Naturally occurring, long chains of lipids (fats) that are major components of skin’s outer layers. Skin inhibits water movement and controls loss 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 (wheat germ is a common source) or are synthetic; there’s no research showing that either form is preferred over the other.
Ceramides work best for skin when they’re combined with other replenishing ingredients like fatty acids and cholesterol. These lipid mixtures work in multiple ways to improve skin’s texture, suppleness, and help calm signs of sensitivity.
References for this information:
Biochimica et Biophysica Acta, October 2014, pages 2473-2483
Journal of the American Academy of Dermatology, July 2014, pages 177-184
Journal of Lipid Research, September 2007, pages 1936-1943
American Journal of Clinical Dermatology, Volume 4, 2003, pages 107-129
Journal of Investigative Dermatology, November 2001, pages 1126-1136
Skin Pharmocology and Applied Skin Physiology, September-October 2001, pages 261-271