Two words: NIACIN FLUSH
This is an excellent product and a great all-in-one (minus creatine, but, that's inexpensive to purchase separately) with only one flaw I can find: Way. Too. Much. Niacinamide. Niacinamide is touted as the "no-flush" Niacin, but I think they have managed to put so much into one serving that even someone who is used to daily Niacin supplementation could easily get a niacin flush depending on the kind of exercise they do. I, personally, was doing push-ups when my face lit up red and felt painfully itchy/irritated. Knowing what a niacin flush feels like from prior experience, I checked the label after my workout and saw "Niacinamide: 75g (469%)" which seems unnecessary.<br /><br />That said, this stuff is otherwise excellent and I'll probably keep using it anyway. I had great focus and endurance, the flavor was good (I went for "Pina Koala"), it seemed to mix fairly easily in roughly 8oz of cold water, and I have no complaints whatsoever except for what I mentioned above. Since I'm rating both the product and the experience, though, and since I'm going to spend the next several workouts with a burning itchy forehead until/unless my body acclimates to such ludicrously high dosages... that's enough to lose two stars by itself.
Rating: 3 stars