I finished up a log today one month for this. I have used some of their products in the past and enjoyed them. This is one of the best otc products i've used in a long time. My aggression was the best thing I noticed. I was getting snappy which isn't normally me but using it in the gym. Even hitting pr's with today on last set of inclines 295 lbs for 2 reps. Solid strength gains and mood elevation.