Ive been taking 5 rpms pre workout for awhile and love it. However today i was really feeling sluggish so i thought id try tossing a 25 mlg ephedrine hcl in the mix. It was amazing, i was AMPED! ive takin a ton of ephedrine in my day and alot of different stims but this was by far the best ive ever had. Focus and energy through the roof and i didnt crash when it was over. lasted about 4 hours for me. Love it.