Why build muscle fast? Why not do it slowly, it is better to work at it, something good takes time, effort and work, who knows what that stuff will do to you in later life. Look at jack lalane and how old he is, he did not take a bunch of pills, he worked at it, dieted and exercised and he still looks great for his age. Please do not get me wrong, I am not judging you,
goodluck!