Pyroglutamic acid (also known as PCA, 5-oxoproline, pidolic acid, or pyroglutamate for its basic form) exists as two distinct enantiomers: (2R) or D and (2S) or L. L-form is a metabolite in the glutathione cycle that is converted to glutamate by 5-oxoprolinase. L-Pyroglutamic acid is produced in the skin through the arginine-citrulline-ornitine-glutamic pathway. The free acid is not hygroscopic; however, the sodium salts of this acid are more hygroscopic than glycerine. Therefore, formulation of this acid is suggested as a defense against dehydration, for skin conditions involving desquamation. Hydromol Cream (main component of that is sodium pyrrolidone carboxylate (L form)) is a soft cream which moisturises the skin. Hydromol Cream contains a naturally occurring moisturising agent as well as oils, which prevent moisture loss from the skin. This helps to relieve itch, lubricate and soften the skin. Hydromol Cream is used to treat any condition in which dry skin is a feature such as eczema, ichthyosis (hereditary dry skin) and senile pruritus (itching that may occur in old age). L-Pyroglutamic acid is present in living cells has been reported from archaebacteria to humans, and its occurrence in living cells has been known for over a century. Despite its almost ubiquitous presence, the role of pyroglutamic acid in living cells is poorly understood. Pyroglutamic acid is found as an N-terminal modification in many neuronal peptides and hormones that also include the accumulating peptides in Alzheimer’s disease and familial dementia. The modification is also observed in proteins that include many antibodies, some enzymes and structural proteins.