Hormones exert a powerful and long-lasting influence on tissue biology by shaping how genes are expressed over time. This regulatory dimension, referred to as the endocrine epigenome, provides a unifying perspective to understand how identical genomes can give rise to profoundly different phenotypes, rates of aging, and adaptive capacities. Skin, as a hormonally sensitive, regenerative, and environmentally exposed organ, offers a particularly relevant model to explore these dynamics in a context of high interest for cosmetic science.
Across the lifespan, hormonal signals act in concert with metabolic and environmental factors to influence skin structure, resilience, and the capacity to maintain its physiological functions. Circadian hormones such as melatonin, cortisol as a key mediator of metabolism and stress, and (female) sexual hormones play central roles in orchestrating repair processes, inflammatory balance, extracellular matrix homeostasis, and barrier integrity. Importantly, skin biology appears to be influenced not only by hormone levels, but also by the temporal organization and coherence of endocrine signals. Rhythmic hormonal patterns tend to support balanced adaptation and repair, whereas dysregulated or noisy endocrine states are associated with increased vulnerability, altered aging trajectories, and reduced resilience. Such contrasts become particularly evident during phases of hormonal variability, including the menstrual cycle and the transition through perimenopause and menopause.
By linking hormonal contexts to molecular and cellular responses in skin, this presentation proposes a systems-level view of hormone–skin interactions that goes beyond single targets or ingredients. Highlighting representative pathways and biomarkers relevant to skin quality and aging, it aims to provide cosmetic scientists, evaluators, and developers with conceptual tools to rethink active design, testing strategies, and interpretation of efficacy through the lens of endocrine-driven regulation.