What role does TSH play in skin aging?

TSH (thyroid-stimulating hormone) regulates thyroid hormone production. Thyroid hormones influence skin metabolism, collagen synthesis, and cell turnover. Hypothyroidism (elevated TSH) can cause dry, coarse skin and delayed wound healing, while hyperthyroidism (low TSH) is associated with thin, moist skin. Both conditions may accelerate skin aging. However, direct evidence for TSH as an independent biomarker of skin aging is weak; effects are primarily mediated via thyroid hormones. A normal TSH level is important for skin health, but a TSH test alone without additional thyroid parameters (fT3, fT4) is insufficient for assessing skin aging. Evidence is based on mechanistic links and observational studies, not randomized controlled trials. Caution: Single TSH measurements can fluctuate; for skin concerns, a physician should evaluate full thyroid function.