i used to tolerate stims pretty good..hell i used 3 scoops Jack3d at one time (OG formula), with no issues..
them days are long gone. i have weened myself of stims pretty well, and avoid overdoing them, cycle them too of course.
hell i haven't done a fat-burner or pure energy-type compound since my prep for last July show, and went away from the preWO products too for couple months.
yes, it hit me hard today.