? I don't follow.

I thonk a lot of people underestimate the PROFOUND effect that even very small amounts of certain compounds can have.

LSD, Blowfish toxin, most drugs (of which most pills are filler), hormones etc.

Estrogen (and other hormones, as guys have estrogen and women have testosterone) plays a rather large role in the body and the brain.

To what end when it comes to gender identity in a body that was not yours at birth, I cannot say.