CJC-1295 with DAC is a 30-amino-acid analogue of growth hormone-releasing hormone (GHRH) fitted with a Drug Affinity Complex, a reactive maleimide group that covalently binds the peptide to circulating albumin after injection. The modification extends the half-life from minutes to days, which is why the compound produced week-long elevations of growth hormone and IGF-1 in the only human trials ever run on it. This profile covers the chemistry, the two 2006 clinical papers that constitute the entire human evidence base, why the developer abandoned it, and what the 42 suppliers on Peptides.SO charge for it.
> Research use only. CJC-1295 DAC sold through the suppliers listed here is a laboratory reagent for in-vitro and preclinical investigation. It has never been approved as a drug anywhere, and nothing on this page is a protocol for human or animal administration.
What CJC-1295 DAC is
Native GHRH is a 44-residue hypothalamic peptide; its first 29 residues (GRF 1-29) carry full activity. CJC-1295 starts from GRF 1-29 with four amino-acid substitutions that protect it from the enzymes that normally degrade GHRH within minutes (a D-Ala at position 2 against dipeptidyl peptidase-4, Gln at 8, Ala at 15 and Leu at 27 against other cleavage and deamidation). Without the DAC, that tetra-substituted peptide is what suppliers sell as "CJC-1295 no DAC" or Mod GRF 1-29; the difference is covered in the DAC vs no-DAC comparison and the Mod GRF 1-29 vs CJC-1295 article.
The DAC is a lysine linker carrying a maleimidopropionic acid group at the C-terminus. Maleimides react selectively with free thiols, and the dominant free thiol in plasma is cysteine-34 of serum albumin. Within minutes of subcutaneous injection the peptide is covalently attached to albumin and inherits albumin's circulation time. ConjuChem, the Montreal company that developed the technology, applied the same chemistry to insulin, GLP-1 and exendin analogues.
Mechanism of action
GHRH receptor activation
CJC-1295 acts at the GHRH receptor on pituitary somatotrophs, a family B G-protein-coupled receptor that signals through Gs, adenylyl cyclase and cAMP to drive both growth hormone synthesis and release. The review Regulation of the pituitary somatotroph cell by GHRH and its receptor (PMID 11036940) describes how GHRH acting through this receptor also stimulates somatotroph proliferation during development, which is why GHRH-receptor mutations produce dwarfism and why sustained GHRH stimulation has been examined for trophic effects on the gland.
What the human pharmacology showed
Two papers in the Journal of Clinical Endocrinology and Metabolism, both from 2006, are the whole clinical literature.
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 (PMID 16352683) reports two randomised, placebo-controlled, double-blind ascending-dose studies of 28 and 49 days in healthy adults aged 21 to 61. After a single subcutaneous injection, mean plasma GH rose 2- to 10-fold for six days or more and mean IGF-1 rose 1.5- to 3-fold for 9 to 11 days, both dose-dependently. The estimated half-life of the conjugate was 5.8 to 8.1 days. After repeated doses, IGF-1 remained above baseline for up to 28 days, with evidence of accumulation. No serious adverse reactions were reported, and the authors described the compound as "safe and relatively well tolerated" at the two lower dose levels.
Pulsatile secretion of growth hormone (GH) persists during continuous stimulation by CJC-1295, a long-acting GH-releasing hormone analog (PMID 17018654) answered the obvious physiological question: does continuous GHRH-receptor occupancy flatten the pulsatile GH rhythm that mediates many of the hormone's effects? Overnight 20-minute sampling in healthy men one week after injection showed that pulse frequency and amplitude were unchanged. Basal GH between pulses rose 7.5-fold, driving a 46% rise in mean GH and a 45% rise in IGF-1. The IGF-1 increase did not correlate with any pulse parameter, which the authors read as trough GH being the main driver of IGF-1 output under continuous GHRH stimulation.
Those two findings together describe the compound's pharmacology: pulsatility preserved, baseline elevated, IGF-1 up for weeks after one injection.
