Yohimbine is a dietary supplement that improves erectile function. It selectively blocks central and peripheral presynaptic and postsynaptic (in high doses) alpha2-adrenoreceptors. It has a stimulating effect on the central nervous system

>It selectively blocks central and peripheral presynaptic and postsynaptic (in high doses) alpha2-adrenoreceptors

So basically does it block adrenaline to go into the penis alpha2-adrenoreceptors constricting the blood vessels?