Stratum corneum

The stratum corneum can be thought of as the “skin’s skin” since it is the outermost layer of the epidermis. It consists of dead, completely flattened, non-nucleated cells that form lamellae, or small strips. It represents the body’s ultimate barrier against the outside environment, ensuring protection from external aggression. The stratum corneum has a twofold role in keeping skin hydrated: – where the outer world is concerned, the keratinised cells of the stratum corneum form a hydrophobic barrier that prevents us from swelling up with water when we take a shower, for example; – internally, it maintains hydration thanks to its natural moisturising factor (NMF), which stops water in the skin from evaporating.