Serum Growth Hormone

When elevated (on exogenous GH):

• Serum GH is highly variable -- it depends entirely on timing relative to last injection
• Peak serum GH: 1-3 hours post-injection (subcutaneous), levels can be 20-40+ mIU/L
• Trough: 8-12h post-injection, returns near baseline
• A single elevated reading on exogenous GH is expected and not clinically actionable
• IGF-1 is the correct marker for monitoring GH dose adequacy -- it reflects integrated 24h GH exposure

Timing of blood draw matters:

• For GH "serum check" (confirming GH is real/active): draw 2-3h post-injection; expect elevated levels
• For IGF-1 monitoring (dose adequacy): draw 12-24h post-injection in fasted state
• If serum GH is NOT elevated 2-3h post-injection, the GH product may be underdosed or fake

When LOW (off exogenous GH):

• Single fasting GH <1 mIU/L is normal for adult males -- GH is pulsatile and mostly secreted during sleep
• A single low reading has limited diagnostic value
• If GH deficiency is suspected: requires stimulation testing (insulin tolerance test, GHRH-arginine test) performed by an endocrinologist -- not a random blood draw
• Symptoms of GH deficiency: poor body composition despite training, impaired recovery, poor sleep quality, reduced bone density

Supporting natural GH secretion:

• Optimise sleep -- majority of GH is released during deep (Stage 3/4) sleep
• Fasting -- GH increases significantly during fasting states (12-16h)
• High-intensity exercise -- resistance training and HIIT acutely spike GH
• Minimise pre-bed carbohydrates -- insulin blunts GH release
• Arginine -- 5-9g before bed on empty stomach (may augment nocturnal GH pulse; modest effect)
• Melatonin -- 0.5-3mg before bed (improves sleep quality, may indirectly support GH release)
• Maintain low body fat -- adiposity blunts GH secretion

References:

• Kanayama, G., Hudson, J. I., & Pope, H. G., Jr. (2008). Long-term psychiatric and medical consequences of anabolic-androgenic steroid abuse. Drug and Alcohol Dependence, 98(1-2), 1-12. DOI: 10.1016/j.drugalcdep.2008.05.004