Unlock Exclusive Discounts & Flash Sales! Click Here to Join the Deals on Every Wednesday!
The stratum corneum (SC) acts as a protective layer between the highly hydrated viable epidermis and the relatively dry environment; thus it normally sustains a water activity gradient. The water content of SC is a function of relative humidity of the environment, SC barrier properties, and the presence of natural moisturizing factors (NMF). Skin hydration not only affects the barrier properties, but also affects the enzymatic activity in SC.