Estradiol

Estradiol (E2 or 17β-estradiol, also oestradiol) is a <a href="http://en.wikipedia.org/wiki/Sex_hormone" title="Sex hormone" class="mw-redirect">sex hormone</a>. Estradiol is abbreviated E2 as it has two <a href="http://en.wikipedia.org/wiki/Hydroxyl" title="Hydroxyl">hydroxyl</a> groups in its molecular structure. <a href="http://en.wikipedia.org/wiki/Estrone" title="Estrone">Estrone</a> has one (E1) and <a href="http://en.wikipedia.org/wiki/Estriol" title="Estriol">estriol</a> has three (E3). Estradiol is about 10 times as potent as estrone and about 80 times as potent as estriol in its estrogenic effect. Except during the early follicular phase of the <a href="http://en.wikipedia.org/wiki/Menstrual_cycle" title="Menstrual cycle">menstrual cycle</a>, its serum levels are somewhat higher than that of estrone during the reproductive years of the human female. Thus it is the predominant <a href="http://en.wikipedia.org/wiki/Estrogen" title="Estrogen">estrogen</a> during reproductive years both in terms of absolute serum levels as well as in terms of estrogenic activity. During menopause, estrone is the predominant circulating <a href="http://en.wikipedia.org/wiki/Estrogen" title="Estrogen">estrogen</a> and during pregnancy estriol is the predominant circulating <a href="http://en.wikipedia.org/wiki/Estrogen" title="Estrogen">estrogen</a> in terms of serum levels. Estradiol is also present in males, being produced as an active metabolic product of <a href="http://en.wikipedia.org/wiki/Testosterone" title="Testosterone">testosterone</a>. The serum levels of estradiol in males (14 - 55 pg/mL) are roughly comparable to those of <a href="http://en.wikipedia.org/wiki/Postmenopausal" title="Postmenopausal" class="mw-redirect">postmenopausal</a> women (< 35 pg/mL). Estradiol in vivo is interconvertible with estrone; estradiol to estrone conversion being favored. Estradiol has not only a critical impact on reproductive and sexual functioning, but also affects other organs, including the bones.

Estradiol

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