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Understanding Estrogen: Estrone, 17β-Estradiol, Estriol, Belly Fat and Menopause


Estrogen is a family of hormones with several members, including estrone, 17β-estradiol, and estriol, each with distinct roles in the human body. This article explores the production and influence of estrone, 17β-estradiol, and estriol on fat distribution, as well as how these hormones are affected during menopause, including the shift from 17β-estradiol to estrone and the unique role of estriol.

1. Estrone, 17β-Estradiol, and Estriol Production

Estrone, 17β-estradiol, and estriol are three essential estrogen hormones produced in the body. These hormones are synthesized primarily in the ovaries, but they can also be produced in various tissues through a process called aromatization, where androgens are converted into estrogens.

2. Estrogen's Influence on Fat Distribution

Estrogens, including estrone, 17β-estradiol, and estriol, play a crucial role in regulating fat distribution in the body. Women typically have a higher percentage of subcutaneous fat (fat under the skin) and a lower percentage of visceral fat (fat around organs) compared to men. Estrogens help maintain this distribution.

3. Estrone, 17β-Estradiol, Estriol, and Fat Distribution

- Estrone: It contributes to fat distribution and helps preserve the subcutaneous fat layer, contributing to the characteristic fat distribution seen in women.

- 17β-Estradiol: This hormone is particularly potent and has a more pronounced influence on fat distribution. It helps maintain a healthy ratio of subcutaneous to visceral fat, promoting a feminine body shape.

- Estriol: Estriol is a unique estrogen primarily produced during pregnancy. Its role in fat distribution is less understood, but it is known for its role in maintaining a healthy pregnancy and supporting fetal development.

4. Shift in Hormone Production During Menopause

During menopause, there is a significant shift in hormonal production. Before menopause, 17β-estradiol is the predominant estrogen hormone, contributing to the maintenance of female secondary sexual characteristics and overall health.

However, as women enter and progress through menopause, ovarian function declines. This results in a reduction in the production of 17β-estradiol, the potent form of estrogen. Consequently, estrone becomes the more predominant estrogen hormone during menopause, with a decrease in estriol production.

5. Menopause and Fat Distribution

The hormonal changes during menopause can affect fat distribution. As 17β-estradiol levels decline, there can be an increase in visceral fat, including belly fat. The shift from 17β-estradiol to estrone as the predominant hormone may contribute to changes in body composition, and the role of estriol in this context is still an area of ongoing research.


Estrone, 17β-estradiol, and estriol are vital members of the estrogen hormone family, each contributing to fat distribution and overall health. Understanding how these hormones are produced and their influence on the body, especially during menopause, and the unique role of estriol, is essential for managing changes in body composition and overall health during this life stage.

By Dr Purity Carr

GP & Menopause Doctor

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