We will be administering combinations of three drugs: Testosterone (T) by gel, Depot Medroxyprogesterone acetate (DMPA) and Acyline to see their effects on sperm production. The T/DMPA/Acyline combination will allow us to determine if the more rapid and complete gonadotropin suppression mediated by the early addition of a GnRH antagonist will accelerate and enhance suppression of spermatogenesis.