I think its very fair to state that GH is released in pulses with the biggest boost at night. This is true for adults as well as children.
Or, as the Encyclopedia of Medicine 2002 version says:
"hGH is produced in the anterior portion of the pituitary gland by somatotrophs under the control of hormonal signals in the hypothalamus. Two hypothalamic hormones regulate hGH; they are growth hormone-releasing hormone (GHRH) and growth hormone-inhibiting hormone (GHIH). When blood glucose levels fall, GHRH triggers the secretion of stored hGH. As blood glucose levels rise, GHRH release is turned off. Increases in blood protein levels trigger a similar response. As a result of this hypothalamic feedback loop, hGH levels fluctuate throughout the day. Normal plasma hGH levels 1 -3 ng/ML with peaks as high as 60 ng/ML. In addition, plasma glucose and amino acid availability for growth is also regulated by the hormones adrenaline, glucagon, and insulin.
Most hGH is released at night. Peak spikes of hGH release occur around 10 P.M., midnight, and 2 A.M. The logic behind this night-time release is that most of hGH's effects are mediated by other hormones, including the somatomedins, IGH-I and IGH-II. As a result, the effects of hGH are spread out more evenly during the day."
See attached chart for adult males.
I do agree on the importance of !GF-1 (somatomedin-c)......which is responsible for muscle growth. IGF-1 stays in plasma for up to 36 hours.........endo-hGH's half-life is 20 to 25 minutes.
Exo-hGH does stimulate IGF-1 levels, but a higher percentage is bound and not bio-available. Also impacted negatively by large doses of exo-GH are the hormones insulin and T3. So the serious bodybuilder practices a little polypharmacy by stacking steroids (for IGF), insulin and T3 with the GH........to overcome the body's natural defense mechanisms.
I'm a big fan of Depot. I believe that it's release pattern lessens the negative feedback of the endocrine system. Otherwise, sure, split up the dose throughout the day of regular GH.