Dr Fein earned his medical degree from Columbia University College of Physicians and Surgeons. He was a house officer in medicine at Bellevue Hospital and completed his post-graduate medical education in endocrinology at the National Institutes of Health. Dr Fein has more than 25 years of experience treating patients as a staff physician at Walter Reed Army Medical Center in Washington, D.C., while serving as an associate professor of medicine at the Uniformed Services University of the Health Sciences F Edward Hebert School of Medicine in Bethesda. He has conducted extensive research and written numerous articles on subjects relating to drug research and pituitary/hypothalamic neuroendocrinology.