Participants will be admitted to the NIH Clinical Center inpatient service or the outpatient day hospital twice for pharmacokinetic studies (blood drawing to measure blood levels of CDB-2914 after a single dose of the drug). They will come to the Clinical Center at 7:00 a.m. and have a catheter (thin plastic tube) inserted into an arm vein for drawing blood for the first 24 hours of the study. Eight milliliters (about 2 teaspoons) of blood will be drawn 5 minutes and 1 minute before taking CDB-2914 (in either crystalline or micronized powder form) and then at the following times after taking the drug: 15, 30, 45, 60, 75, 90, 105, 120, 150 and 180 minutes (3 hours), and 4, 6, 8, 10, 12, 24, 48, 72, 96, 120 hours (5 days).