I would start it as soon as possible sense it would take a while to really kick in anyway. I started feeling the g at about 1-2 months in, hands numb and arms numb. But to really see the best effects i would recommend at least 6 months. Make sure you are getting quality g. There was a huge difference in progress when i actually got decent stuff. I have been running 5-10 ius a day for about 5 months now and see very little as far as losing gains when i get off of cycle
I used gh during a pct once..It makes the pct time easier for sure
It does, but the cost of the cycle is 1/5 of the GH.