What role does Testosteron play in skin aging?

The provided context does not contain specific information on testosterone's role in skin aging. Generally, testosterone influences collagen synthesis, sebum production, and hair follicle cycling, which may affect skin thickness and aging. However, evidence is mixed: age-related testosterone decline in men is linked to reduced skin density, while in women the effects are less clear due to estrogen dominance. The context snippets (DNA tests, cortisol, gut-brain axis) are not directly relevant. Therefore, the evidence grade is unclear. Caveat: skin aging is multifactorial (UV, lifestyle, genetics); hormone testing alone should not replace clinical dermatological assessment.