So lately I have been ordering alot of stuff and as a result, getting a ton of free samples . I had about 4-5 packs of Neurostim sitting around so I decided to give it an honest try. I had taken 1 of each (the caffeine one and non-c one) seperately and it didn't do jack at all except the caffeine one made my breath taste like fart (dead serious). So I was running late to work so I thru together the C one and the non-C one with about 8oz of Sprite. The fizz was scary high for multiple minutes, so I downed it anyways. Still tasted like crap so I finished it all in 3 quick gulps. Ok, so now at work like 10 minutes later I think I'm feeling it. It seemed to reduce anxiety a bit, but didn't really help me focus. I really didn't feel anything wonderful going on in my brain. I would say there was a slight feeling. Anyways, it wore off soon. I dunno, I guess this stuff just doesn't work for me.