O and to the kid that is 17 and asked if he should take this- absolutely not. I believe its recommended to be at least 25 (at least thats how it is for Stak 2).
You have more than enough natural hormones at that age to make some good gains. Appreciate your youth- dont rely on supps to get you what you can achieve without them. Build a good base and supplement when you start getting older and you actually need to, they will be much more effective trust me!