Takes about 6 months to really take hold in your system and do it's magic. Once you pass that 6 month mark you can go off of it for a few weeks at a time before it burns up, but it will still linger in your system during the time off. A MLB player to get real benefits off of it will have to keep the IU's coming daily all season. So it really becomes a Russian Roulette situation. Do it and hope they don't call your number or don't at all and hope your body doesn't fall apart.
SIde effects while on HGH include bone growth that is mostly noticed by teeth becoming gapped, elbows and knees becoming more knobby and a forehead that blots out the sun.
When you come off of it, a big tale tell is a big hard gut... So we shall see. We shall see.