Contrary to popular belief, more is not better when it comes to exogenous GH use for fat loss.
There is a ceiling on lipolysis, and the highest GH dose for maximizing fat loss per administration is much lower than most people think.
As you can see here in the following study assessing the pharmacokinetics and acute lipolytic actions of GH, there were significant dose-response effects when comparing the incremental area under the curve of both free fatty acids and blood 3-hydroxy-butyrate following 0, 1, and 3 mcg/kg GH, whereas there were no differences between the responses following 3 and 6 mcg/kg GH [R].
These dosages were administered intravenously.
1 mg of Somatropin corresponds to 3 IU (International Units) of Somatropin [R].
So, this means that for someone who weighs 100 kg, lipolysis is maxed out at about 300 mcg of Somatropin, which is 0.9 IU’s of pharma grade GH IV.
We need to math out the corresponding subcutaneous dose based on the bioavailability and bioactivity comparison data we have on humans administered HGH.
Obviously IV dosages are not representative of what dosages would be via the far more realistic and tolerable method of administration (subcutaneous).
In one study, the mean estimated availability of subcutaneous injected HGH was shown to be 63% of that of HGH administered I.V. after correcting for differences in the GH dose [R].
Another study found the availability of subcutaneous injected HGH to be about 70% of that of HGH administered I.V. [R].
So, for a 100 kg man, fat loss benefits would be maxed out around 1.35 IU of GH per administration subcutaneously.
There is a refractory period cells need before another pulse of exogenous GH can even be useful in a lipolysis context, which I will delve into further in a future article.