The evidence-based dermatology take on skin barrier repair — what the stratum corneum actually is, which ingredients have RCT support (ceramides, niacinamide, hyaluronic acid, petrolatum), what to skip (exosomes, essential oils, probiotic mists on broken skin), and the four-step protocol that actually rebuilds the lipid matrix. Includes the Sobel Skin Rx barrier routine featuring Bio Hyaluronic Moisture Cream Extreme + 15% Niacinamide Gel Serum.