Mean (± SE) baseline and peak serum E2 levels after administration of rFSH in Ovulatory Control (OC, n=22) and Polycystic Ovary Syndrome (PCOS, n=8) participants at doses of low (0.5 IU/kg/d), medium (1.1 IU/kg/d), and high (2.2 IU/kg/d). Significant change from baseline to peak is denoted by asterisks. *, P<0.05; **, P<0.01; ***, P<0.001.