I tried my new bottle of RPM this morning. I am on a tight budget for supps, so I try to make them as long as I can, while still trying to make them effective. I took two RPM's with my morning workout drink--Creatine/Aceytl l Carnintine. I could definately tell a difference in my workouts. I was not a raging animal or anything like that, but I seemed to have more endurance and focus, plus I did work out harder than usuall. I'm sure if I took four I'd be throwing the wieghts around like a mad man. Now I have some samples of DRive to try. I may need to order first because I'm sure as soon as I try Drive I'll want to keep taking it.