IMO, unless your planning to go compete, dont do it and wait until your 21. But, if your diet, training, sleep/rest/recovery, and finances,research, patience, and goals are in check, DO IT. I would almost want to add genetics in the check list but with only 8 months in, it might be too hard to tell yet. A lot of the great ones started off early, and they all had the check list down to the T ie<Sergio Olivia, Shawn Ray, Phil Heath. Good luck with your decision.