A synthetic GNRH agonist; binds to the GNRHR (Ki = 1.6 nM in CHO cells expressing the human receptor); binds to mouse pituitary αT3-1 cells and human placenta (Kds = 2 and 580 nM, respectively) and increases intracellular calcium in αT3-1 cells; induces testosterone production in vitro within 4 h in rat Leydig cells (ED50 = 83 nM) but decreases testosterone plasma level in vivo in rats over a period of 2 to 24 weeks; inhibits tumor growth in a DU145 human prostate carcinoma mouse xenograft model (100 μg per day)