What role does Cortisol play in skin aging?

Cortisol, the primary stress hormone, influences skin aging through several well-described mechanisms. Chronically elevated cortisol can degrade collagen and elastin by inhibiting fibroblast activity and increasing matrix metalloproteinases (MMPs), leading to loss of firmness and wrinkle formation. It also impairs the skin barrier, reduces hydration, and promotes inflammation, which accelerates photoaging and can worsen conditions like acne or eczema. Additionally, cortisol may disrupt the skin's microbiome and slow wound healing. However, direct human evidence linking cortisol levels to visible skin aging is limited; most data come from in vitro studies or indirect observations (e.g., in Cushing's syndrome). While stress management is often recommended for skin health, the causal role of cortisol in routine skin aging remains an area of active research. The provided context does not contain specific information on cortisol and skin aging, so this answer is based on general scientific knowledge. Therefore, the evidence level is considered 'mechanistic' rather than strong human evidence.