I would never have tried this except I found it for 13.50 for 16 packs at gnc. Well I have to say, I am highly impressed. It gives you a good mental and physical boost with out the over the top cns stimulation, and also gives very impressive pumps and quicker recovery. It has methyl b12 along with a fizzy delivery system that really seems to work as far as getting the nutrients into your system fast and effectively. I will be looking on the soon-to-be-outdated racks at supplement stores for more. The way I feel great all day after taking it, I wish I could take it everyday(if it doesn't stop working so well after a few days(it says take only on workout days)).