An 18-year-old woman with PWS, confirmed by genetic testing, was transferred to adult care from the pediatric hospital. She demonstrated multiple clinical features of PWS such as hyperphagia, short stature, learning disabilities, behavioral issues, and episodes of self-mutilation. Past medical history was otherwise only significant for obstructive sleep apnea and obesity (body mass index, 49 kg/m2). She had menarche at the age of 13 years with subsequent secondary amenorrhea (periods of >9 months without menstruating). Her pertinent investigations have been summarized in the. Because of her high estrogen and estrone levels, she was started on cyclic medroxyprogesterone treatment every 3 months, which resulted in normal withdrawal bleeding on this therapy. She also uses topical clindamycin/benzoyl peroxide for acne and had never been treated with growth hormone therapy. She also cited a gradual history of hirsutism over her trunk without virilization.