This document summarizes the female menstrual cycle. It describes that the menstrual cycle occurs over 28 days in the female reproductive system. It involves changes in the ovaries and uterus. In the ovaries, a follicle develops and then ruptures to release an egg (ovulation). If the egg is fertilized, the corpus luteum forms and secretes hormones to support pregnancy. If not fertilized, the corpus luteum breaks down, hormones decrease, and the uterine lining sheds through menstruation. The cycle then begins again with follicle development. Menarche begins the cycles at puberty and menopause ends them in older age.