I started with the lowest dose to test tolerance. After experiencing nothing at all, I tried the maximum suggested dose of three scoops (which would make this not cost-effective). I felt a niacin like flush but not much else. No energy boost, no enhanced pump - or at least not significant. If you spend money on a supplement that claims so much, you should at least see it at maximum dosage. You couldn't tell the difference between this and having yams and water throughout the day - except for the tingle. One last thing, this came to me all caked up like a rock. Had to break it up.