estriol

noun

es·​tri·​ol ˈe-ˌstrī-ˌȯl How to pronounce estriol (audio)
e-ˈstrī-, 
-ˌōl How to pronounce estriol (audio)
: a relatively weak natural estrogenic hormone that is a glycol C18H24O3 found in the body chiefly as a metabolite of estradiol, is the main estrogen secreted by the placenta during pregnancy, and is the estrogen typically found in the urine of pregnant women

Examples of estriol in a Sentence

Recent Examples on the Web
Examples are automatically compiled from online sources to show current usage. Read More Opinions expressed in the examples do not represent those of Merriam-Webster or its editors. Send us feedback.
Powered by bioidentical estriol and peptides, the treatment is designed to help rebuild collagen, restore elasticity and improve skin density over time. — Kathryn Hopkins, Footwear News, 12 May 2026 Launching Tuesday and following on the heels of M4 Face Cream Rx, M4 Body Treatment Rx is a prescription estriol body treatment designed specifically for menopausal skin. — Kathryn Hopkins, Footwear News, 12 May 2026 Monica Molenaar, Alloy’s co-founder, first discovered estriol while living in the Netherlands. — Micaela English, Flow Space, 27 Aug. 2025 Living in the Netherlands, Molenaar was able to quickly get a vaginal estrogen prescription in the form of estriol quickly and within two weeks her symptoms were completely gone. — Emily Burns, Footwear News, 3 Sep. 2019 Both products feature the hero ingredient estriol, a form of estrogen, as well as a peptide to enhance the firming and smoothing effects. — Emily Burns, Footwear News, 3 Sep. 2019

Word History

Etymology

estrane + tri- + -ol entry 1

First Known Use

1933, in the meaning defined above

Time Traveler
The first known use of estriol was in 1933

Rhymes for estriol

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Browse Nearby Words

estrich
estriol
estrogen
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Cite this Entry

“Estriol.” Merriam-Webster.com Dictionary, Merriam-Webster, https://www.merriam-webster.com/dictionary/estriol. Accessed 3 Aug. 2026.

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Medical Definition

estriol

noun
es·​tri·​ol ˈes-ˌtrī-ˌȯl How to pronounce estriol (audio) e-ˈstrī- How to pronounce estriol (audio)
-ˌōl
variants or chiefly British oestriol
ˈē-ˌstrī-ˌȯl How to pronounce estriol (audio) ē-ˈstrī- How to pronounce estriol (audio)
-ˌōl
: a relatively weak natural estrogenic hormone that is a glycol C18H24O3 found in the body chiefly as a metabolite of estradiol, is the main estrogen secreted by the placenta during pregnancy, and is the estrogen typically found in the urine of pregnant women

More from Merriam-Webster on estriol

Britannica.com: Encyclopedia article about estriol

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