CJC-1295 No DAC

CJC-1295 no-DAC research peptide in Thailand

CJC-1295 no-DAC is a synthetic growth-hormone-releasing hormone (GHRH) analogue — the GHRH(1-29) active fragment carrying four amino-acid substitutions that resist enzymatic breakdown, which is why it is also called Modified GRF 1-29 (Mod GRF 1-29). It is studied as a short-acting pituitary GHRH-receptor agonist in growth-hormone axis, somatotroph signalling, and endocrine pharmacokinetics research.

This listing is for laboratory research use only. The published evidence for the no-DAC form is largely preclinical and early-phase; it is not a medicine, supplement, or performance product.

Quick facts

Product

CJC-1295 no-DAC (Modified GRF 1-29)

Parent hormone

Human GHRH(1-29), the active fragment of the 44-residue hormone

Substitutions

D-Ala², Gln⁸, Ala¹⁵, Leu²⁷ versus native GHRH(1-29)

Molecular weight

~3.4 kDa (29 residues, C-terminal amide)

Identifiers

CJC-1295 naming is inconsistent across catalogues; identifiers published for the DAC-bearing molecule must not be assumed to describe a no-DAC listing

Intended use

laboratory research use only

How CJC-1295 no-DAC works

GHRH is released from the hypothalamus and binds the GHRH receptor on pituitary somatotroph cells, a Gs-coupled receptor that activates adenylyl cyclase, raises intracellular cAMP, and drives growth-hormone synthesis and release. Native GHRH is a poor research tool because plasma destroys it almost immediately: Frohman and colleagues showed that plasma dipeptidylpeptidase-IV (DPP-IV) clips the first two residues to give the near-inactive GRH(3-44) fragment, with an in-vivo half-life for the intact peptide measured at 6.8 minutes (Frohman, J Clin Invest, 1986).

Modified GRF 1-29 is the engineering answer to that problem. The same group demonstrated that a D-amino-acid substitution at position 1 or 2 blocks DPP-IV hydrolysis outright (Frohman, J Clin Invest, 1989), which is precisely what the D-Ala² substitution does here; the Gln⁸, Ala¹⁵, and Leu²⁷ changes close off deamidation, backbone flexibility, and methionine-oxidation pathways respectively. The result is a peptide that survives long enough to be dosed reproducibly but still clears within minutes — so in study models it reinforces the pituitary's own pulsatile GH rhythm rather than holding GH continuously elevated.

The DAC distinction is the important one. The Drug Affinity Complex is a maleimide group that covalently tethers the peptide to circulating serum albumin. Adding it produces a fundamentally different pharmacokinetic molecule — a measured half-life of 5.8 to 8.1 days (Teichman, J Clin Endocrinol Metab, 2006) versus the minutes-range clearance of the no-DAC form. Same tetrasubstituted backbone, different research question entirely.

Key research findings

• The tetrasubstituted hGRF(1-29) backbone used in the no-DAC form was characterised alongside its albumin bioconjugates, which showed enhanced in-vitro stability against dipeptidylpeptidase-IV and were bioactive in a GH-secretion assay in cultured rat anterior pituitary cells (Jetté, Endocrinology, 2005).
• Plasma degradation of native GHRH proceeds through a single-step DPP-IV cleavage at the 2–3 bond, and D-amino-acid substitution at position 1 or 2 prevented that hydrolysis — the mechanistic basis for the D-Ala² modification (Frohman, J Clin Invest, 1989).
• In healthy adults, the DAC-bearing analogue raised mean plasma GH 2- to 10-fold for six days or more with an estimated half-life of 5.8–8.1 days, illustrating how large the DAC-versus-no-DAC pharmacokinetic gap is (Teichman, J Clin Endocrinol Metab, 2006).

Research applications

• Pulsatile growth-hormone release and somatotroph signalling models
• GHRH-receptor binding, cAMP response, and Gs-coupling assays
• Comparative pharmacokinetic work contrasting short-acting and DAC-bound GHRH analogues
• Peptide-stability and DPP-IV-resistance studies of substituted analogues
• Combined GHRH-analogue / GHRP secretagogue receptor-convergence models alongside ipamorelin
• Endocrine axis comparisons with other GHRH-family analogues such as tesamorelin

Dosing in the literature

Short-acting GHRH analogues are administered frequently in reported protocols precisely because they clear quickly — the opposite of the DAC-bound form, which appears in the literature at weekly or twice-weekly intervals. This is a summary of parameters as reported in research references, not administration guidance. To model concentrations for a defined protocol, use the CJC-1295 no-DAC peptide calculator.

Reconstitution & storage

Solvent

Bacteriostatic water — standard for lyophilised research peptides

Mixing

Add solvent down the vial wall and swirl gently until dissolved; do not shake

Storage

Refrigerated (2–8 °C) after reconstitution, in common laboratory practice

Use within

Roughly 3–4 weeks once reconstituted

Freeze / light

Keep lyophilised powder frozen or cold, sealed, and protected from light

These are common laboratory handling conventions for lyophilised peptides, not preparation instructions. In Thailand's heat and humidity, protect vials from ambient temperature swings during storage and courier handling, and minimise time spent at room temperature when handling.

Selected research

• 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 — J Clin Invest, 1986
• Dipeptidylpeptidase IV and trypsin-like enzymatic degradation of human growth hormone-releasing hormone in plasma — J Clin Invest, 1989
• 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
• 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 (the DAC-bearing form)
• 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
• Browse all indexed CJC-1295 and GHRH-analogue literature on PubMed

Related compounds

• Ipamorelin — a selective pentapeptide ghrelin-receptor (GHS-R1a) agonist. It is studied alongside GHRH analogues because the two act on different receptors on the same somatotroph cells, making the pair a standard model for receptor-convergence research.
• Tesamorelin — another stabilised GHRH(1-44) analogue, and the one member of this family with a substantial registered clinical trial record; useful as a comparator when the research question concerns GHRH-analogue evidence quality.
• Bacteriostatic water — the standard diluent used to reconstitute lyophilised research peptides.

See also: growth hormone secretagogues compared and more growth-hormone-axis compounds.

CJC-1295 no-DAC FAQ

Compliance note

CJC-1295 no-DAC is supplied for laboratory research use only. It is not for human or veterinary use, and it is not intended to diagnose, treat, cure, or prevent any disease. All findings referenced above are the results of specific published studies, not claims about this product.