Skin aging reflects both intrinsic biological decline and extrinsic influences collectively known as the skin exposome, including ultraviolet (UV) radiation, air pollution, psychosocial stress, fatigue, sleep disruption, and suboptimal lifestyle behaviors. These factors contribute to cumulative molecular and structural damage, positioning the skin as both a visible marker of whole-body aging and a target for longevity strategies. This review examines the validity of an integrative "In and Out" approach, combining topical treatments, such as retinoids, peptides, antioxidants, and exosome-based formulations, with internal nutraceuticals including NAD+ precursors, collagen peptides, polyphenols, and microbiome modulators. By targeting key hallmarks of aging, oxidative stress, inflammation, and epigenetic changes, this dual-modality model has the potential to promote skin regeneration, enhance aesthetic and functional outcomes, and contribute to broader health span optimization. Emerging tools such as skin aging clocks, biomarker-driven personalization, and artificial intelligence (AI)-guided interventions further strengthen this paradigm, establishing a scientifically grounded, preventive, and personalized framework that redefines the role of dermatology in the context of longevity. Personalized strategies that integrate diagnostic tools, lifestyle coaching, and tracking technologies allow for adaptive, dynamic strategies both internally and externally.
Haykal et al. (Thu,) studied this question.