Jeremy A. Greene is associate professor of medicine and the history of medicine and the Elizabeth Treide and A. McGehee Harvey Chair in the History of Medicine at the Johns Hopkins University School of Medicine. He is the author of Prescribing by Numbers: Drugs and the Definition of Disease and Generic: The Unbranding of Modern Medicine, both published by Johns Hopkins. Elizabeth Siegel Watkins is a professor, vice chair, and director of graduate studies in the History of Health Sciences Program at the University of California, San Francisco. She is the author of The Estrogen Elixir: A History of Hormone Replacement Therapy in America and On the Pill: A Social History of Oral Contraceptives, 1950-1970, both also published by Johns Hopkins, and the coeditor of Medicating Modern America: Prescription Drugs in History.