Mechanism and Applications of Raman Spectroscopy in Cosmetics

ABSTRACT Raman spectroscopy, a technique rooted in the inelastic scattering of photons, has emerged as an influential tool in various scientific domains, including biology, materials, and cosmetics science. Raman spectroscopy enables real‐time, in situ, noninvasive analysis of cosmetic ingredients on the skin surface and internally. The employment of the aforementioned method in conjunction with the deep penetration capability of confocal Raman microscopy (CRM) enables layer‐by‐layer tracking of penetration behavior from the stratum corneum (SC) to the dermis. It utilizes molecular vibrational fingerprint analysis to achieve cross‐scale (cell to tissue) in vivo evidence for investigating cosmetic efficacy mechanisms. This review focuses on mechanisms and applications of Raman spectroscopy in cosmetics, emphasizing its unique advantages in skin analysis, efficacy evaluation, and quality control. Combining multivariate analysis with Raman spectroscopy data processing enhances its reliability in product evaluation. Overall, Raman spectroscopy holds great promise for furthering understanding of cosmetic science and improving product development and efficacy evaluation.