Ran through my fair share of nubain as well. Could tell the story but I am sure you already know it. I will say Kratom is nothing like Nubian. Know some people have a problem with it(Kratom) but not all. Yes I have seen people who cannot handle Kratom and wind up with an expensive habit. Others like me get sidetracked by slin/growth/intra shake and forget to take it and wonder why my workout was a little off. The ones that seem to have the most problems I have seen always take more and more to get a desired effect. I am guilty of it myself but reached a point to where I took it as far as I was willing to go. Still get increased focus, mild pain killing effects, and energy and from it but just not as zoned out. It's a good preworkout sup imo but you got to know your limits....some don't but I always haven't either.