Frances Hayes, M.D., is an Associate Professor of Medicine at Harvard Medical School, Interim Chief of Endocrinology at Massachusetts General Hospital and a Fellow of the Royal College of Physicians of Ireland. Her prior research focused on male hypogonadism, a topic on which she has lectured and published widely including being a co-author on the Endocrine Society Clinical Practice Guidelines on testosterone therapy. Her clinical practice includes men and women with the full spectrum of reproductive disorders including PCOS and menopause. She is the Endocrine Director of multi-disciplinary clinics dedicated to the care of patients with Turner syndrome, Klinefelter syndrome and Gender Dysphoria.