Phytosphingosine is a type of lipid which occurs naturally in the stratum corneum layer of the skin. It is found in its free form or as a part of ceramides in the upper layers of the skin.  Phytosphingosine is a type of lipid which makes up the lipid barrier of the skin. It can be considered as a base molecule for ceramide molecules. For more information on phytosphingosine uses please see Ceramides.