Hormones
Estradiol (E2)
Estrogen, E2
Included in Baseline and Complete.
Compare membershipsBoth women and men rely on estradiol.
Estradiol is the main form of estrogen during the reproductive years. It guides the menstrual cycle and helps keep bones strong, and men make it too, mostly from testosterone.
Your result depends on when it's drawn.
Before menopause, estradiol rises and falls across the menstrual cycle, so the same person can have very different results on different days. Knowing the first day of your last period helps your clinician read the number. Levels become less predictable in the years before menopause and stay low afterward.
In men, much of the estradiol is made from testosterone, partly in body fat, so it's usually read alongside testosterone. Standard tests are less precise at the low levels seen in men and after menopause. Birth control pills, hormone therapy, and biotin supplements can also affect results.
Estradiol is a moving target, so timing is part of the result.
Questions
Why would a man have his estradiol checked?
Men need some estrogen, which their bodies make mainly from testosterone. Too little is associated with bone loss and lower sex drive, and too much is associated with breast tissue growth, erectile problems, or fertility issues. Estradiol is best read alongside testosterone and SHBG.
Can an estradiol test show whether I'm in perimenopause?
Not on its own. Estradiol can swing widely during the years around menopause, so a single result may look high, low, or typical. Your symptoms, cycle pattern, age, and other hormone results give a clearer picture, and you may need more than one test.