CJC-1295 is a long-acting GHRH analog tracked across its early human pharmacokinetic studies.

What the CJC-1295 record actually contains

CJC-1295 is a synthetic long-acting analog of growth-hormone-releasing hormone (GHRH). It is built on hGRF(1-29) — the first 29 amino acids of human GH-releasing factor — carrying four protease-resistant substitutions, and in its DAC form it binds covalently to circulating serum albumin to extend its plasma half-life toward several days ^[2]. That single structural idea defines the whole record below.

The human evidence is small but precise. In healthy adults, single subcutaneous doses of 30 or 60 ug/kg produced dose-dependent 2- to 10-fold increases in mean plasma GH for six days or more and 1.5- to 3-fold increases in IGF-1 for nine to eleven days; the estimated CJC-1295 half-life was 5.8-8.1 days ^[1]. In healthy men aged 20-40, a single dose of 60 or 90 ug/kg raised mean GH approximately 46% and IGF-1 approximately 45% one week later, while the natural pulsatile pattern of GH release was unchanged ^[3].

The preclinical foundation is older. The albumin-bioconjugate chemistry was screened in rats, where the lead conjugate — CJC-1295 — produced a 4-fold increase in GH area-under-the-curve over two hours versus unconjugated hGRF(1-29) and remained detectable in plasma beyond 72 hours ^[2]. In GHRH-knockout mice, 2 ug given once every 24 hours fully normalized body weight and length, while less frequent dosing was progressively less effective ^[4].

The rest of the story is regulatory and historical. The original long-acting DAC program at ConjuChem entered a Phase 2 trial in HIV-associated visceral obesity (NCT00267527) and was discontinued ^[7]. CJC-1295 is not approved for human use anywhere. This site is a digest of that published record — see the doses used in CJC-1295 research and the full reference list.

What is CJC-1295?

<a id="what-is"></a>

What is CJC-1295?

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 substitutions (D-Ala2, Gln8, Ala15, Leu27); the DAC variant adds covalent serum-albumin conjugation for a multi-day half-life ^[2]. Those substitutions block the enzyme dipeptidylpeptidase-IV that rapidly clears native GHRH, and the albumin handle is what makes the DAC form last days rather than minutes.

What Does CJC-1295 Do?

In studies, CJC-1295 binds the pituitary GHRH receptor and stimulates pulsatile growth-hormone release, which raises hepatic IGF-1; in healthy men a single dose raised mean GH about 46% and IGF-1 about 45% a week later ^[3]. The receptor it acts on is a class B G-protein-coupled receptor on the pituitary somatotrophs — the same target as the body's own GHRH.

CJC-1295 With DAC

The 'Drug Affinity Complex' version uses a maleimide linker that covalently binds the peptide to circulating serum albumin, extending its plasma half-life toward 5.8-8.1 days ^[1]. The effective circulating species is then the much larger peptide-albumin complex, which is why one injection keeps IGF-1 elevated for over a week.

CJC-1295 as a research peptide

<a id="research-peptide"></a>

CJC-1295 is a research peptide — a synthetic GHRH analog, not a steroid and not a blend. It is a single 29-residue peptide chain (molecular weight approximately 3367.9 Da for the DAC peptide before albumin conjugation; CAS 863288-34-0), and it works through the growth-hormone axis rather than the androgen receptor ^[2]. Marketing language that frames it as an anabolic agent collapses a precise pharmacological distinction.

The peptide is handled as a laboratory research chemical. Oral bioavailability is negligible, so every published study used injection ^[1]. There is no approved human formulation, and the controlled human dataset is limited to the early-phase pharmacokinetic studies summarized on this site.

CJC-1295 in the GHRH-analog class

<a id="ghrh-class"></a>

CJC-1295 in the GHRH-Analog Class

CJC-1295 belongs to the GHRH-analog class — synthetic molecules that mimic growth-hormone-releasing hormone at the pituitary GHRH receptor ^[2]. A 2025 Nature Reviews Endocrinology review synthesizes the pharmacology of GHRH and its synthetic analogues, the family that also includes sermorelin and tesamorelin, describing receptor signaling and the rationale for long-acting analog design ^[12]. The class shares a target; the members differ in how long they last and whether any regulator has approved them.

CJC-1295 and Ipamorelin: The Two-Receptor Rationale

GHRH analogs and growth-hormone-releasing peptides (GHRPs) act on distinct receptors and synergize, producing GH release greater than either alone ^[13]. CJC-1295 hits the GHRH receptor; ipamorelin is a selective GH secretagogue acting on the ghrelin/GHS receptor that releases GH with minimal effect on cortisol or prolactin ^[14]. That two-receptor model is the mechanistic basis for the commonly discussed pairing — though no controlled human efficacy trial of the specific combination in healthy adults exists. The mechanism is detailed in the CJC-1295 and ipamorelin section.