Britannica Sources used in this answer

How do estrogen and progesterone affect the menstrual cycle?

Created from Britannica articles using AI. AI can make mistakes, so verify using Britannica articles.

human endocrine system The principal glands of the female and male human endocrine systems.

Estrogen and progesterone are essential hormones produced by the ovaries that regulate the menstrual cycle through a complex feedback loop.1

During the follicular phase, maturing follicles secrete increasing amounts of estradiol, which stimulates the proliferation of the uterine lining (endometrium). This rising estrogen, alongside a small amount of progesterone, triggers a surge in luteinizing hormone (LH), leading to ovulation.12

Following ovulation, the luteal phase begins as the corpus luteum produces large quantities of progesterone and some estrogen. Progesterone prepares the endometrium to receive a fertilized egg and inhibits uterine contractions. If fertilization does not occur, the corpus luteum degenerates, causing a sharp decline in both hormones. This withdrawal constricts uterine arteries, leading to the shedding of the endometrial lining, which manifests as menstruation. Additionally, progesterone is responsible for the post-ovulatory increase in basal body temperature.12