For me, Powerfull DOES affect my sleep.
I only took 4 before bed everynight.
I would fall asleep very nicely.
However, at about 2 weeks later, as I started to feel more energetic (and horny), I felt that even though I could fall asleep quickly, I could not manage to sleep for long.
I would sleep from 12 midnight to about 4 am, then I would wake up and toss and turn, before falling asleep with great difficulty again. And then I would wake up at 730am and could not sleep anymore, feeling quite "hyper" and energetic and horny. hehe.
I am take a break from Powerfull, for about a week, before taking it again.
Anybody else have the same problem as me with powerfull?