What does estrone mean?
Estrone is a steroid hormone belonging to the estrogen family, the group of sex hormones primarily responsible for the development and maintenance of female reproductive tissue. Chemically designated C₁₈H₂₂O₂, it is one of the three major estrogens naturally present in humans, alongside estradiol and estriol. Estrone is notably weaker than estradiol, the dominant estrogen of the reproductive years, but it takes on greater importance after menopause, when ovarian function declines and fat tissue becomes the chief site of its production by converting androgens into estrone. Because elevated estrone levels have been studied in relation to breast cancer risk and bone health, the hormone features prominently in endocrinology and oncology research. The term derives from 'estrus' — ultimately from the Greek oistros — combined with the chemical suffix '-one', indicating a ketone. It appears almost entirely in clinical and scientific writing, often as part of measured values such as serum estrone levels.
nounAn estrogenic steroid hormone (C₁₈H₂₂O₂) produced chiefly by the ovaries and, after menopause, by adipose tissue; it is one of the three major naturally occurring estrogens in humans and is weaker than estradiol.
- (Biochemistry) A weak estrogenic steroid hormone, C₁₈H₂₂O₂, secreted mainly by the ovaries and adrenal glands and, after menopause, converted from androgens in adipose tissue; it is one of the three principal endogenous estrogens in humans.
- (Pharmacology) A preparation of this hormone used in hormone replacement therapy and certain other treatments.
"After menopause, estrone becomes the predominant circulating estrogen in a woman's body."
"The researchers measured serum estrone concentrations across all participants."
"Because adipose tissue converts androgens into estrone, body fat becomes a major source of estrogen after menopause."
Rarely pluralized; used mainly to refer to multiple molecular variants or synthetic analogues of estrone.
"Several synthetic estrones were tested for receptor-binding activity."
Named partly after the Greek word for 'frenzy' — oistros was the gadfly that drove cattle mad, giving us both 'estrus' and 'estrone'.
Reviewed by Deb Chak, Editor. AI-assisted content curated by RJS Tech Solutions LLP.
Etymology of estrone
The word 'estrone' combines 'estra-', from estrus (the reproductive cycle of female mammals), with the suffix '-one', used in chemistry to denote a ketone. 'Estrus' itself comes from the Greek oistros, meaning a gadfly or sting, later extended to describe the frenzied behavior of animals in heat. The hormone was identified in the late 1920s, during the period when the first pure estrogens were being isolated, and British usage retains the older spelling 'oestrone'. Its relatives include estrogen and estradiol, which share the same root.
How estrone is actually used
A technical term used almost exclusively in medical, biochemical, and pharmacological contexts; it is rarely encountered in everyday conversation. In British scientific writing the spelling is often 'oestrone', reflecting the retained 'oe-' diphthong.
Easily confused with estrone
Estrogen is the general term for the class of female sex hormones, whereas estrone is one specific member of that class.
Estradiol is the most potent natural estrogen produced during reproductive years, while estrone is a weaker estrogen that predominates after menopause.