T Nation

Questions about Estrogen

I have a few estrogen-related questions, and they’re more to do with properties of the hormone itself.

In men, E2 is only produced via aromitazation, correct?
How are estrone / estriol produced and why are they unimportant relative to E2?
In men, is measured E2 mostly unbound? I know SHBG can bind to estradiol, but has a much higher affinity for testosterone - when you measure total E2, are you basically measuring bio available E2?
What other hormones can cause sensitivity in the nipples if E2 is under control? Prolactin? Progesterone?


@KSman? Anyone? Bump.

Seriously? Bump again.

E2 is the product of T–>E2 and is the main focus. E1 and E3 are typically side shows. We can control E2 and get good results.

E1 - estrONE
E2 - estraDIol
E3 - esTRIol

E2 does not provide any kind of measure of T.
E2 opposes the effects of T
E2 increases SHBG that decreases FT. So FT:E2 take a double hit.

We do not seem to have a need to worry about fE2 vs E2+SHBG
E2+SHBG is bio-available, T+SHBG is not

There is a Estradiol sticky found here: About the T Replacement Category

Also see: https://en.wikipedia.org/wiki/Steroid_hormone

Thank you KSman, that helped a lot actually.