After hearing lots of the people at boot camp rave about their increased energy, mid-afternoon boost, and increased focus with Slam, I decided to give it a try, even though Spark didn't do anything for me at all. So many people indicated it had "changed my life!" I figured I'd try it since it was a safe product to take. I was eager to see what effect it would have on me - the first try, no change. I figured that was okay, I'd try it again a different time of day. Again, no change. Folks warned it was so effective that, just as with coffee and other caffeinated products, they didn't suggest taking it after supper at he risk of not being able to fall asleep - how could this have zero effect on me? So I tried a few more times, still no change. I even tried doubling up - still no effect. I understand this works for lots of people, and I wish was one of them, but the reality is it's nothing more than a flavored drink for me. I was very disappointed. I had high hopes, but it simply didn't give me any energy boost whatsoever.