1st cycle timing

ive been training on and off for roughly 4 or 5 years...im 21 now...most recently this past year i have completely dedicated myself to training and dieting while supplimenting with protein powders, creatines and l-glutamine...and have on occasion tried an andro or test support formula...in the past year my gains have been huge but i have seen a possible slowing of growth or decline in speed of growth...and more recently have been considering my first cycle and researching it fully...now with this in mind i know my genetics are good and have been told so by quite a few ppl...with this in mind...how can i tell if i can when i have reached my genetic potential or maxd my growth without the use of AS?

when you hit a plateau....you stop gaining in strength and mass. you'll know when you hit it.

congrats on the natural gains btw!

some stats:
chst-45in
bicep-17
waist-32
all natural so far...

I'd say you still have some natural growth left to do.
Don't be in a hurry to jump into cycleing cuz for your age your stats are pretty dam good.
If you do decide to take the plunge make sure you research before doing so.
Goodluck,

those are some very nice stats for being natural...but i bet your dedication over the past few years played out in it too. like the others said, you will know when you hit your plateau. gains start slowing down and then just flatlines....... and if you do start AAS, i bet you'd respond to some very nice light doses of test and dbol. good luck with your decision.