CJC 1295 + DAC

A GHRH analog of the long-acting kind; the DAC is an albumin-binding modification, not a second peptide

Overview

CJC-1295 with DAC is a long-acting synthetic analog of growth hormone-releasing hormone (GHRH). Chemically, "DAC" is no additional peptide bolted onto CJC-1295; it abbreviates Drug Affinity Complex, a modification designed to permit covalent binding to albumin in the blood and to prolong the peptide's exposure time [1,4]. "CJC + DAC" is therefore an imprecise way of writing CJC-1295 DAC. CJC-1295 DAC also has to be kept apart from shorter compounds that sometimes go by "CJC-1295 without DAC" or Mod GRF(1-29), which are not equivalent in structure, half-life or research data. CJC-1295 DAC is not an FDA-approved drug. Human studies on it come mainly from the early 2000s and examined the effect on GH and IGF-1 in healthy adults rather than long-term clinical outcomes [1-3].

How It Works Biologically

CJC-1295 DAC binds the GHRH receptor in the pituitary gland and stimulates release of growth hormone from somatotroph cells. A rise in GH can carry IGF-1 upward, mainly by way of the liver but in other tissues as well [1]. Within the DAC sits a chemical group that allows a bond to form with endogenous albumin, and binding to albumin slows rapid clearance and prolongs the duration of activity relative to natural GHRH or short analogs [1,4]. Lengthening the exposure changes the biology of the system: natural GHRH acts in short, pulsatile patterns, whereas CJC-1295 DAC delivers more sustained stimulation. One human study showed a degree of pulsatility in GH secretion surviving even prolonged exposure, though the profile is not identical to the normal physiological state [2].

What the Studies Report

In healthy adults, a clinical study published in 2006 found that CJC-1295 produced a sustained, exposure-dependent rise in GH and IGF-1 levels, with an effect reaching beyond the short window of natural GHRH [1]. A further study from the same period showed that GH pulses did not vanish altogether despite continuous stimulation [2]. A later study looked at changes in the serum protein profile following activation of the GH/IGF-1 axis by CJC-1295, demonstrating that the effect does not stop at the measurement of two hormones alone [3]. The human studies are small, however, and prove no clinical benefit in areas such as body composition, recovery, sleep, "anti-aging" or performance. A rise in GH and IGF-1 evidences pharmacological activity — not a desirable health outcome.

Prolonged Exposure vs. Physiological Secretion

Sleep, nutrition, physical activity, age, somatostatin and GHRH all influence the GH system, which operates in a pulsatile manner. The question is consequently not only whether CJC-1295 DAC raises GH, but how prolonged exposure alters the coordination among these pathways. The study showing preservation of a certain pulsatility is important, yet it does not prove the pattern stays entirely physiological [2]. Prolonged stimulation can shift the baseline level, the feedback response and the duration of exposure to IGF-1. Against short GHRH analogs, in which exposure runs briefer, this difference is especially significant. Data on CJC-1295 DAC should therefore not be blended with data on short peptides sold under the same commercial name.

Safety & Regulation

Several forms of CJC-1295 and CJC-1295 DAC went through FDA review in the context of the bulk drug substances list for compounding, and the agency proposed not to include them on the 503A list. Limited clinical data, ambiguity about the exact form tested in some studies, and preclinical signals warranting caution were all noted in the evaluation documents [4,5]. The FDA further notes serious adverse events reported with CJC-1295, increased heart rate and a systemic vasodilatory response among them, plus concerns around immunogenicity, peptide-related impurities and characterization of the active substance [5]. A detailed evaluation document on CJC-1295 DAC noted an absence of long-term carcinogenicity studies, and that chronic stimulation of the GHRH/GH axis raises theoretical questions about pituitary hyperplasia and growth pathways [4]. None of this proves specific harm in humans, but it is why short-term hormone data do not suffice for a safety assessment.

GH & IGF-1 Markers vs. Clinical Benefit

GH and IGF-1 serve as key biomarkers without being clinical outcomes in themselves. A rise in them may come accompanied by effects on glucose, fluid retention, connective tissue and growth systems, so a net improvement in health cannot be inferred from a rise in a hormonal marker. Establishing a genuine clinical benefit would take studies measuring function, body composition by valid methods, glucose metabolism, sleep quality, quality of life, cardiac events and long-term safety. Studies of that kind do not exist on a scale that would let CJC-1295 DAC be defined as an established treatment for the general population.

Summary

CJC-1295 DAC is a long-acting GHRH analog in which the DAC is a chemical modification for albumin binding rather than a separate peptide [1,4]. Small human studies described a prolonged increase in GH and IGF-1, yet no broad clinical basis supports long-term benefit, and the FDA has raised concerns about safety, quality and missing data [4,5]. The substance is intended for laboratory research use only.

Selected Research Sources

1. Teichman S.L. et al. Prolonged stimulation of growth hormone and insulin-like growth factor I secretion by CJC-1295, a long-acting analog of growth hormone-releasing hormone, in healthy adults. Journal of Clinical Endocrinology & Metabolism, 2006. PMID: 16352683
2. Ionescu M.I., Frohman L.A. Pulsatile growth hormone secretion persists during continuous stimulation by CJC-1295, a long-acting GHRH analog. Journal of Clinical Endocrinology & Metabolism, 2006. PMID: 17018654
3. Sackmann-Sala L. et al. Activation of the GH/IGF-1 axis by CJC-1295 results in serum protein profile changes in normal adult subjects. Growth Hormone & IGF Research, 2009. PMID: 19386527
4. U.S. Food and Drug Administration. Pharmacy Compounding Advisory Committee briefing document on CJC-1295 and CJC-1295 DAC-related bulk drug substances, December 2024.
5. U.S. Food and Drug Administration. Certain Bulk Drug Substances for Use in Compounding that May Present Significant Safety Risks. Entry for CJC-1295.