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

Her official diagnosis was progesterone and estrogen-positive, HER2-negative invasive ductal carcinoma (IDC), which is the most common form of breast cancer, accounting for 80% of all breast cancer diagnoses, according to John Hopkins Medicine. —Meredith Wilshere, PEOPLE, 18 Apr. 2026

Try estrogen spray, which also can be applied on the arm or thigh. —Laura Trujillo, USA Today, 17 Apr. 2026

Recurring UTIs are common for women in midlife during perimenopause and menopause as the decline of estrogen becomes a key risk factor. —Alexa Mikhail, Flow Space, 14 Apr. 2026

Using its electronic health record database covering more than 130 million patients in all 50 states, Truveta found use of most forms of HRT has climbed in recent years, with the sharpest ​increase a 184% jump in estrogen patches since 2023. —Reuters, NBC news, 9 Apr. 2026

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