Estrogen is an important hormone for women. It is responsible for the development of female secondary sex characteristics during puberty and helps regulate the menstrual cycle. After menopause, when the ovaries stop producing eggs, estrogen levels decline dramatically. This leads many to wonder – where does estrogen come from after menopause if it is no longer being produced by the ovaries?
What is estrogen?
Estrogen refers to a group of hormones that play an essential role in female reproduction and sexual development. The three major estrogens in women are:
- Estradiol – the primary estrogen during a woman’s reproductive years. Estradiol is produced mainly by the ovaries.
- Estrone – less potent than estradiol and produced by the ovaries, adrenal glands, and fat tissue.
- Estriol – the weakest of the three estrogens and produced during pregnancy by the placenta.
These hormones work together to stimulate the development of female secondary sex characteristics like breast growth, regulate the menstrual cycle, and maintain the health of tissues like the vagina, uterus, and bones.
Estrogen levels during menopause
Menopause marks the end of a woman’s menstrual cycles and fertility. It usually occurs naturally between the ages of 45-55. During the menopausal transition, estrogen levels gradually decline as ovarian function diminishes.
Postmenopause is marked by 12 consecutive months without a period. At this point, ovary estrogen production has dropped by about 95% compared to premenopausal levels. However, the body continues producing estrogen from other sources.
Effects of declining estrogen
The sharp drop in estrogen during menopause can lead to many symptoms, including:
- Hot flashes and night sweats
- Vaginal dryness and discomfort
- Mood changes like depression
- Sleep problems
- Bone loss
Lower estrogen after menopause also increases women’s risk for certain health conditions like osteoporosis and heart disease.
Where does estrogen come from after menopause?
Although the ovaries stop making estrogen after menopause, low levels of estrogen continue to be produced in the body through a few different pathways:
Conversion of androgens
After menopause, the primary source of estrogen becomes the conversion of androgens like testosterone and androstenedione. These hormones are produced by the adrenal glands and ovaries.
Aromatase is the enzyme responsible for the conversion of androgens into estrogens. Fat tissue contains high levels of aromatase, so more estrogen is produced in women with higher percentages of body fat.
Ovarian production
The postmenopausal ovary continues to produce low, residual levels of estrogen. Approximately 10% of a woman’s estrogen after menopause comes from the ovaries.
Adrenal glands
The adrenal glands produce the androgens DHEA and DHEA-S, which can then be converted into estrogen in fat tissue. The adrenal glands are estimated to supply about 20% of all estrogen after menopause.
Peripheral tissues
Local estrogen is also produced by aromatase activity in body tissues like fat, muscle, skin, bone, and the brain. This accounts for a smaller percentage of total estrogen after menopause.
Role of estrogen after menopause
The low levels of estrogen produced after menopause still help protect bone health, heart health, brain function, and other tissues that are sensitive to estrogen levels.
Bone health
Estrogen helps maintain bone density by inhibiting bone breakdown. After menopause, reduced estrogen contributes to accelerated bone loss. This puts women at higher risk for osteoporosis and fractures.
Heart health
Estrogen is thought to have a protective effect on cardiovascular health in women before menopause. Postmenopausal estrogen production may still confer some cardiovascular benefits by maintaining good cholesterol levels.
Brain health
Estrogen receptors are present in brain regions like the hippocampus and frontal cortex. Estrogen may help protect memory and cognitive function during and after menopause.
Other effects
Locally produced estrogen helps maintain the elasticity and lubrication of tissues like vaginal epithelium and skin. Estrogen also plays a part in regulating body temperature after menopause.
Conclusion
In summary, here are the key takeaways about where estrogen comes from after menopause:
- The ovaries stop producing estrogen after menopause, leading to a significant decline in levels.
- Low levels of estrogen continue to be produced in the body from the conversion of adrenal and ovarian androgens.
- Fat tissue and the adrenal glands are the primary sources of estrogen after menopause.
- Postmenopausal estrogen production is still important for protecting bone, heart, brain, and tissue health.
Understanding how the body continues making estrogen is important for women’s health during the postmenopausal period. Maintaining adequate estrogen levels can help prevent conditions like osteoporosis that are associated with menopause-related estrogen deficiency. If estrogen levels become too low, hormone therapy may be an option for relieving menopausal symptoms and preventing long-term health risks.