I ran 10iu's 5 on/2 off for about 7 months and never felt better. I was originally running 6iu's for about a year prior to that, but my HGH started coming in under dosed, so I bumped it to a vial a day.
Never felt better in my life than I did during that period. Tons of energy, skin was vibrant and clear and slept like a rock.
The only reason I stopped taking it was that my source went from fucking awesome, to so-so to downright unreliable.
If my source didn't flake on me, I'd still be running 6iu's 5 days per week.
Best product I've ever taken in my life. I don't necessarily think I added much muscle, but I stayed incredibly lean and I've never felt better and healthier in my life than I did while on GH.