17-estradiol, also referred to as E2, is a form of estrogen that is found in both men and women. In a woman, it helps to maintain healthy reproductive organs. During the menstrual cycle, the hormone is produced in higher levels to prepare the uterine lining for the possible implantation of an embryo. Therefore, the connection between estradiol and menopause is a large drop in the amount of this hormone that is produced by the body. It is not necessary for a woman to produce large amounts of estradiol to sustain a reproductive system that will no longer be in use.
As a woman approaches menopause, her body becomes less sensitive to reproductive hormones. Therefore, the levels of luteinizing hormone and follicle stimulating hormone both increase in order to trigger the same effects on the ovary that occurred earlier in her life. Estrone levels increase as well, but this whole process leads to declining levels of estradiol and menopause. Testosterone levels decrease during this time as well, but the hormone with the most dramatic drop is 17-estradiol. For some women, this period of waning levels of estrogen may begin as much as ten years before their final menstruation.
Due to the severe drop in estradiol levels during menopause, women are at a greater risk for certain types of cancer. Estrogen plays a role in calcium absorption, so loss of these hormones also weakens the bones and teeth. Women might notice a link between lower levels of estradiol and menopause when their moods begin to shift, as drops in estrogen have been connected to lowered moods.
As a way to mitigate the problems associated with estradiol and menopause, some women undergo hormone replacement therapy (HRT). These women either take estrogen alone or as a combination of estrogen and progesterone. Delivery of the hormone can be through a variety of methods including creams, pills, patches, vaginal rings, and vaginal suppositories. HRT helps women to shed their uterine lining, reducing the build-up of cells which can lead to uterine cancer.
While short-term therapy giving low doses of estrogen has been found to be effective in reducing cancer rates, improving bone health as well as women’s moods during menopause, there are risks associated with HRT. Women who only take estrogen and still have their uterus may actually be at greater risk for endometrial cancer. Some studies have found connections between HRT and higher rates of strokes and heart disease. Still, women facing side effects from lower levels of estradiol and menopause might want to discuss HRT with their gynecologists to see if it would help.