What is Estrogen?
Estrogen is not one hormone, it is the name of a
group of hormones. There are three principle forms of estrogen found in
the human body estrone, estradiol and estriol, also known as E1, E2 and E3
There is also a group of compounds called phytoestrogens, which are not
hormones but occupy estrogen receptors in the body and offer protection
against xeno-estrogens in the body.
Estradiol (E2) is the primary estrogen produced by the ovaries. Estrone
(E1) is formed from estradiol. It is a weak estrogen and is the most
abundant estrogen found in the body after menopause. Estriol (E3) is
produced in large amounts during pregnancy and is a breakdown product
of estradiol. Estriol is also a weak estrogen and may have anti-cancer
effects and is the primary form of estrogen used to treat hot flashes,
night sweats and vaginal dryness.
Before menopause estradiol is the predominant estrogen. After menopause
estradiol levels drop more than estrone so that now estrone is the
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