Personally, I've been taking RPM for about year or so. I used to take AMP at the dosage they recommended at that time. I was taking it when it first came out...so that was ONLY a pre-workout supplement. Even with taking AMP on my workout days, I was getting the jitters. I stopped taking that for that reason. That's when I started with RPM and I never had the jitters. I have had a "euphoric" feeling at times, but never jittery. Definitely more "aware" of things and "psyched", but that's it. When I added drive, I just lowered my dose of rpn in half. Still no problem. The only difference is that I never smolked in my life(outside a puff here and there when I was younger while being drunk). Although you don't smoke on the days you work out, the Nicotine is still in your system. So...I say either wait it out, stop smoking or talk to a doctor, get some medical advice about the effect of nicotine.