Across the period from 1961 to 1987, research reframed ovarian aging by showing that postoperative estrogen bioavailability is largely sustained by peripheral aromatization rather than direct ovarian secretion, shifting emphasis toward systemic and peripheral endocrine mechanisms. This shift aligned with a broader agenda to model aging endocrinology using ovarian reserve dynamics, endocrine feedback, and treatment-induced ovarian failure to inform fertility and menopause management. Historical Significance: The era established a cohesive paradigm in which persistent ovarian activity and peripheral hormone synthesis coalesce to shape aging physiology, providing a foundation for later developments in hormone replacement strategies, end-organ regulation, and aging research methodologies.