"Ceramide" refers to a broad family of molecules rather than a single molecule. Structurally, ceramides consist of a fatty acid linked to a sphingoid base. Differences in these components create different ceramide subclasses and individual ceramide species. Multiple ceramide subclasses have been identified in human stratum corneum, and modern lipidomic techniques have identified more than 1,000 individual ceramide species.³ In commonly used scientific shorthand, letters can indicate characteristics of the fatty acid and sphingoid base that make up a ceramide. Abbreviations can vary somewhat between scientific and cosmetic nomenclature systems.
Common fatty acid designations include:
• N: Non-hydroxy fatty acid
• A: Alpha-hydroxy fatty acid
• EO: Esterified omega-hydroxy fatty acid Common sphingoid bases include:
• P: Phytosphingosine
• S: Sphingosine
• DS or dS: Dihydrosphingosine, also called sphinganine
• H: 6-hydroxysphingosine
Ceramide NP
Ceramide NP pairs a non-hydroxy fatty acid with phytosphingosine and represents one of the ceramide classes naturally found in human skin.
Ceramide NG
Ceramide NG pairs a non-hydroxy fatty acid with sphinganine and represents a different ceramide class naturally found in human skin.