Estradiol is one of the most important estrogens in the human body. It is a steroid hormone that is essential for sexual and reproductive development, mainly in women. Estradiol has several key functions:
- Regulates the menstrual cycle - Estradiol controls the growth of the uterine lining during the first part of the menstrual cycle. It causes the lining to thicken to prepare for a potential pregnancy. If pregnancy does not occur, estradiol levels fall, leading to menstruation.
- Stimulates breast development - Estradiol promotes the growth of ducts and stromal tissues in the breasts during puberty. It is responsible for the development of female secondary sex characteristics.
- Affects bone density - Estradiol has a protective effect on bone. It helps regulate bone turnover and can prevent bone loss and osteoporosis in women after menopause.
- Influences skin and hair - Estradiol may contribute to skin thickness, moisture and collagen content. It also plays a role in hair growth patterns.
- Regulates cholesterol - Estradiol helps reduce low-density lipoprotein (LDL) cholesterol while increasing high-density lipoprotein (HDL) cholesterol. This offers protection against heart disease.
Where does estradiol come from?
In women, estradiol is mainly produced by the ovaries. It is synthesized from cholesterol through a series of chemical reactions. The ovaries release estradiol into the bloodstream, where it travels to different tissues and exerts its effects.
Smaller amounts of estradiol are also produced in other tissues like the liver, adrenal glands, breasts and fat cells. During menopause, ovarian estradiol production drops significantly as women run out of ovarian follicles. However, estradiol continues to be locally produced in tissues.
Estradiol levels fluctuate throughout a woman's life. Levels are lowest prior to puberty, peak during the reproductive years, then fall during perimenopause and menopause. Estradiol levels also vary throughout the menstrual cycle, with the highest secretion occurring just before ovulation.
When are estradiol levels tested?
Some common reasons estradiol may be tested include:
- Evaluating menopausal symptoms like hot flashes and vaginal dryness
- Detecting early or delayed puberty
- Diagnosing causes of absent or irregular periods
- Monitoring fertility treatment like IVF
- Assessing hormone balance in transgender women
- Tracking the source of estrogen-sensitive cancers like breast cancer
At The Hormone Hub, we use cutting-edge estradiol testing to provide personalized care for women throughout all stages of life. Our compassionate providers partner with you to optimize hormone health, relieve menopausal symptoms, improve fertility and help you feel your best. Contact us today to learn more about estradiol testing and balanced hormone care.