Why development stopped
ConjuChem's programme was aimed at HIV-associated lipodystrophy and growth hormone deficiency. ConjuChem halted it in the mid-2000s (contemporary reports cite a participant death in a lipodystrophy study that was not attributed to the drug), the programme never restarted, the company itself later ceased operations, and the compound has no completed efficacy trial in any indication. The same indication was subsequently taken to approval by a different GHRH analogue, tesamorelin, whose pooled phase 3 data appear in Effects of tesamorelin (TH9507), a growth hormone-releasing factor analog, in human immunodeficiency virus-infected patients with excess abdominal fat (PMID 20554713): a 17.5% reduction in visceral adipose tissue maintained at 52 weeks, with no clinically meaningful change in glucose parameters. Tesamorelin's success is often cited as indirect support for CJC-1295, but it is a daily-injected, non-albumin-bound molecule with a different exposure profile, and the extrapolation is speculative.
The compound today: doping control and self-administration
Because it never became a drug, the recent literature on CJC-1295 comes from two directions: anti-doping laboratories and clinicians who encounter people using it.
Analysis of growth hormone releasing hormone and its analogs in urine using nano liquid chromatography coupled with quadrupole/orbitrap mass spectrometry (PMID 41138283) describes a WADA-compliant method for detecting sermorelin, tesamorelin and CJC-1295 in urine, and notes the analytical difficulty posed by "inherent in vivo instability, rapid renal clearance, and low urinary concentrations". GHRH analogues are prohibited in sport under the WADA S2 category.
The 2026 Frontiers in Endocrinology review The emerging landscape of performance-enhancing peptides modulating GH-IGF1 axis: bridging the gap between clinical evidence and patient self-administration (PMID 42395176) lists CJC-1295 with and without DAC among the GHRH analogues "most commonly encountered in clinical practice and online self-administration protocols" and sets out the gap between the two 2006 pharmacology papers and the claims made for the compound online. In sum, the compound reliably raises GH and IGF-1 in humans for a week or more per dose, and nothing beyond that has been demonstrated in a controlled trial.
Theoretical concerns specific to the DAC
The pharmacology that makes CJC-1295 DAC interesting also generates its open questions, none of which has been tested in a trial:
- •Sustained IGF-1 elevation. IGF-1 is mitogenic, and prolonged supraphysiological IGF-1 is the mechanism by which acromegaly raises cancer risk. A single injection kept IGF-1 above baseline for up to 28 days in the 2006 study; repeated dosing produced accumulation. Whether the elevation produced by the compound reaches a level that matters is unknown, because no long-term study exists.
- •Loss of trough. Preserved pulsatility is reassuring, but the 7.5-fold rise in inter-pulse GH is itself a departure from physiology, and the metabolic consequences of continuously elevated basal GH (insulin resistance is the obvious candidate) were not examined beyond 49 days.
- •Albumin conjugation. The covalent bond to albumin cannot be reversed. If an adverse effect appears, the exposure cannot be stopped short of albumin's own turnover (around three weeks).
- •Immunogenicity. Peptide-albumin conjugates present a modified albumin epitope; anti-drug antibody data from the 2006 studies were not reported.
Research specifications
| Property | Value |
|---|---|
| Sequence | Tyr-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-Lys(maleimidopropionyl)-NH2 |
| Length | 30 residues (GRF 1-29 tetra-substituted plus DAC lysine) |
| Molecular weight | ~3,647.9 g/mol |
| Modifications | D-Ala2, Gln8, Ala15, Leu27; C-terminal Lys-maleimidopropionic acid (the DAC) |
| Binding partner in vivo | Serum albumin, cysteine-34, covalent thioether |
| Reported half-life (human) | 5.8–8.1 days for the albumin conjugate (PMID 16352683) |
| Common research formats | 2 mg and 5 mg lyophilised vials; 5 mg is the standard listing |
| Storage | Lyophilised at −20 °C; the maleimide is moisture- and thiol-sensitive, so reconstitute only with thiol-free diluent and use promptly |
| Analytical check | RP-HPLC purity; mass spectrometry confirming the intact maleimide (hydrolysed maleimide adds 18 Da and no longer conjugates) |
The maleimide is the quality-critical feature. A vial in which the maleimide has hydrolysed or reacted during storage is chemically "CJC-1295 no DAC with a dangling linker" and will behave like the short-acting peptide. Certificates of analysis rarely report maleimide integrity; see the COA interpretation guide for what to ask for.
