Estradiol is a very important hormone in both men and women. It belongs to a group of hormones called estrogens, which are steroid hormones made mostly in the ovaries in women and in smaller amounts in adipose tissue and testes in men.
Functions of Estradiol
Some major functions of estradiol include:
- Plays a vital role in the menstrual cycle and reproductive health in women
- Helps thicken the endometrium (uterine lining) to prepare for pregnancy
- Aids in maintaining bone density and strength
- Regulates cholesterol levels
- Influences hair growth and skin health
- Plays a role in vasodilation (widening of blood vessels)
- Contributes to salt and water balance in the kidney
Role in Women
In women, estradiol levels fluctuate through the menstrual cycle under the control of follicle-stimulating hormone (FSH) and luteinizing hormone (LH).
- Estradiol peaks just before ovulation to trigger the release of an egg from the ovaries
- After ovulation, estradiol levels decrease, and progesterone levels rise to maintain a pregnancy if fertilization occurs
- Falling estradiol levels trigger menstruation if no pregnancy occurs
Therefore, estradiol is truly the "
queen of hormones" for the female reproductive system. Declining estradiol during perimenopause and menopause causes changes like hot flashes, vaginal dryness, and mood changes.
Role in Men
In men, estradiol is essential for modulating libido, erectile function, and spermatogenesis. As men age, estradiol levels gradually decline. Extremely low levels can lead to adverse effects on bone, cardiovascular, sexual, and cognitive health.
While estradiol levels are much lower in men compared to premenopausal women, estradiol still plays a vital regulatory role. Both men and women need balanced levels of this key hormone for optimal health.