Modified GRF 1-29 (AKA Mod GRF 1-29, CJC-1295 without DAC)
Half Life: 30 minutes
Overview and History of Modified GRF 1-29 (CJC-1295 without DAC)
Modified GRF 1-29 is also known as Mod GRF 1-29, but even more commonly known as CJC-1295 without DAC. The proper terminology, however, is its original name and classification: tetrasubstituted GRF (1-29). The confusion in regards to the naming and nomenclature of this particular substance must be first clarified before delving into any further discussion, as the majority of performance enhancing drug community and individuals looking to use this substance will undoubtedly become very confused upon reading and researching this product, and especially later on when electing to purchase it (it is listed under all of its names by some vendors and only one of its names by other vendors). The name Mod GRF 1-29 was originally derived by a researcher known as DatBtrue, who coined the term in his internet publicized articles on the substance. Because of the popularity of his articles, the new name was easily and extensively adopted by readers, and the common use of the name spread wildly from there. However, perhaps the most common name for this substance is CJC-1295 without DAC. The importance to understanding the difference in these names is the history of the substance and its structure.
Mod GRF 1-29 belongs to a category of peptides known as HGH (Human Growth Hormone) secretagogues. It is a modified derivative of an already existing derivative of Growth Hormone Releasing Hormone (GHRH), which is an endogenously produced peptide hormone in the human body. Therefore, it could be referred to more properly as a second generation derivative of GHRH. GHRH is modified to create what is known as Growth hormone Releasing Factor (GRF) 1-29. GRF 1-29 is then further modified to create Mod GRF 1-29. The nomenclature of the evolution of the derivatives should be self-explanatory concerning this. GRF 1-29 is also known by its trade name, Sermorelin (which Mod GRF 1-29 is a derivative of).
The most popular name for this peptide, however, is CJC-1295 without DAC, and is referred to as such because there is actually a third derivative of GHRH, which is known as CJC-1295 with DAC. The acronym DAC stands for Drug Affinity Complex, which is a modification that is added to the peptide that extends its half-life and active life in the body. CJC-1295 without DAC is simply Mod GRF 1-29.
For ease of explanation and clarification to the reader, what has been discussed thus far is the following:
Now that the confusing naming system has been clarified, the general description of Mod GRF 1-29 is as follows: Mod GRF 1-29 is a peptide hormone (also known as a protein hormone) that was developed in Canada and first mentioned in medical literature in 2005[i]. It is a protein that is 29 amino acids long, and as explained earlier, it is a GHRH analogue. As a GHRH analogue, Mod GRF 1-29 (CJC-1295 without DAC) acts on receptors at the pituitary gland to stimulate the release of Human Growth Hormone. In order to understand its function and what it is, one must understand the concept behind the protein/peptide structure of these hormones (which will also consequently help the reader to further understand the difference in the naming that has been discussed above).
Proteins/peptides are chains of amino acids linked in specific unique orders. Proteins, depending on how many amino acids it is composed of, will manifest itself as one of three structural types: the primary protein structure which is simply a long chain of amino acids, the secondary protein structure which is a folded protein structure resembling a pleated sheet, the tertiary protein structure which is a complex fold of proteins that resembles a tangled ball of yarn, and finally the quaternary protein structure which is several tertiary proteins interconnected. The significance of this in protein hormones such as Human Growth Hormone (HGH), insulin, Luteinizing Hormone (LH), Mod GRF 1-29 (CJC-1295 without DAC), and many others, is the fact that various sections of the protein structure will contribute to different jobs in the body by binding to and activating different receptors. The shape of the peptide hormone, and the different subsections of it, can allow stronger binding affinity or weaker binding affinity.
Growth Hormone Releasing Hormone (GHRH), which is the endogenously secreted GHRH by the arcuate nucleus of the hypothalamus of the human body, is 44 amino acids long. It was discovered, however, that only the first 29 amino acids of the protein were equally as effective in binding to receptors on the pituitary gland as the full 44 amino acid structure[ii] [iii]. The first 29 amino acids in its protein structure were then isolated, which was then called GRF 1-29, but the problem with this derivative of GHRH was the fact that it was rapidly metabolized and cleared from the body by enzymes. Studies have reported that GRF 1-29’s half-life is less than 10 minutes and as little as 5 minutes[iv]. This was obviously not enough time to ensure a maximized and sustained release of HGH from the pituitary gland, as studies have demonstrated that the full potential of an HGH pulse from the pituitary requires at least 30 minutes as evidenced by the fact that much higher HGH levels (50 times greater) were observed 15 – 30 minutes into subcutaneous administration of GHRH analogues[v].
