I actually really like Pro Xanthine better than most of the other similar products I have taken, and I'll tell you why! I am not big on that intense stimulated energy stuff, I am hyper enough, I don't like the feeling of my heart trying to beat out of my chest. So with that in mind, and needing a little pick-me-up just like the rest of the normal population, I choose Pro Xanthine. So I have found that Pro Xanthine gives a more clear, focused mental stimulation rather than a physical one. As a matter of fact, we use the exact same stimulant in our N.O. Ignite that everyone raves about, no jitters, extreme mental focus, same thing just in a more potent dose designed to last approx. 4-8hrs! I know that is a big range, but it is one of those things where you get used to it just like anything else, so the first time you take it, you are an 8hr guy who only needs to take one in the morning and it lasts all day.... as time goes on, you will take one in the morning and then one around noon and your good til you get done with your day! So if you are a stimulant junky, not gonna be your favorite product, will seem weak! If you are not a stimulant junky and just want some extreme mental focus and feeling alert, then this is your product!