, and sphingosine. The ceramides used in skincare products typically are derived from plants or are synthetic; there is no research showing that either form is preferred over the other.
References for this information:
Biochimica et Biophysica Acta, October 2014, issue 10, pages 2473-2483
Journal of Lipid Research, September 2007, issue 9, pages 1936-1943
Journal of Investigative Dermatology, November 2001, issue 5, pages 1126-1136
Skin Pharmocology and Applied Skin Physiology, September-October 2001, issue 5, pages 261-271