Despite the substantial efficacy of COCs in preventing pregnancy, it is widely recognized that traditional COCs do not provide complete ovarian suppression [6], [19] and [20]. Several studies have demonstrated that adding low-dose (10 mcg) EE during the traditional HFI suppresses pituitary–ovarian activity and ovarian follicular development [9], [10] and [21]. While this study did not evaluate ovarian suppression, results indicate that the 21/7-active DSG/EE COC regimen effectively prevents pregnancy.