Menstrual cycle between 45 and 55 years of age. Bleeding usually lasts around 2 to 7 days. The menstrual cycle is governed by hormonal changes. These changes can be altered by using hormonal birth control to prevent pregnancy. Each cycle can be divided into three phases based on events in the ovary (ovarian cycle) or in the uterus (uterine cycle). The ovarian cycle consists of the follicular phase, ovulation, and luteal phase whereas the uterine cycle is divided into menstruation, proliferative phase, and secretory phase. Stimulated by gradually increasing amounts of estrogen in the follicular phase, discharges of blood (menses) flow stop,
Menstrual cycle not found with women on the birth control pill. Women's preference for male's body odor can change across the menstrual cycle. Males who score highly on dominance have been rated as sexier by females during the fertile phase of the menstrual cycle. Additionally, during their most fertile phase of the menstrual cycle, women may show preference for the odor of symmetrical men. This effect is not found for women on the birth control pill. Also, during the late follicular and ovulatory phases, women prefer the scent of masculine men. The scent of androsterone (responsible for testosterone levels) is highly preferred