estriol

biochemistry

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June 26, 2026

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Estriol is a weak, naturally occurring estrogenic hormone that is a metabolite of estradiol. It is primarily produced by the placenta during pregnancy and is the main estrogen found in the urine of pregnant women. Estrogens, including estriol, estradiol, and estrone, are hormones that influence the development and function of the female reproductive tract. They are synthesized from cholesterol in the ovaries and placenta. While estradiol is the most potent estrogen, estriol is the weakest.1234

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estriol
estrogen
steroid hormone
estradiol

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hormone
Estrogens
…and other mammals, estrone and estriol, are much less active than estradiol, estriol being the weakest. Estrone can be converted to estradiol and vice versa in the ovary and in other tissues; e.g., estradiol is converted, particularly in the liver, to estriol, which is an excretory product. The metabolism of…
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…and other mammals, estrone and estriol, are much less active than estradiol, estriol being the weakest. Estrone can be converted to estradiol and vice versa in the ovary and in other tissues; e.g., estradiol is converted, particularly in the liver, to estriol, which is an excretory product. The metabolism of…
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estrogen
Synthesis and secretion of estrogen
Estriol, the weakest of the estrogens, is formed from both estrone and estradiol.
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Estriol, the weakest of the estrogens, is formed from both estrone and estradiol.
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