Abstract Skin moisturizing is important in dermatology and cosmetics. Raman microspectroscopy a well‐suited method to determine water concentration profiles the stratum corneum (SC) of untreated formulation‐treated skin vivo. Until now, SC was quantified using ratio proteins, other components were neglected. Here, we apply tailored multivariate curve resolution‐alternating least squares (tMCR‐A...