Menstrual bleeding is triggered by a drop in the levels of both estrogen and progesterone.
The Role of Estrogen and Progesterone
According to provided information, estrogen and progesterone are crucial hormones in the menstrual cycle. They are produced in the ovaries. These hormones build up the lining of the uterus (endometrium) in preparation for a possible pregnancy.
What Happens During Menstruation?
When pregnancy doesn't occur, the levels of estrogen and progesterone decline. This decline causes the thickened uterine lining to shed, resulting in menstrual bleeding. Therefore, it's not a single hormone, but the decrease in both estrogen and progesterone that leads to menstruation.
