estrone, a derivative of estradiol and
the second most dominant estrogen; <span style = 'background-color: #dae8f4'>and</span>
estriol, a very short-acting estrogen <span style = 'background-color: #dae8f4'>and</span>
the least biologically active.
The first misconception is that US Food and
Drug Administration (FDA)-regulated drugs are not bioidentical. This is wrong. A long list of FDA-approved hormone products contain 17-beta estradiol and
, therefore, are bioidentical. Examples include oral esterase, estradiol transdermal patches (Climara®, Vivelle®) and
the vaginal ring (Estring®).