CJC-1295 is a long-acting GHRH analog whose DAC variant stretches a single dose across days.

What the CJC-1295 record establishes

CJC-1295 is a synthetic long-acting analog of growth-hormone-releasing hormone (GHRH), built on the hGRF(1-29) fragment with four protease-resistant amino-acid substitutions. The Drug Affinity Complex (DAC) variant adds a maleimide linker that covalently binds the peptide to circulating serum albumin, extending its plasma half-life toward that of albumin itself. In healthy adults, single subcutaneous doses of 30 or 60 µg/kg produced dose-dependent 2- to 10-fold increases in mean plasma growth hormone for six days or more, and 1.5- to 3-fold increases in IGF-1 for nine to eleven days; after multiple doses, IGF-1 stayed above baseline up to 28 days, and the estimated CJC-1295 half-life was 5.8 to 8.1 days ^[1].

That single-dose, multi-day signature is the whole reason CJC-1295 exists. Native GHRH is cleaved within minutes by dipeptidylpeptidase-IV (DPP-IV); the four substitutions block that cleavage, and albumin conjugation does the rest. The lead bioconjugate showed a 4-fold increase in growth-hormone area-under-the-curve over two hours versus unconjugated hGRF(1-29) in rats, with peptide detectable in plasma beyond 72 hours ^[2].

This site reads that record straight. Every figure on these pages maps to a published study, the long-acting DAC evidence is kept separate from the short-acting no-DAC form the forums routinely conflate with it, and the gaps — no validated human dose, no large efficacy or long-term safety trial, no regulatory approval — are marked rather than smoothed over. Start with the CJC-1295 DAC vs no-DAC distinction, or go straight to the GH/IGF-1 research.

CJC-1295 as a GHRH-Analog Peptide

CJC-1295 is a peptide, not a steroid and not a hormone in itself. As a CJC-1295 peptide it is a tetrasubstituted analog of hGRF(1-29) — the first 29 amino acids of human growth-hormone-releasing factor, the minimal sequence that retains full GH-releasing activity. The four substitutions (D-Ala at position 2, Gln at 8, Ala at 15, Leu at 27) stabilize the alpha-helix and block the deamidation, oxidation, and DPP-IV cleavage that clear the native molecule.

The DAC peptide carries a molecular weight near 3367.9 Da before albumin conjugation; the effective circulating species after conjugation is the much larger peptide-albumin complex, around 66 kDa. The CAS registry number consistently attributed to the DAC form is 863288-34-0. These identifiers describe a research chemical: CJC-1295 is not an approved drug, and what follows on this site is a reading of its literature, not a description of a product.

CJC-1295 in the GHRH-Analog Class

As a GHRH analog, CJC-1295 binds the growth-hormone-releasing hormone receptor (GHRHR) — a class B G-protein-coupled receptor on anterior-pituitary somatotrophs. Receptor binding activates Gs/cAMP/PKA signaling, driving synthesis and pulsatile release of growth hormone, which in turn raises hepatic IGF-1 through the JAK2/STAT5 pathway ^[1].

The class is broader than CJC-1295. A 2025 Nature Reviews Endocrinology review synthesized the pharmacology of GHRH and its synthetic analogues — the family that also includes sermorelin and the FDA-approved tesamorelin — describing receptor signaling and the rationale for long-acting analog design ^[12]. CJC-1295's particular contribution to that story is duration: it was the analog engineered to make one dose last days rather than minutes.

CJC-1295 and Ipamorelin: The Two-Receptor Rationale

CJC-1295 and ipamorelin are studied as a pairing because they act through different receptors. The phrase CJC-1295 ipamorelin, common in search, refers to this combination: CJC-1295 is a GHRH analog, working on the GHRH receptor; ipamorelin is a growth-hormone-releasing peptide (GHRP), a selective secretagogue acting on the ghrelin/GHS receptor. Because GHRH analogs and GHRPs engage distinct pathways, the two release more growth hormone together than either does alone — the mechanistic basis cited for combining a GHRH analog with a GHRP.

That synergy is a receptor-level rationale, not a validated regimen. CJC-1295 on its own raised growth hormone and IGF-1 in early human pharmacokinetic studies ^[1][3], but no controlled efficacy trial of the CJC-1295/ipamorelin combination in healthy adults exists. The pairing is described in detail on the CJC-1295 and ipamorelin page.

What is CJC-1295 ipamorelin?

A research pairing of a GHRH analog (CJC-1295) with a selective GH secretagogue (ipamorelin); the two act through distinct receptors, the mechanistic basis cited for combining a GHRH analog with a GHRP.

Read it by form and by evidence tier

The defining property of CJC-1295 is duration, and duration depends entirely on which form you mean. The DAC variant is the long-acting species — the multi-day half-life is its whole point. The no-DAC form, Modified GRF (1-29), keeps the four substitutions but lacks the albumin-binding moiety and is short-acting, cleared in the minutes-to-hours range. Marketing and forums conflate them constantly; the pharmacokinetics do not.

The evidence also splits by tier. Early human pharmacokinetic studies in healthy volunteers established the GH/IGF-1 kinetics ^[1][3]. Preclinical work in rats and GHRH-knockout mice established the bioconjugation mechanism and the once-daily growth normalization ^[2][4]. And a large body of claims circulating online — fixed-microgram protocols, anti-aging and muscle-building promises — sits in neither tier, because no controlled human outcome trial supports it. Those distinctions are marked throughout, including the CJC-1295 side effects page and the FDA and WADA status.