I've had crit problems on/off in life (sleep apnea and just genetically sit at at op range - outside of tests numbers it's never caused any issue though). Hgh between 2-4iu for a year plus and I haven't noticed a significant change. Maybe on a heavy blast I'm more susceptible (talking 1-2pts max if true). Maybe 4 blood tests during this period and 3 blasts. I seem to have increased resting heart rate though... testing that now.