But seriously though guys, to get back to the OP.
Carhartt may have started young and made some good gains, and that is well and good. The bottom line is that he is ONE PERSON, and one person isn't representative of the entire population. The vast majority of bros who start young without a solid foundation regret having done so.
When it comes to steroids, and your health in general, the most conservative approach is the best. Life is a marathon, not a sprint.
There are many things you can tweak in your diet, training, rest, supplementation protocol before you resort to exogenous hormones, and I suggest you do so.
If you want to know the effect of androgens on young guys, just google it. Don't look to the opinion of one person who has done okay, consider the vast majority of guys who now have low natural test because they started too early, and chemically aren't even men.