CJC-1295

Quick Facts

Introduction

CJC-1295 is a synthetic analogue of growth-hormone-releasing hormone (GHRH), the hypothalamic signal that tells the pituitary to secrete growth hormone. In research settings it is studied as a tool for probing the GH/IGF-1 axis, and it is frequently examined alongside Ipamorelin and Tesamorelin, with which it shares the broad theme of stimulating endogenous growth-hormone release.

A defining feature of the GHRH-analogue class is that these compounds work upstream of growth hormone rather than supplying it directly. Instead of introducing exogenous GH, they prompt the pituitary to release its own — which is why researchers describe the resulting secretion as preserving a more physiological, pulsatile pattern. CJC-1295's modifications were designed to extend the half-life of the native GHRH sequence, making it more practical to study.

This profile covers what CJC-1295 is, the important distinction between its DAC and non-DAC forms, its GHRH-receptor mechanism, the GH/IGF-1 research it appears in, and how it compares with related secretagogues such as Ipamorelin and Sermorelin. Related compounds are catalogued in the peptide database.

What is CJC-1295?

CJC-1295 is a modified GHRH(1-29) analogue — a synthetic version of the first 29 amino acids of growth-hormone-releasing hormone, the fragment that retains the native hormone's biological activity. Targeted amino-acid substitutions were introduced to slow enzymatic degradation, addressing the very short half-life that limits native GHRH as a research tool.

The compound exists in two commonly discussed forms. CJC-1295 with DAC (Drug Affinity Complex) adds a moiety that binds circulating albumin, dramatically extending its duration of action. CJC-1295 without DAC — often labeled Mod GRF (1-29) — lacks that addition and is shorter-acting. The two behave differently enough that researchers always specify which form a given study uses.

Molecular and structural characteristics

The backbone of CJC-1295 is the biologically active GHRH(1-29) fragment, stabilized by amino-acid substitutions at positions vulnerable to enzymatic cleavage. In the DAC form, a reactive linker allows the peptide to bond covalently to albumin in circulation, turning a short-lived signal into a long-lived one — the single biggest structural difference between the two forms.

Mechanism of action

CJC-1295 acts as a GHRH-receptor agonist on the somatotroph cells of the anterior pituitary. By binding the same receptor as native GHRH, it stimulates the synthesis and pulsatile release of growth hormone, which in turn drives hepatic production of insulin-like growth factor 1 (IGF-1) — the principal mediator of many of growth hormone's downstream effects.

Because it amplifies an existing signaling pathway rather than replacing it, CJC-1295 is studied as a way to raise GH output while retaining the pulsatility and feedback regulation of the natural axis. This is the conceptual contrast with administering growth hormone directly, which produces sustained, non-pulsatile elevations.

A central research theme is the synergy with ghrelin-mimetic secretagogues such as Ipamorelin. GHRH analogues and ghrelin-receptor agonists act through distinct receptors and complementary intracellular pathways, so combining them is studied for a larger, coordinated growth-hormone pulse than either produces alone. This complementary pairing is one of the most-discussed concepts in secretagogue research.

• GHRH-receptor agonism on pituitary somatotrophs.
• Stimulation of pulsatile growth-hormone release.
• Downstream elevation of IGF-1.
• Complementary action with ghrelin-mimetic secretagogues.

Growth-hormone axis research

The core research context for CJC-1295 is the GH/IGF-1 axis itself. Studies of the DAC form have reported sustained elevations in growth-hormone and IGF-1 concentrations over extended periods, illustrating how albumin binding converts a short hypothalamic signal into a prolonged stimulus. This durability is what made the DAC form attractive as a research tool relative to native GHRH.

Because growth hormone and IGF-1 influence body composition, metabolism, and tissue maintenance, CJC-1295 is examined in contexts overlapping with other GH-axis peptides. It sits in the same conceptual family as Tesamorelin, a GHRH analogue studied specifically for visceral-fat endpoints, and is contrasted with the gentler, more selective profile of Ipamorelin.

Comparison: CJC-1295 vs Ipamorelin vs Sermorelin

CJC-1295 is most often compared with Ipamorelin, a selective ghrelin-mimetic, and with Sermorelin, an earlier GHRH(1-29) analogue. All three influence growth-hormone release, but through different receptors and with different durations.

Researchers frequently study a GHRH analogue and a ghrelin-mimetic together because their pathways are complementary — for example CJC-1295 with Ipamorelin. Full entries for each are in the peptide database.

Half-life and pharmacokinetic considerations

Pharmacokinetics differ sharply between the two forms. With DAC, albumin binding extends the half-life into the range of days, supporting sustained GH/IGF-1 elevation; this is the property that distinguishes CJC-1295 from earlier GHRH analogues. Without DAC (Mod GRF 1-29), the half-life is on the order of minutes, producing a brief, pulsatile stimulus closer to native GHRH.

This difference is the single most important interpretive variable in CJC-1295 research. A finding from the long-acting DAC form cannot be assumed to apply to the short-acting form, and vice versa. Researchers therefore always note which form was used and treat half-life figures as form-specific.

Reconstitution and handling considerations

CJC-1295 is reconstituted with sterile or bacteriostatic water, added slowly down the vial wall and swirled gently rather than shaken. The reconstituted solution should be clear; cloudiness or particulates indicate it should be discarded.

Working concentration is selected so research volumes are convenient and reproducible. The reconstitution calculator and reconstitution guide describe the general method.

• Add diluent slowly; swirl gently rather than shaking.
• Confirm the solution is clear before use.
• Track which form (DAC vs no-DAC) each vial contains.
• Protect from light and excess warmth.

Storage considerations

Lyophilized CJC-1295 is most stable frozen at −20 °C, away from light and moisture. Once reconstituted, it is refrigerated at 2–8 °C and used within a limited window, avoiding repeated freeze–thaw cycles. Aliquoting reduces how often a given solution is cycled.

Research limitations

CJC-1295 is a research compound, and interpretation is complicated by the DAC/no-DAC distinction, which makes results form-dependent. While GHRH-analogue biology is comparatively well understood, much CJC-1295-specific data come from limited studies, and reported effects are dose-, form-, and design-dependent. It is described here strictly for research reference.

• Results depend on which form (DAC vs no-DAC) is studied.
• CJC-1295-specific human data are limited.
• Reported effects are dose- and design-dependent.
• It is not an approved therapy and is described solely for research reference.

Frequently Asked Questions

Related Research Profiles

References

1. Teichman SL, et al. Prolonged stimulation of growth hormone and IGF-I secretion by CJC-1295, a long-acting analog of GHRH, in healthy adults. J Clin Endocrinol Metab. 2006.Source
2. Sackmann-Sala L, et al. Growth hormone-releasing hormone and its analogues in health and disease. Nat Rev Endocrinol. 2014.Source