A RECENT RELEASE (Aug 4, 1963) to the lay press by the Food and Drug Administration contained conclusions based on the report by an advisory committee of medical experts of the oral contraceptive Enovid (a mixture of norethynodrel and mestranol). A committee of nine experts, with Dr. Irving S. Wright as chairman, was charged with the responsibility of studying the available data to determine the possible relationship between the use of Enovid and the incidence of thromboembolic disease, including thrombophlebitis and pulmonary embolism, and the mortality from these conditions in the US. The Committee began with an examination of more than 350 case reports of thromboembolic disease from the files of the FDA and the manufacturer. Since preliminary investigation indicated that it was impossible to obtain solid comparable statistics concerning these complications, they decided to concentrate on the deaths since the documentation here would be more complete and valid. Mindful of the importance of changes in the coagulation balance, the Committee reviewed the pertinent literature and carried out special studies in the laboratories of members of the Committee in an attempt to answer some of the questions relating to this subject. On the basis of the findings during