Estradiol vs Estrone vs Estriol

There are three types of estrogens in the human female body and the boards usually likes to tease us with these various types.

Here's a quick encounter about these three hormones that should be enough for USMLE prep:

Estradiol: Is the young female's hormone of femininity. It's also called E2. It's prododuced by aromatization of Testosterone in the Graafian follicle (granulosa cell). It's the most potent estrogen with the highest effect on receptors.

Estrone: Is the estrogen of the menopause. It's produced by aromatization of androstenedione in peripheral (fatty) tissue. It's also called E1. It's less potent than Estradiol.

Estriol: Is the placental estrogen and it's only seen during pregnancy and it's high levels reflects fetal well being. It's also called E3. It's the least potent of all estrogens. It originates from the fetal adrenal gland in the form of DHEA Sulfate and then is finally transformed to Estriol in the placenta by the sulfatase enzyme.