don't even think about it until your 21... is faster gains in the gym really worth messing your body up for the rest of your life?? it wasn't to me, and besides, natural gains with a little extra work look 100% better in my opinion. pro-hormones make you look bloated, you put on a "wet" muscle look, and you will lose most of the gains you made of cycle anyways... don't be afraid of hard work...