Biologique Recherche's Serum TEWL fights transepidermal water loss and restores hydration and nourishment in severe climates. Suitable for sun-damaged, leathery, very dry skin, and extreme cold conditions, it forms a lipidic shield, reversing lipid deficiency and protecting against environmental elements. Ideal for skiing or transitioning climates, it should be used with Biologique Recherche Crème Dermo-RL for optimal results.