Estradiol for tissue of the reproductive organs, supporting the lining of the vagina, the cervical glands, the endometrium, and the lining of the fallopian tubes. It enhances growth of the myometrium. Estradiol appears necessary to maintain oocytes in the ovary. During the menstrual cycle, estradiol produced by the growing follicles triggers, via a positive feedback system, the hypothalamic-pituitary events that lead to the luteinizing hormone surge, inducing ovulation. In the luteal phase, estradiol, in conjunction with progesterone, prepares the endometrium for implantation. During pregnancy, estradiol increases due to placental production. The effect of estradiol, together with estrone and estriol, in pregnancy
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