Official websites use .gov
A
.gov website belongs to an official
government organization in the United States.
Secure .gov websites use HTTPS
A lock (
) or https:// means you've safely
connected to the .gov website. Share sensitive
information only on official, secure websites.
Schematic representation of biosynthesis of estradiol (E2), estriol (E3), and estrone (E1). E2, with the highest affinity to ERs, is primarily secreted by ovarian granulosa cells in premenopausal women. E1 and E3 are the metabolites of E2, both of which are much less potent than E2. Besides, E1 is the main estrogen after menopause synthesized in peripheral adipose and skin tissue, while E3 is mainly produced by the placenta in pregnant women.
