c'mon guys let's give this poster some respect, he wanted serious answers to his question.
i would think somewhere along the lines of working out hard,seriously, correct diet, and not getting into age, genetics, etcetera, at least 5 years on upwards to 10, regardless of natural or juiced. but i also agree that from light heavyweight on up, (the big boys) it ain't going to happen if your not juiced, you have to even a little bit and more likely alot.
like i mentioned it's hard to say dependent on age, your genetics, how smart you train, consistency in training, etcetera.
but here's hope: after about 3 years of hard solid, bust ass eating right and supplementation (whether natural supps or juice) and training, to the general public you would be though of as "huge, swole," and on juice even if your aren't! so even if you never get to be top 10 national npc competitor shape/size to 90 percent of the public you will be perceived as such! from there it's up to you in the next coming years to get to your goals. good luck!