Changes in Hormone Levels
Many changes during the years leading up to menopause (perimenopause) are brought on by changing levels of hormones produced by the ovaries, mainly estrogen.
Estrogen. As the primary “female” hormone, estrogen promotes the growth and health of the female reproductive organs and keeps the vagina moisturized, elastic (stretchy), and well supplied with blood. Estrogen levels generally decline during perimenopause, but they do so in an irregular fashion. Sometimes there can be more estrogen present during perimenopause than in the past.
Estrogen levels generally decline during perimenopause, but they do so in an irregular fashion.
As detailed in the table below, the reduced production of estrogen beginning in perimenopause can affect your sexual function directly, such as through vaginal dryness. It can also do so indirectly, in the form of hot flashes and night sweats, which can drain your energy and undermine your desire for sex as a result. These effects are discussed in detail in the “Causes of Sexual Problems” section of this program.
Progesterone and testosterone. In addition to estrogen, levels of other hormones produced by the ovaries—progesterone (another female hormone) and testosterone (a male androgen hormone produced at lower levels in women)—are also changing during your midlife years, as explained in the table below.
Intermittent decreases in progesterone affect menstrual periods more than they affect sexual function, but age-related declines in testosterone may dampen libido (sex drive) in midlife women, although this remains controversial. The fact that estrogen declines more than testosterone leads some to believe that libido should not decline at menopause. The decline in testosterone in women is solely age-related, not menopause-related, and begins years before perimenopause.
|The rise and fall of women's sex hormones
|What does this hormone do?
- Stimulates growth of breast tissue
- Maintains vaginal blood flow and lubrication
- Causes lining of the uterus to thicken during the menstrual cycle
- Keeps vaginal lining elastic
- Many other functions, including preserving bone
|Prepares lining of the uterus for a fertilized egg and helps maintain early pregnancy
Although known as the “male” hormone, testosterone is also important to women’s sexual health:
- Plays a key role in women’s estrogen production
- Contributes to libido
- May help maintain bone and muscle mass
|How do menopause
and age affect this hormone?
|During perimenopause, levels fluctuate and become unpredictable. Eventually, production falls to a very low level.
||Production stops during menstrual cycles when there is no ovulation and after final menstrual period
- Levels peak in a woman’s 20s and decline slowly thereafter. By menopause, level is at half of its peak.
- Ovaries continue to make testosterone even after estrogen production stops
- Testosterone production from adrenal glands also declines with aging
but continues after menopause
|What symptoms may result
- High levels can result in bloating, breast tenderness, heavy bleeding
- Low levels can result in hot flashes, night sweats, palpitations, headaches, insomnia, fatigue, bone loss, vaginal dryness
|Lack of progesterone can cause periods to become irregular, heavier, and longer during perimenopause
||Effects of testosterone decline are uncertain
Adapted, with permission, from Shifren JL, Hanfling S. Sexuality in Midlife and Beyond: Special Health Report. Harvard Health Publications, Boston, MA. Copyright © 2010 Harvard University.