Modified Growth Releasing Factor aminos 1-29, usually referred to as Modified GRF (1-29) or “ModGRF(1-29),” also known as CJC-1295 without DAC, is a synthetic analog of the endogenous peptide signaling hormone Growth Hormone Releasing Hormone (GHRH). Endogenously produced GHRH has 44 amino acids in its chain structure. A truncated synthetic form of GHRH called Sermorelin or GRF 1-29 has 29 amino acids; Modified GRF (1-29) is further changed in that it has four substituted aminos in its chain that serve the purposes of preventing degradation and oxidation in manufacture and transport as well as in vivo, while also increasing binding affinity to the GHRH receptors.
Modified GRF (1-29) is not CJC-1293 nor should it be referred to as such. Modified GRF (1-29) is identical to the portion of CJC-1295 DAC that is not bound to MPA, minus the lysine. The presence of lysine in a literal “CJC without DAC” in the absence of MPA would have the opposite effect of DAC: it would drastically reduce the active life of the peptide to that of Sermorelin. Modified GRF (1-29) is the same as CJC-1295 with out DAC.
Tetrasubstitued GRF (1-29)
Modified GRF (1-29) is a synthetic modification of growth hormone releasing factor (GRF) with D-Ala, Gln, Ala, and Leu substitutions at positions 2, 8, 15, and 27 respectively. These substitutions create a much more stable peptide with the substitution at position 2 to prevent DPP-IV cleavage, position 8 to reduce asparagine rearrangement or amide hydrolysis to aspartic acid, position 15 to enhance bioactivity, and position 27 to prevent methionine oxidation.
CJC-1295 DAC vs. CJC-1295 No DAC
CJC-1295 DAC and CJC-1295 (also known as Modified GRF 1-29) are both Growth Hormone Releasing Hormones (GHRH). Their action in the human body is identical but the difference between the two peptides are the span of the half-life. Modified GRF 1-29 and Sermorelin have a very short acting half-life of about 30 minutes, while CJC-1295 DAC has a half-life that can last up to approximately 8 days. Many a scientist have reported that the short half-life of Sermorelin and Modified GRF 1-29 is considered to be much more natural as they produce a short pulse of Human Growth Hormone.