Well, as you well know all of these pre-workout supplements use quite a bit of caffeine >> this is why you get all that energy along with other stimulatns >> they force your brain to release epinephrine and norepinephrine....
However, you body will build up tolerance to it and addiction of course. You can try the following:
I. Cleanse your system & liver for couple of weeks >> use things like Milk Thistle, NAC, Butcher's Broom, Roibos Tea, Lots of Fiber...do a search on AM and you will find lots of stuff & of course limit or do not use any stimulants during this time. Once you start using them again, you will feel the difference for sure.
II.To have enough energy in the gym without stims >> eat a whole food meal with low GI carbs about 60-90 minutes before working out (about 40Protein and 60-100Carbs). If you want higher testosterone levels >> take approx. 3 minute breaks between sets. If you want higher Growth Hormone levels >> take a powernap(no more than 40 min) before gym and take about 60 secs before sets.
III. You can also make your caffeine last longer using things such as naringin (citrus binoflavonoid) >> this will increase the half life of caffeine since it inhibits the the cytochrome P450 oxidase enzyme (CYP1A2).
Besides that I do not think they have changed the formula in SuperPump, however, do you mind listing the ingredients on your bottle.