Figure 1.

Study protocol diagram. Following medroxyprogesterone withdrawal menstruation, in eight treatment cycles, women received neurokinin 3 receptor antagonist (NK3Ra; MLE4901) 40 mg oral twice daily starting from Cycle day 1–2 for 7 days, and in 7 cycles, women received no treatment. On Day 6 or 7 of NK3Ra dosing in the treatment group and the equivalent day in the no treatment group, women were randomized to 7 h kisspeptin-10 or vehicle infusion, returning for alternate infusion after subsequent medroxyprogesterone induced menstruation. Reproductive hormones were measured throughout the study and LH pulsatility was assessed during 10-min frequent blood sampling for 8 h on the infusion day.