CJC-1295 (NO DAC) 5MG

CJC-1295 without DAC, also sold as modified GRF(1-29), is the 29-residue N-terminal fragment of growth hormone-releasing hormone with four amino acid substitutions and an amidated C-terminus. It carries no drug affinity complex, so it has no group that can bind albumin. This listing is the 5 mg vial of freeze-dried powder, the main fill; a 10 mg vial and a blend with ipamorelin are also sold. Most published CJC-1295 data describe the DAC form, which is a different molecule.

Specifications

Fills in this range

CJC-1295 (no DAC) is sold in 2 fills. The compound and the testing are the same in every fill; only the amount in the vial changes.

Which CJC-1295 this vial contains

Two different molecules are sold under the CJC-1295 name, and this vial holds the one without DAC. The certificate gives its sequence as H-Y-[D-Ala]-DAIFTQSYRKVLAQLSARKLLQDILSR-NH₂: 29 residues with D-alanine at position 2, glutamine at 8, alanine at 15 and leucine at 27, a C-terminal amide and a theoretical mass of 3367.9 Da. The DAC form described by Jetté and colleagues keeps the same four-substitution backbone and adds a C-terminal lysine whose side chain carries a maleimidopropionamide group¹. That group is what bonds to albumin. It also makes the DAC molecule heavier, so the LC-MS identity result on the certificate tells the two apart at once.

The D-alanine sits at the bond that dipeptidyl peptidase IV attacks: the enzyme removes an Xaa-Pro or Xaa-Ala dipeptide from the N-terminus of its substrates, and GHRH is one of them². The certificate’s molecular formula contains no sulfur, so the chain has no methionine or cysteine. From the stated mass, 5 mg is about 1.5 µmol, slightly less once the certificate’s water content is allowed for.

What the research covers

The enzyme problem behind GHRH analogues

Work on GHRH analogues followed quickly on the hormone’s discovery. A 1986 review counted nearly 500 papers in little more than three years after the structure was determined, and noted that GHRH and its analogues were already in use as diagnostic and therapeutic agents³. One obstacle to using the native peptide is clearance. Dipeptidyl peptidase IV cuts a dipeptide from the N-terminus of many regulatory peptides, including GHRH, GLP-1 and neuropeptide Y, and this small truncation can inactivate a peptide entirely or at particular receptor subtypes².

How CJC-1295 was built

Jetté and colleagues set out to lengthen the plasma half-life of GRF by giving it a reactive group that bonds, in the body, to the free thiol on cysteine 34 of serum albumin¹. They made three maleimido derivatives of human GRF(1-29). Conjugated to human serum albumin outside the body, all three were more stable against DPP IV in vitro and remained active in a growth hormone secretion assay using cultured rat pituitary cells¹. The title result was that these conjugates activate the GRF receptor on the anterior pituitary in rats¹. The compound they selected, CJC-1295, combined a tetrasubstituted GRF(1-29) with an extra lysine bearing the maleimide group at the C-terminus¹. In rats it produced a fourfold larger growth hormone area under the curve over two hours than GRF(1-29), remained in plasma beyond 72 hours and showed up on the albumin band of a Western blot from 15 minutes to more than 24 hours¹. The peptide in this vial is the substituted backbone without that lysine, and the abstract reports no results for the backbone tested on its own¹.

What the human data describe

The clinical CJC-1295 studies used the albumin-binding form. In two randomised, placebo-controlled, double-blind trials in healthy adults aged 21 to 61, lasting 28 and 49 days, its estimated half-life was 5.8 to 8.1 days, and a single treatment raised mean growth hormone two- to tenfold for six days or more and IGF-I 1.5- to threefold for 9 to 11 days⁴. A second study sampled growth hormone every 20 minutes overnight in healthy men a week after one treatment with the DAC form: pulse frequency and size were unchanged while trough levels rose 7.5-fold⁵. Those numbers belong to the DAC molecule. Without the maleimide there is no albumin binding, so they say nothing direct about how long the peptide in this vial persists.

What is not established

None of the papers cited here measured the half-life, potency or effects of CJC-1295 without DAC as a molecule in its own right, in animals or in people. Half-life figures quoted for it elsewhere do not come from these references. None of the work used PrymaLab material. The CJC-1295 and ipamorelin guide sets out the DAC and no-DAC distinction in more detail.

How each lot is tested

Every lot is tested in PrymaLab’s own laboratory in Ashland, Kentucky before release: RP-HPLC for purity, LC-MS for identity, Karl Fischer titration for water, LAL for endotoxin and USP <71> for sterility. The results for the lot now shipping are in the certificate panel on this page, and the certificate number, key and QR code can be checked on the verify page. These are in-house results from PrymaLab Analytical, not an independent test, and the lab is not accredited to ISO 17025. The third-party testing guarantee on this page still applies: if any independent laboratory finds the wrong compound, or less than the stated purity or amount, the order is refunded and the cost of the test is reimbursed.

Frequently asked questions

References

1. Jetté L, Léger R, Thibaudeau K, et al. 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. Endocrinology. 2005;146(7):3052-8. DOI · PubMed
2. Mentlein R. Dipeptidyl-peptidase IV (CD26)–role in the inactivation of regulatory peptides. Regul Pept. 1999;85(1):9-24. DOI · PubMed
3. Frohman LA, Jansson JO. Growth hormone-releasing hormone. Endocr Rev. 1986;7(3):223-53. DOI · PubMed
4. Teichman SL, Neale A, Lawrence B, et al. Prolonged stimulation of growth hormone (GH) and insulin-like growth factor I secretion by CJC-1295, a long-acting analog of GH-releasing hormone, in healthy adults. J Clin Endocrinol Metab. 2006;91(3):799-805. DOI · PubMed
5. Ionescu M, Frohman LA. Pulsatile secretion of growth hormone (GH) persists during continuous stimulation by CJC-1295, a long-acting GH-releasing hormone analog. J Clin Endocrinol Metab. 2006;91(12):4792-7. DOI · PubMed