Sodium L-PCA (Nalidone) is naturally present in the NMF (Natural Moisturizing Factor). The function of the NMF is to provide, to restore and to maintain an optimum condition of hydration in the stratum corneum. Sodium L-PCA is one of the major components of the NMF as it is present at 14%. Nalidone can be thus considered as the physiological moisturizer of epidermis above all else.