This pre workout is the bomb. First time I tried it felt like I could work out for 4 hours non stop. I completed my whole workout but didn't feel like finishing so did a few extra exercises that weren't on the days workout list. I feel I've gotten used to it so it's not quite as effe give as the first use but it's still good. The sour candy flavor is pretty good too. I haven't tried any of the other flavors though.