This case study presents a set of five mini cases that give students an opportunity to explore reproductive hormones and secretions, and to make connections between the endocrine and reproductive systems. Each mini case focuses on an imbalance in reproductive system function and the hypothalamic–pituitary–gonadal (HPG) axis. Working individually or in small groups, students are given a patient description and laboratory test results and tasked with formulating and justifying a diagnosis. Before beginning, students should have already covered both the endocrine and reproductive systems in class so that they can apply their basic understanding of hormones, release sites and targets, and feedback loops to their assigned mini case. This case study was developed for college students in an anatomy and physiology introductory course or an upper-level human physiology course.