Is high dosage testosterone an effective male contraceptive agent?*†*Presented in part at the Western Section of the American Federation for Clinical Research Meeting, Carmel, California, February 16 to 19, 1988.†Supported by the Environmental Protection Agency grant DW36931233-01-0, World Health Organization (project no. 86064), National Institutes of Health Grant P50-HD-12629, University of Washington Clinical Research Center (National Institutes of Health grant RR-37), and Veterans Administration Medical Research Funds.