Due to the differences in the development of each woman’s follicles and their sensitivity to different ovulation-promoting drugs, the fastest days to ovulate after taking ovulation-promoting drugs vary. In general, ovulation medication is started after the 5th day of menstruation for five days, and then follicle monitoring under ultrasound is started after five days interval. When the follicles develop to about 2cm in diameter, ovulation may occur at any time. If a patient’s follicles are mature, most patients may ovulate within 12-36 hours after the medication is administered to promote follicular rupture alone. In addition, ovulation-promoting medications are prescribed and may cause ovarian hyperstimulation syndrome if not applied properly.