estrogen

noun

es·​tro·​gen ˈe-strə-jən 

: any of various natural steroids (such as estradiol) that are formed from androgen precursors, that are secreted chiefly by the ovaries, placenta, adipose tissue, and testes, and that stimulate the development of female secondary sex characteristics and promote the growth and maintenance of the female reproductive system

also : any of various synthetic or semisynthetic steroids (such as ethinyl estradiol) that mimic the physiological effect of natural estrogens

Examples of estrogen in a Sentence

Recent Examples on the Web

During menopause, your estrogen levels drop significantly. —Wendy Wisner, Health, 20 June 2025

One drug, an aromatase inhibitor, reduces the amount of estrogen in the body. —The New York Times News Service Syndicate, San Diego Union-Tribune, 10 June 2025

Due to a combination of biological advantages—such as protective effects of estrogen and stronger immune responses—and behavioral factors like lower rates of risky activities, better health-seeking habits, and less exposure to occupational hazards and violence, women live longer than men. —Geri Stengel, Forbes.com, 5 June 2025

And for another, the symptoms creatine may address—from brain fog to poor sleep—are super common among women, including in midlife, thanks to fluctuating levels of hormones like estrogen from month to month and especially entering the transition into menopause. —Cindy Kuzma, SELF, 28 May 2025

Word History

Etymology

estrus + -o- + -gen

Note: The word estrogen was originally a U.S. brand name for an extract of glandular tissue used in the treatment of ovarian dysfunction. Its producer, Parke, Davis and Company, relinquished rights to the name in 1936.

First Known Use

1927, in the meaning defined above

Phrases Containing estrogen

• estrogen replacement therapy
• selective estrogen receptor modulator

Kids Definition

estrogen

noun

es·​tro·​gen ˈes-trə-jən 

: a substance that tends to cause the development of secondary sex characteristics in the female and promote the growth and normal functioning of the female reproductive system

estrogenic

ˌes-trə-ˈjen-ik

adjective

Medical Definition

estrogen

noun

es·​tro·​gen ˈes-trə-jən 

variants or chiefly British oestrogen

ˈē-strə-jən 

: any of various natural steroids (as estradiol) that are formed from androgen precursors, that are secreted chiefly by the ovaries, placenta, adipose tissue, and testes, and that stimulate the development of female secondary sex characteristics and promote the growth and maintenance of the female reproductive system

also : any of various synthetic or semisynthetic steroids (as ethinyl estradiol) that mimic the physiological effect of natural estrogens

estrogen-like adjective

or estrogenlike

-ˌlīk 

an estrogen-like compound

estrogen-like effects