CJC-1295 (No DAC) + GHRP-2

Adding CJC-1295 without DAC gives this design a second receptor to work on. That analogue, usually sold as Modified GRF (1-29), is a 29-amino-acid GHRH fragment with four substitutions that stop dipeptidyl peptidase-4 from cutting it, and it binds the GHRH receptor instead of the ghrelin receptor. Both receptors are expressed on the same somatotroph but are controlled differently, so giving the two together lets researchers test whether their responses simply add up.

GHRP-2 is a synthetic hexapeptide, D-Ala-D-2-Nal-Ala-Trp-D-Phe-Lys-NH2, also registered as pralmorelin and KP-102. It comes from the growth hormone-releasing peptide series developed before ghrelin was known — the compounds whose then-orphan receptor was later named GHS-R1a — and it contains three non-proteinogenic residues, two being D-amino acids, which is what makes such a short sequence stable enough to use. In the 10 mg vial it is co-lyophilised with CJC-1295 (No DAC), 5 mg of each; with molecular masses of 817.97 and 3367.93 g/mol, that 1:1 split by mass delivers about four hexapeptide molecules per molecule of GHRH analogue. Compared with ipamorelin in the neighbouring blend, GHRP-2 releases more growth hormone but is less selective.