I used to work at a corperate GNC and we did sell a lot of t-bomb, however the benefits are few and far between. Yeah it will put you into a deep sleep, but you can also come out of it kinda groggy. Save your money. Secondly, I'm a first year medical student and yes water retention can help increase the sacromere but at the molecular level and not really enough to see any visible benefit. Also 15 in my opinion is kinda young to start supplementing with hardcore stuff. At GNC you had to be 18 to buy this anyway. Secondly I can speak from experience as to the negatives of supplementing hardcore stuff at such a young age. Just take a really good multi vitamin, calcium, and protein and let your young muscles develop properly. Becides, after the prohormone ban, anything that you can buy over the counter at a GNC (medicaly speaking) really won't do much unless you have hit a wall and need a little bit of push.