Peptide · Research Monograph · Synthetic 30-amino-acid GHRH(1–29) analog with Drug Affinity Complex (DAC) albumin-binding modification

CJC-1295 DAC

Long-acting GHRH analog · albumin-bound depot

CJC-1295 DAC is a modified version of GHRH, the hormone that signals growth hormone release. It carries a chemical linker called a DAC that attaches permanently to albumin in the blood. That attachment is the whole point of the modification. Studies have measured how long it stays active: roughly six to eight days, compared to about thirty minutes for the version without the linker.

For laboratory research use only - not for human or animal use

Molecular data

Molecular formulaC152H252N44O42
Molecular weight3367.97 Da
SequenceTyr-D-Ala-Asp-Ala-Ile-Phe-Thr-Gln-Ser-Tyr-Arg-Lys-Val-Leu-Ala-Gln-Leu-Ser-Ala-Arg-Lys-Leu-Leu-Gln-Asp-Ile-Leu-Ser-Arg-Gln
Sequence length30 residues
CAS / identifier863288-34-0
Physical formLyophilized Powder
Available sizes5mg

How it works

GHRH-R Agonist

GHRH Receptor Activation

CJC-1295 DAC is a 30-amino acid analog of GHRH(1–29) with four substitutions that confer protease resistance. It binds and activates GHRH receptors on pituitary somatotrophs, acting on growth hormone synthesis and pulsatile release — the same signalling axis as endogenous GHRH, with a much longer duration.

  • Selective GHRH receptor agonism
  • GH synthesis measured in somatotrophs
  • Preserves pulsatile GH secretion pattern
DAC Technology

Albumin Binding — Half-Life Extension

The Drug Affinity Complex (DAC) is a maleimidopropionic acid group attached to Lys8 of the peptide. Once in circulation, it covalently bonds to Cys34 of serum albumin — eliminating DPP-IV cleavage and extending half-life from 7 minutes to 5.8–8.1 days. The albumin acts as a circulating depot, slowly releasing active peptide.

  • Covalent bond to serum albumin Cys34
  • Eliminates DPP-IV protease cleavage
  • 1,650× longer half-life vs native GHRH
IGF-1 Axis

Downstream IGF-1 Elevation

Sustained GH elevation is followed by hepatic insulin-like growth factor-1 (IGF-1) production. IGF-1 remains elevated 9–11 days from a single administration, with cumulative elevation recorded across repeated administrations.

  • IGF-1 elevated 1.5–3× above baseline
  • Sustained 9–11 days from a single trial dose
  • 28-day elevation on multi-dose protocol

What the research shows

GH / IGF-1 Axis

Sustained GH Elevation

A single administration was followed by GH 2–10× above baseline for 6+ days. Repeated-administration studies recorded IGF-1 above baseline for 28 days in adult study populations.

Pharmacokinetics

Albumin-Depot Mechanism

DAC covalently binds serum albumin Cys34, creating an endogenous depot. Half-life measured at 5.8–8.1 days in published pharmacokinetic characterisation.

Endocrinology

GHRH Axis Selectivity

Cortisol, thyroid hormones, and prolactin remain unaffected across all doses tested — confirming selective GHRH receptor agonism without hypothalamic–pituitary–adrenal axis activation.

Animal Models

Growth Normalization

In GHRH knockout mice, growth was restored toward wild-type, demonstrating in vivo GHRH receptor replacement activity in rodent models.

Specification

Also Known AsDAC:GRF, CJC-1295 with DAC
TypeSynthetic GHRH analog with Drug Affinity Complex
CAS Number863288-34-0
Molecular Weight3,647.1 g/mol
Amino Acids30 (GHRH 1–29 analog)
DAC ModificationMaleimidopropionic acid on Lys8 → covalent albumin Cys34 binding
Plasma Half-Life5.8–8.1 days (albumin-bound)
FormLyophilized powder
Purity≥99% (HPLC verified)
TestingThird-party HPLC, Mass Spec, Endotoxin
Storage-20°C for up to 24 months
SolubilityWater-soluble
COAIncluded with every order
Strength5mg
Molecular FormulaC152H252N44O42
AppearanceWhite to off-white powder

Frequently asked questions

What is CJC-1295 DAC and how does the DAC modification work?

CJC-1295 DAC (also called DAC:GRF) is a 30-amino acid synthetic analog of growth hormone-releasing hormone (GHRH) with a Drug Affinity Complex (DAC) modification — a maleimidopropionic acid group at Lys8. Once in circulation, this group covalently bonds to Cys34 of serum albumin. Albumin acts as a circulating depot, slowly releasing active peptide and extending the half-life from ~7 minutes (native GHRH) to 5.8–8.1 days.

What is known about CJC-1295 DAC's pharmacokinetics?

Pharmacokinetic characterisation in adult study populations reported GH elevated 2–10× above baseline for 6+ days and IGF-1 elevated 1.5–3× for 9–11 days. Repeated-administration protocols maintained IGF-1 above baseline for up to 28 days with a cumulative effect. No serious adverse events were reported.

How is CJC-1295 DAC different from CJC-1295 without DAC (Modified GRF 1-29)?

The sole structural difference is the DAC modification. CJC-1295 without DAC (Modified GRF 1-29, "Mod GRF") has a half-life of approximately 20–30 minutes, so a sustained GH signal requires frequent administration in research settings. CJC-1295 DAC's albumin binding extends the half-life to ~8 days - a markedly longer interval, while preserving the same GHRH receptor selectivity.

Does CJC-1295 DAC affect cortisol or other stress hormones?

No. CJC-1295 DAC acts selectively on the GHRH receptor on pituitary somatotrophs. Published characterisation describes cortisol, thyroid hormones (T3, T4, TSH) and prolactin as unaffected across the range examined. This selectivity distinguishes it from non-selective GH secretagogues such as GHRP-6 and hexarelin, which elevate cortisol and prolactin.

Is CJC-1295 DAC FDA-approved?

No. CJC-1295 DAC was developed by ConjuChem Biotechnologies (Canada), and development was never pursued after the company dissolved. It has never received FDA approval and is classified as a research compound. It is sold for in vitro research purposes only and is not intended for human therapeutic use.

How should CJC-1295 DAC be stored?

Lyophilized (powder) form should be stored at -20°C for up to 24 months. Avoid repeated freeze-thaw cycles and protect from light and heat. The DAC modification does not significantly affect peptide stability in lyophilized form.

For laboratory research use only. Not a drug, supplement, or medical product; not for human or animal use. All findings referenced are from published preclinical/laboratory research.