OK, it does everything they claim. I've been drinking coffee for years, the crash from coffee is a true crash. You feel sluggish, tired, and less aware.5-hour is just what they say. you are extremely alert (meaning your level of awareness is heightened) there are NO jitters, No nervous energy, No hyper boost. Just a steady feeling of "Yes I can", "no problem let's get it done." 5 hours after you've started your not tired, you just continue about your day as normal. I am aware that the extra "extra" is no longer present, but I am not tired!My General purpose is for when my day at college is over (3pm). I drink one 2oz bottle and do the reading necessary and home work. I have also used it during a coffee crash around 1pm from my two cups at 7am and 8am. The 'crash' disappears and I finish my day wonderfully.