CJC-1295 DAC research centers on a modified growth-hormone-releasing hormone (GHRH) analog engineered for an unusually long circulating half-life. The "DAC" — Drug Affinity Complex — is a small maleimidopropionic acid group that covalently tethers the peptide to serum albumin after administration, transforming a molecule that would normally clear in minutes into one that persists in plasma for days. For laboratories studying the GH/IGF-1 axis, this pharmacokinetic property is precisely what makes CJC-1295 with DAC a distinctive research tool: it allows investigators to examine sustained GHRH-receptor engagement in preclinical models without the rapid degradation that limits native GHRH.
Research Use Only Disclaimer: CJC-1295 with DAC is supplied strictly for laboratory and in-vitro research use only. It is not for human or veterinary use, is not a dietary supplement, and has not been evaluated or approved by the FDA. It is not intended to diagnose, treat, cure, or prevent any disease. Nothing in this article constitutes medical guidance or a dosing protocol for any person or animal. All handling described refers to laboratory preparation of research materials by qualified personnel.
What CJC-1295 with DAC Is
Native GHRH is a 44-amino-acid hypothalamic peptide; its biological activity resides largely in the first 29 residues (GHRH 1-29, also called sermorelin). CJC-1295 is built on this 1-29 fragment with four strategic amino acid substitutions (positions 2, 8, 15, and 27) that resist enzymatic degradation — chiefly by dipeptidyl peptidase-4 (DPP-4) — and a lysine-linked DAC moiety at the C-terminus. In research literature the base tetra-substituted peptide is sometimes referenced as "DAC:GRF."
The core mechanism mirrors endogenous GHRH: the peptide binds the GHRH receptor (GHRHR), a class B G-protein-coupled receptor on anterior pituitary somatotrophs. Receptor activation raises intracellular cyclic AMP, drives protein kinase A signaling, and promotes pulsatile synthesis and release of growth hormone. Because CJC-1295 acts upstream at the pituitary, models typically observe that it amplifies GH pulse amplitude while the hypothalamic-somatostatin brake still shapes pulse timing — a point of ongoing interest in GH-axis research.
The DAC Half-Life Extension: Why It Matters for Research Design
The defining research feature of this analog is its pharmacokinetics. Unmodified GHRH and GHRH 1-29 clear within a few minutes. The tetra-substitution alone extends stability by blocking DPP-4 cleavage. The DAC adds a second, larger effect: upon reconstitution and entry into a biological matrix, the maleimide group forms a stable thioether bond with cysteine-34 of circulating albumin. Because albumin itself circulates for roughly three weeks, the bound peptide is shielded from renal filtration and enzymatic attack, and published pharmacokinetic work in animal and early human research has reported terminal half-lives on the order of several days.
For a research model, this creates a fundamentally different exposure profile from short-acting secretagogues:
| Property | GHRH 1-29 (sermorelin) | CJC-1295 (no DAC / "mod GRF 1-29") | CJC-1295 with DAC |
|---|---|---|---|
| Circulating half-life | ~minutes | ~30 min (DPP-4 resistant) | ~days (albumin-bound) |
| Primary stabilizing feature | None | 4 amino-acid substitutions | Substitutions + DAC albumin conjugation |
| GH release pattern in models | Sharp, brief pulse | Discrete pulse | Elevated GH/IGF-1 "bleed" over days |
| Typical research question | Acute GHRHR response | Pulse pharmacology | Sustained axis exposure |
The trade-off researchers weigh is that the extended, non-pulsatile elevation produced by the DAC form departs from the body's natural pulsatile GH rhythm. This makes it valuable for studying chronic GHRHR stimulation and steady IGF-1 elevation, but less suitable for models designed to preserve physiological pulsatility — a contrast explored in our CJC-1295 with vs without DAC comparison.
Position in the GH Secretagogue Landscape
CJC-1295 with DAC sits within the broader family of growth hormone secretagogue peptides, and its research relevance is clearest when contrasted with adjacent tools:
- GHRH analogs vs ghrelin mimetics. CJC-1295 acts at the GHRH receptor, whereas growth-hormone secretagogue-receptor (GHS-R1a) agonists such as those covered in our Ipamorelin research guide act through a separate ghrelin-mimetic pathway. Because the two receptors are complementary, co-stimulation is a frequent theme in synergy research models.
- CJC-1295 vs tesamorelin. Tesamorelin is another stabilized GHRH analog but without DAC conjugation, giving it a shorter, more pulse-like profile — the mechanistic differences are detailed in our tesamorelin vs CJC-1295 comparison.
- Upstream axis context. Investigators new to this pathway may want the full receptor-and-feedback picture in our GHRH and growth hormone axis mechanism guide.
What Research Models Have Examined
Studies have examined CJC-1295 with DAC primarily as a probe of sustained GHRH-receptor signaling. Reported and investigated areas in preclinical and early-phase literature include:
- GH and IGF-1 kinetics. Research suggests a single administration in animal and early human models can raise mean GH and IGF-1 concentrations for an extended window, allowing study of dose-versus-exposure relationships without frequent dosing.
- Somatotroph responsiveness. In-vitro pituitary and cell-based models are used to characterize GHRHR binding affinity, cAMP response, and receptor desensitization under prolonged agonist exposure.
- Axis feedback interactions. Because IGF-1 and somatostatin feed back on the axis, models examine how continuous GHRHR drive interacts with these brakes.
- Combination pharmacology. Research models frequently pair a GHRH analog with a GHS-R agonist to study additive or synergistic GH release.
These are mechanistic and pharmacokinetic research questions. No therapeutic conclusion or human-use recommendation should be drawn from them.
Laboratory Handling and Reconstitution
CJC-1295 with DAC is supplied as a lyophilized powder for research preparation. General laboratory handling considerations include:
- Storage. Store lyophilized peptide at -20°C, protected from light and moisture. The intact powder is stable long-term when kept frozen and desiccated.
- Reconstitution. Bacteriostatic or sterile water is typically used to dissolve the powder; add diluent slowly down the vial wall rather than directly onto the pellet to preserve peptide integrity. Because the DAC's maleimide group is designed to react with albumin cysteine, avoid reducing agents or thiol-containing buffers in the working preparation.
- Post-reconstitution. Keep reconstituted solution refrigerated at 2-8°C and use within a limited window; avoid repeated freeze-thaw cycles. Full step-by-step laboratory instructions are in our CJC-1295 reconstitution lab prep guide.
- Verification. Confirm identity and purity against the batch certificate of analysis before use in any assay.
Quality and Sourcing for Research
Reproducible GH-axis research depends on well-characterized material. Our CJC-1295 with DAC 5mg is supplied at ≥99% purity, third-party COA-tested by lot, and shipped same-day within the USA. Each vial ships with documentation so investigators can verify identity, purity, and mass before incorporating it into an experimental protocol.
Reminder: this material is for laboratory research use only. It is not a drug, supplement, or therapeutic product, has not been evaluated by the FDA, and is not intended to diagnose, treat, cure, or prevent any disease in humans or animals.