NO PH's. You can try natural test boosters, but they might not do much. Short of steroids, your testosterone is at the highest it will be in your lifetime right now. With steroids, you're going to have some serious issues later in life.
I'm 19, no natty test boosters have really done anything for me. Out of everything, I would say a good multivitamin, fish oil, adequate protein intake, BCAA's, creatine, and beta alanine have done the most.
I buy my creatine and beta alanine in bulk and mix in with my 1 scoop whey pre/ 2 scoops post WO shakes. I use LG's BC +EAA during workouts, not because its superior, but because bulk BCAA's are nearly impossible to drink and mix. Don't waste money on expensive name brand "innovative" products.