CJC-1295 W/O DAC (Mod GRF 1-29) 2mg

CJC-1295 W/O DAC (Mod GRF 1-29) 2mg — Research Overview

CJC-1295 Without DAC — often called Modified GRF 1-29 or simply Mod GRF 1-29 — is a modified GHRH analogue. It’s based on the first 29 amino acids of endogenous GHRH, which is the same core fragment found in sermorelin. However, this version features four strategic amino acid substitutions designed to boost resistance to enzymatic breakdown and improve how it binds to receptors. These specific swaps at positions 2 (Ala → D-Ala), 8 (Asn → Gln), 15 (Gly → Ala), and 27 (Met → Leu) protect the peptide from dipeptidyl peptidase-4 (DPP-4) cleavage and oxidative damage without losing its affinity for the GHRH receptor. What you get is a short-acting GHRH analogue with a plasma half-life of around 30 minutes. This creates a sharp GH pulse that mimics natural, physiological pulsatile release much more closely than the longer-acting versions.

Mechanism of Action

Just like other GHRH analogues, CJC-1295 W/O DAC targets the GHRH receptors found on anterior pituitary somatotrophs. Once these receptors are activated, they boost intracellular cAMP levels via Gs/adenylyl cyclase coupling. This process triggers protein kinase A and specific transcription factors that ramp up GH gene expression and drive the release of GH from vesicles. Thanks to its four-substitution modification, this peptide stays active in the bloodstream longer than native GHRH or unmodified sermorelin. Crucially, it still respects natural GH pulsatility. Because it’s cleared from the system before the next pulse begins, you see both the expected rise and the return to baseline.

This pharmacokinetic profile is a far cry from CJC-1295 W/ DAC 2mg. That version uses a drug affinity complex (DAC) to bind covalently to serum albumin, which stretches the half-life out and creates steady GH elevation instead of distinct pulses. Because of this difference, researchers looking at how GH pulse amplitude compares to trough depth often test these two forms side-by-side in animal models.

Research Context

Researchers often study CJC-1295 W/O DAC alongside GH secretagogues like Ipamorelin 2mg. There is a clear mechanistic reason for this: GHRH analogues boost the amplitude of GH pulses by making somatotrophs more responsive, whereas secretagogues like ipamorelin and GHRP-6 trigger the pulse itself via GHS-R1a. In animal models, combining these agents consistently results in larger GH pulses than using either one on its own. This suggests a synergistic effect across complementary receptor pathways. For those looking into these interactions, the CJC-1295 / Ipamorelin Blend offers a practical way to co-administer them. This product is for research purposes only and is not intended for human administration; it should only be handled by qualified investigators.

Researchers often use CJC-1295 W/O DAC as a benchmark GHRH analogue in pharmacokinetic studies, mainly because its half-life and receptor selectivity are so well-documented. By comparing it directly with Sermorelin 2mg and Tesamorelin 2mg under the same experimental conditions, research teams can isolate exactly how each modification affects receptor binding, resistance to degradation, and the total magnitude of GH release.

Laboratory Handling

CJC-1295 W/O DAC comes as a lyophilised powder, which researchers must reconstitute using sterile bacteriostatic water. For short-term use, solutions should be kept at 4°C, but moved to −20°C if the investigator is planning longer-term storage. Because of its modified amino acid sequence, it is slightly more stable than native GHRH, though labs should still stick to standard peptide storage protocols. It is recommended that research teams run HPLC purity verification before starting any dose-response experiments.

This product is for research purposes only. It isn’t intended for clinical use or human administration.

References

• Jetté L, et al. hGRF1-29-albumin bioconjugates activate the GRF receptor on the anterior pituitary in rats. 2005;146(7):3052–3058.
• Walker RF. Sermorelin: a better approach to management of adult-onset growth hormone insufficiency? Clin Interv Aging. 2006;1(4):307–308.
• Sigalos JT, Pastuszak AW. The safety and efficacy of growth hormone secretagogues. Sex Med Rev. 2018;6(1):45–53.
• Teichman SL, et al. Prolonged stimulation of growth hormone (GH) and insulin-like growth factor I secretion by CJC-1295. J Clin Endocrinol Metab. 2006;91(3):799–805.

Comparative Notes

Naming CJC-1295 variants has caused a fair bit of confusion in the literature. Some researchers use “CJC-1295” for the DAC-containing version and “Mod GRF 1-29” for the W/O DAC version, so it’s vital to verify which formulation a study is actually using before referencing or replicating it. The practical distinction—short-acting pulsatile GH stimulation versus prolonged, sustained GH/IGF-1 elevation—is biologically significant. It makes the two compounds suitable for very different experimental designs, even though they share the same core GHRH analogue scaffold.

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