CJC-1295 (CJC1295, DAC:GRF, Drug Affinity Complex Growth Releasing Factor)

Overview

CJC-1295 is a synthetic analog of growth hormone-releasing hormone (GHRH), the hypothalamic peptide that stimulates the anterior pituitary gland to release growth hormone (GH). It was developed to address the short half-life of native GHRH (approximately 7 minutes in circulation) through the application of Drug Affinity Complex (DAC) technology — a modification that allows the peptide to bind to serum albumin, extending its half-life to 6–8 days.

Two forms circulate in research communities: CJC-1295 with DAC (extended half-life) and CJC-1295 without DAC (also called “Modified GRF 1-29” or “Mod GRF”), which behaves more like native GHRH with a half-life of approximately 30 minutes. The two are often used differently in research protocols.

CJC-1295 is almost always studied and used in combination with a GHRP (growth hormone-releasing peptide) such as Ipamorelin or GHRP-2, as the two classes of peptide act on complementary receptors (GHRH-R and GHSR, respectively) and produce synergistic GH release.

Mechanism of Action

GHRH Receptor Agonism: CJC-1295 binds to and activates the GHRH receptor (GHRH-R) on pituitary somatotrophs — the same receptor activated by endogenous GHRH. This stimulates synthesis and secretion of growth hormone in a pulsatile fashion that mimics physiological GH secretion (unlike exogenous GH administration, which suppresses endogenous pulsatility).

DAC Technology: The DAC modification involves a reactive maleimide group that forms a covalent bond with a cysteine residue on serum albumin. This “piggyback” binding dramatically extends circulating half-life and allows weekly (or twice-weekly) dosing rather than multiple daily injections.

GH Axis Effects: The resulting sustained increase in GH pulsation drives downstream production of IGF-1 (Insulin-like Growth Factor 1) from the liver — the primary mediator of GH’s anabolic and lipolytic effects.

Clinical Research & Evidence

Evidence Level: 🟠 EL3 — Limited human Phase I/II data; no Phase III trials

The primary published human study (Teichman 2006) demonstrated dose-dependent, sustained GH elevation with a favorable tolerability profile — but was a Phase I tolerability study, not a clinical efficacy trial. No Phase III data exists.

Research-Referenced Dosing Protocols

Extrapolated from animal models and Phase I human data. Not medical advice.

CJC-1295 with DAC:

• 1–2 mg subcutaneous, once or twice weekly
• Often combined with Ipamorelin 100–300 mcg at the time of injection for synergistic GH release

CJC-1295 without DAC (Mod GRF 1-29):

• 100 mcg subcutaneous, 1–3x daily
• Typically injected simultaneously with Ipamorelin 100–200 mcg
• Best timed 30–60 min before sleep to coincide with physiological GH pulse

Side Effects & Contraindications

Reported in human Phase I:

• Water retention / peripheral edema (common at initiation)
• Tingling extremities
• Headache
• Transient hypoglycemia (rare)
• Injection site reactions

Theoretical concerns:

• Growth promotion in existing malignancies (class concern for all GH-axis peptides)
• Acromegaly with chronic supraphysiological GH exposure
• IGF-1 elevation above normal range

Contraindications:

• Active malignancy or family history of GH-sensitive cancers
• Diabetic retinopathy
• Pregnancy

Legal & Regulatory Status

Research Citations

1. Teichman SL, et al. Prolonged stimulation of growth hormone (GH) and insulin-like growth factor I secretion by CJC-1295, a long-acting analog of GH-releasing hormone, in healthy adults. J Clin Endocrinol Metab. 2006.
2. Ionescu M, et al. On the pituitary and hypothalamic regulation of anterior pituitary growth hormone secretion. J Clin Endocrinol Metab. 2004.
3. Bowers CY. Unnatural growth hormone-releasing peptide begets natural ghrelin. J Clin Endocrinol Metab. 2001.