A synthetic progestogen; prevents fertilization and increases the rate of transport of eggs from the fallopian tubes to the uterus in female ferrets when administered prior to ovulation; reversibly blocks ovulation in rats when injected on the last day of diestrus; has anti-androgenic activity in rats, decreasing plasma testosterone levels via induction of hepatic testosterone reductase activity; inhibits production of IFN-γ by CD2/CD3/CD28-stimulated PBMCs and extends the survival of rabbit skin allografts