You are but a youth. Your body is making more testosterone right now than it ever will again in your life. You don't even know what is in the so-called "testosterone booster". You should forget such nonsense and concentrate on the basics of lifting big and eating right to take full advantage of the testosterone you have, rather than trying to take a silly supplement to try to get your body to make a little more.
This is what I wanted to say. If I could pack on a significant amount of muscle and size at AGE THIRTY-EIGHT
just by eating a bit more and doing basic lifts hard and heavy, why can't you do the same? There is roughly a 99% chance you've got more testosterone in your body than I have. I'm in the "too old" category. I do another sport that burns up calories like mad. I'm naturally skinny. I'm also very careful to avoid gaining too much body fat as I gain weight. Yet I still managed to get bigger without pro-hormone supplements.
You can go me one better.
Save your money. If you're going to spend it on anything, hire a good trainer, consult with a good nutritionist who knows how to get people big (John Berardi and Shelby Starnes spring to mind - and they're not that expensive), and go from there. They'll pay off more than any supplement possibly can...and you'll learn how to do it at will. Even steroids can't beat that.