the first time i took it there was a period of like 20 min where i couldnt get rid of an erection, it fuckin hurt it was that strong too. Side effects were horrible too, I could barely keep my eyes open, my head was about to explode and I could barely sit down because of muscle ache. I'm pretty sure I overdosed but I got used to it and it became a good friend of mine. Sideffecets went away.