“…Another critical role of estrogen in COCs is providing cycle control and reducing spotting, which is a hormonal breakthrough bleeding. Studies show that spotting and intermittent bleeding are less with shorter HFI formulations when compared to the formulations with the same EE dose but a longer HFI [16]. In a meta-analysis of low-dose estrogencontaining tablets, there was less intermittent bleeding with tablets with a short hormone-free interval [17].…”