Using it right now. I'm in my first week.
More acne, increased aggression

, trouble sleeping, disturbed dreams where I rip someones arm off.
Increased output in activity and musuclar volume. Longer gym sessions with less fatigue (dunno why)
Just using one a day instead of the recommended two. But since this stuff works when you sleep it's hard to say what it's doing because I can't sleep.
Right now I'd buy it again because I like it so far. I'm no doctor and neither is the guy who sold it to me, but taking it if you are under 25 just sounds risky. You must be under a lot of presure.