Therefore, the solution to this was to modify GRF 1-29 by replacing various amino acids in its structure with other amino acids that would provide a greater resistance to breakdown and cleavage by enzymes. There were many modified analogues developed, and Mod GRF 1-29 (CJC-1295 without DAC) was eventually selected for use, which demonstrated the most promising effects. Mod GRF 1-29 is a modification of GRF 1-29, specifically at amino acids #2, #8, #15, and #27. The result is an extended half-life to that of at least 30 minutes[vi] [vii].
Properties of Modified GRF 1-29 (CJC-1295 without DAC)
Mod GRF 1-29 acts upon receptors located in the anterior pituitary gland, and signals the pituitary gland to increase Human Growth Hormone production and cause a release of massive quantities of Human Growth Hormone in a pulsatile manner. The effects of Mod GRF 1-29 are very similar from what would be expected from synthetic HGH administration over the long term (see the Human Growth Hormone profile here), although the amount of time that the released human growth hormone will remain in circulation is of a far less amount of time than synthetic Human Growth Hormone does. Therefore, multiple applications of Mod GRF 1-29 is recommended throughout the day in order to simulate Human Growth Hormone levels that remain high on a constant basis. Mod GRF 1-29 (CJC-1295 without DAC) is commonly combined with a Ghrelin mimetic (also known as a GHRP – Growth Hormone Releasing Hexapeptide), such as GHRP-6, GHRP-2, Hexarelin, or Ipamorelin in order to initiate and amplify a greater pulse of HGH from the pituitary compared to Mod GRF 1-29 used solitarily on its own. The effects of a GHRH analogue (such as Mod GRF 1-29) and a Ghrelin mimetic (a GHRP such as GHRP-6 or Ipamorelin) are synergistic and amplify the release of HGH from the pi
[i] Human growth hormone-releasing factor (hGRF)1-29-albumin bioconjugates activate the GRF receptor on the anterior pituitary in rats: identification of CJC-1295 as a long-lasting GRF analog. Jetté L, Léger R, Thibaudeau K, Benquet C, Robitaille M, Pellerin I, Paradis V, van Wyk P, Pham K, Bridon DP. Endocrinology. 2005 Jul;146(7):3052-8. Epub 2005 Apr 7.
[ii] In vivo biological potency of rat and human growth hormone-releasing factor and fragments of human growth hormone-releasing factor. Wehrenberg WB, Ling N. (1983). Biochem Biophys Res Commun 115 (2): 525–530. doi:10.1016/S0006-291X(83)80176-4
[iii] Responses to analogues of growth hormone-releasing hormone in normal subjects, and in growth-hormone deficient children and young adults. Grossman A, Savage MO, Lytras N, et al. (1984). Clin Endocrinol (Oxf) 21 (3): 321–330.
[iv] Rapid enzymatic degradation of growth hormone-releasing hormone by plasma in vitro and in vivo to a biologically inactive product cleaved at the NH2 terminus. Frohman LA (1986). J Clin Invest 78 (4): 906–913. doi:10.1172/JCI112679.
[v] Potent trypsin-resistant hGH-RH analogues. Izdebski J, Witkowska E, Kunce D, Orłowska A, Baranowska B, Wolińska-Witort E. J Pept Sci. 2004 Aug;10(8):524-9.
[vi] New potent hGH-RH analogues with increased resistance to enzymatic degradation. Izdebski J (2002). JJ Pept Sci. 8 (7): 285–287.
[vii] Human Growth Hormone-Releasing Factor (hGRF)1–29-Albumin Bioconjugates Activate the GRF Receptor on the Anterior Pituitary in Rats: Identification of CJC-1295 as a Long-Lasting GRF Analog. Jetté L, Léger R, Thibaudeau K, Benquet C, Robitaille M, Pellerin I, Paradis V, van Wyk P, Pham K, Bridon DP (2005). Endocrinology 146 (7): 3052–8.