Many doctors want to know more about the FDA not only so that they might better understand the issues and how they are related to their practice, such as off label-drug usage, but also to enrich their professional lives and allow them to more deeply understand the many FDA related articles written in the popular press. It is further based on the notion that doctors prefer a formal way to learn about FDA. The Agency is a truly vast subject engaging thousands of lawyers, regulators, scientists, physicians, writers, legislators and many others directly and indirectly. This book is an introductory overview written from a physician perspective for physicians. It is organized along lines that emphasize issues most interesting to physicians. Much of it deals with nomenclature and definitions, since as is true of all fields, one must understand the special concepts and vocabulary of the field.