The generic name of Dayeng is Ethinyl Estradiol Cyproterone Tablets. You can take ethinyl estradiol cyproterone tablets during menstruation. Ethinyl estradiol cyproterone tablets contain 2 mg of cyproterone acetate and 35 μg of ethinyl estradiol per tablet. Cyproterone acetate also has a significant progesterone-like effect, when used alone can lead to menstrual cycle disorders, in this drug and ethinyl estradiol combined, can inhibit ovarian ovulation, to achieve contraceptive effect. Patients taking ethinyl estradiol cyproterone tablets usually start on the first day of menstruation, such as starting on the second to fifth day of the menstrual cycle, the first 7 days need to be added to the barrier contraceptive method. Ethinyl estradiol cyproterone tablets are prescription drugs, patients need to follow the doctor’s instructions for medication.