i tend not to worry either, but as youve asked id say having heart, liver or kidney problems concerns me, being infertile is not a good thing by any means. i plan on gaining another 30lbs of muscle in the next 5 years (preferably less) before im 25, whilst staying below 15% bodyfat. saying that is one thing, but like already mentioned, if/when i get to that, im likely to not be happy with my size and want to get bigger still. hopefully, for the sake of my health and wardrobe i will not try for much more size than that. i would like to acheive this without using GH, but i love treating myself as a science project, in a non-reckless way