alcohol is not what is known as an active ingredient at least in this case.

Air is 78% nitrogen which does nothing for us
It is 19% oxygen which we need BADLY
but 100% oxygen is toxic to us, so we need to water it down with something, like nitrogen

Your estrogen is diluted by the same logic. 750 micrograms ain't much and if you tried to eyeball it in powder form you'd probably overdose by several orders of magnitude