Feb 24, 2026Skin Aging and Photoaging: Mechanisms, UV Damage, and Evidence-Based InterventionsSkin aging involves intrinsic (chronological) and extrinsic (UV-driven photoaging) components. UV radiation is responsible for approximately 80% of visible facial aging. Topical retinoids have the strongest evidence base for reversing photoaging signs. Oral collagen peptides have emerging RCT evidence for skin hydration and elasticity. Sun protection remains the highest-impact preventive intervention.