of course.....here's the differences
HGH....is exogenous, it's something that gives you artificially high levels of GH in slow wave pulses
GHRP-6/2... is a synthetic Growth Hormone Releasing Peptide....it increases the amount of GH production in each somatrope in the pituitary.
CJC/GRF..... is a synthetic Growth Hormone Releasing Hormone....these focus on increasing the AMOUNT of GH secreted by each somatrope in the pituitary
HGH REPLACES natural endogenous GH prodcution, while the other 2 STIMULATE natural endogenous production. When you combine a GHRP and GHRH, they work synergistically (much better than if either is used alone). If you time your injections right you can use all 3 or HGH with a combo of one other. The GHRP will give a big "pulse" that is short lived but repeated. HGH will give a smaller, slower pulse, but longer lasting. The GHRH is the wild card and will act completely differently whether used alone or with other analogues. See the cahrt below for an idea of how to use these. Personally, I would do the GH pin about 20-30 minutes after the GHRP pin.
*Graph taken from datbtrue.co.uk
This specific graph uses CJC-1295 which has a super long half life, and as you can see causes GH bleed and never reaches elevated levels. CJC-1293, also known as GRF (1-29) is a much better choice for a GHRH because of the shorter half life.
If you can afford it, run all three....if not, adding GHRP to your regimen will only help
I can't find a link that works for the study I got some info from, but here is the reference if you're interested in actually going to the library and reading
[2] Chen, C., Wu, D. and Clarke, I.J. (1996) Signal transduction systems employed by synthetic GH-releasing peptides in somatotrophs. J. Endocrinol.