"Very different" is a strong word. They're more similiar than different and both have similiar intermediaries within the body. Thankfully, that difference is largely the difference between long-term debilitating addiction and short-term focus.
Ive taken two different amphetamines and 1 brings on panic attacks and the other doesn't. I call that very different. The molecule doesn't have to be that different in order to be vastly different in what it does to humans.
Two street amphétamines or two prescribed? Sorry not trying to be rude, but you know there seem to be like 4 in Aderall, so how do you tell them apart?
Besides you can be absolutely sure there is very clean stuff out there on the streets.
All I’m saying is that bros are effectively micro-dosing to cater to condition and there are lots of people taking this in very regular manner.