Dr. Peffley received his doctorate in Genetics from the Pennsylvania State University and did his postgraduate training in molecular biology at The University of Colorado School of Medicine. His initial faculty appointment was in the Department of Pharmacology at the University of Tennessee Health Sciences Center where he received grants from the American Heart Association and the National Heart Lung and Blood Institute to establish a research program in the regulation of cholesterol synthesis. He later moved to the Rosalind Franklin School of Medicine in North Chicago, Illinois where he was promoted to the rank of Associate Professor. Dr. Peffley also served on the faculty of the Kansas City University of Medicine and Biosciences as Professor of Biochemistry.
He moved to the University of South Carolina School of Medicine-Greenville from the Edward Via College of Osteopathic Medicine in Spartanburg, SC where he held an appointment as Chair and Professor of Biochemistry. Dr. Peffley also holds a Juris Doctor degree from the University of Missouri Kansas City School of Law and was admitted to the Missouri Bar and the District of Columbia Bar. His research interests focus on the nutritional prevention of cancer and he has held multiple grants from the National Cancer Institute to support this research.