N-Stearoyl-phytosphingosine is also known as ceramide 3. All ceramides contain sphingosine or phytosphingosine as their building block which is linked with nonhydroxy-, ω-hydroxy-, or ω-hydroxyacids with amide bonds. Phytosphingosine type of ceramide is divided into ceramide 3 and 7. Ceramide 3 contains phytosphingosine backbone linked with fatty acid of chain length between 18 and 24 carbons, in an acyl linkage. Ceramide 3 class contains the members- ceramide 3 and ceramide 3b. Ceramide 3 contains stearic acid as the side chain.

N-Stearoyl phytosphingosine is an intercellular lipid that has been found to inhibit the expression of the allergic cytokines, IL-4 and TNF-alpha.

Stratum corneum (SC), the uppermost layer of the epidermis, is composed of seven different types of cermaides. They are present in the continuous lipid phase between SC cells, which also includes cholesterol and free fatty acids. It is thought that the varying type of ceramide constitution in skin determines the physiological function of SC. They also determine the lipid barrier structuring of the skin, where ceramide 3 forms a nearly water-impermeable lipid film.