CJC-1295 DAC on Peptides.SO: supplier pricing
The platform tracks two catalogue rows for the DAC form. The main 5 mg row has 40 listings from 24 suppliers, price-checked through 25 September 2026, with a median list price of $52.00, an interquartile range of $36.37 to $75.10, and a full range of $21.08 to $325; eight listings carry a discount. A second row labelled "CJC 1295 with DAC" (25 listings, 20 suppliers) has a median of $49.99. Taken together, 65 listings from 42 suppliers put the DAC form at a $50 median.
The comparison researchers usually want is with the no-DAC form, which is more widely stocked: 75 listings of the 5 mg no-DAC vial from 56 suppliers at a $64.95 median. The DAC version is the cheaper of the two on this platform, which is the opposite of what the added synthetic step would predict and probably reflects lower demand. Blends with ipamorelin (the most common GHRH/GHRP pairing) sit at $69 median across 29 suppliers for the no-DAC blend; DAC blends are rarer and are mostly single-supplier rows.
- •Current offers: CJC-1295 DAC 5 mg listings and CJC-1295 no-DAC 5 mg listings
- •Half-life comparison across GHRH analogues: half-life tool
- •Vetting a supplier: supplier checklist
Comparison with related compounds
Sermorelin. GRF 1-29 with no substitutions and no DAC; a few minutes of half-life and a single GH pulse per injection. It was an FDA-approved diagnostic and paediatric drug (Geref) before withdrawal for commercial reasons. See the sermorelin research profile.
Tesamorelin. GRF 1-44 with an N-terminal trans-3-hexenoic acid; FDA-approved (Egrifta) for HIV lipodystrophy on the phase 3 data cited above. Daily injection, no albumin binding. See the tesamorelin research profile.
Ipamorelin. Not a GHRH analogue at all but a ghrelin-receptor agonist that releases GH through a separate pathway; the two are combined on the reasoning that GHRH and ghrelin signalling are synergistic at the somatotroph. See CJC-1295 vs ipamorelin.
Frequently asked questions
What does the DAC actually do?
It is a maleimide group that forms a covalent bond with cysteine-34 of serum albumin within minutes of injection. The peptide then circulates attached to albumin, with a measured half-life of 5.8 to 8.1 days instead of minutes (PMID 16352683).
Does continuous stimulation abolish GH pulses?
No. Overnight sampling one week after injection showed unchanged pulse frequency and amplitude, with basal GH between pulses raised 7.5-fold (PMID 17018654).
Is there evidence for body-composition effects in humans?
No. The only human trials measured hormone levels and safety over 28 to 49 days. Body-composition claims are extrapolated from tesamorelin, a different molecule.
Why was it never approved?
ConjuChem stopped development in the mid-2000s and no sponsor has taken it further. Without efficacy trials there is nothing to approve.
Is it detectable in anti-doping tests?
Yes. Urinary LC-MS methods exist for CJC-1295 alongside sermorelin and tesamorelin (PMID 41138283), and GHRH analogues are prohibited by WADA.
Which is more expensive on this platform, DAC or no-DAC?
No-DAC: $64.95 median across 56 suppliers versus $52 for the DAC 5 mg vial across 24 suppliers, as of the 25 September 2026 price check.
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This article is for educational and research purposes only. CJC-1295 DAC sold through the suppliers listed on Peptides.SO is a laboratory reagent and is not intended for human or animal use. The 2006 trial regimens belong to those studies and are not guidance. Nothing on this page is medical advice.