CJC-1295 without DAC, more precisely named Modified GRF (1-29), is a synthetic 29-amino-acid analog of growth hormone-releasing hormone (GHRH). It carries four amino-acid substitutions relative to the native GHRH(1-29) fragment (sermorelin) that researchers introduced to slow enzymatic breakdown, yet it lacks the albumin-binding Drug Affinity Complex (DAC) found in the longer-acting CJC-1295 DAC variant.1 An important caveat for interpreting the literature: the widely cited human studies of “CJC-1295” (Teichman 2006; Ionescu & Frohman 2006) used the DAC version, which binds endogenous albumin and persists for days.23 The no-DAC peptide described here is reported to have a much shorter circulating half-life (on the order of ~30 minutes) and does not have its own dedicated published human clinical trial; conclusions about it rest on mechanism and read-across from the GHRH class.1 CJC-1295 was never approved as a drug; its development reached early-phase clinical testing and was discontinued.4 This monograph is provided for research-use-only context and is not a recommendation for human use.
Sequence & identity
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-NH₂ · C₁₅₂H₂₅₂N₄₄O₄₂ · 3367.9 g/mol
Structure and identity per PubChem (CJC1295 Without DAC, CID 91976842; InChIKey XOZMWINMZMMOBR-UHFFFAOYSA-N); CAS 863288-34-0.5 The bare “CJC-1295” entry (CID 91971820, C₁₆₅H₂₆₉N₄₇O₄₆) corresponds to the DAC-modified variant and is distinct from the no-DAC peptide shown here.
Mechanisms studied
Researchers describe Modified GRF (1-29) as an agonist at the growth-hormone-releasing-hormone receptor (GHRHR), a Gs-protein-coupled receptor on anterior-pituitary somatotrophs. Receptor activation is reported to raise intracellular cAMP and activate protein kinase A, promoting calcium influx and release of stored growth hormone in a pulsatile manner.1 The four substitutions — D-Ala at position 2, Gln at 8, Ala at 15, and Leu at 27 — were reported to confer resistance to dipeptidyl peptidase-IV cleavage (position 2), reduce asparagine rearrangement (8), and limit methionine oxidation (27), so that the analog resists rapid metabolic clearance better than native GHRH(1-29) while retaining receptor activity.15 Unlike the DAC variant, the no-DAC peptide does not covalently bind albumin, which is why its reported duration of action is short.1
Dosing in the research literature
The figures below summarise regimens as reported in published research — they are not recommendations or directions for use.
| Source / model | Regimen reported | Notes |
|---|---|---|
| Ionescu & Frohman 2006 (CJC-1295 DAC variant; single SC dose)3 | Single subcutaneous doses of 60 or 90 µg/kg were administered in healthy men in this study of the albumin-binding (DAC) analog. | This regimen is for the DAC variant, not the no-DAC peptide; cited only to characterize the GHRH-analog class. Not a usage instruction. |
| Teichman et al. 2006 (CJC-1295 DAC variant; ascending dose)2 | Single ascending SC doses, and weekly/biweekly dosing, were studied; the authors noted the DAC compound was relatively well tolerated at doses around 30–60 µg/kg. | DAC variant, multi-day half-life (5.8–8.1 days). Does not apply to the short-acting no-DAC peptide. Reported for context only. |
| No-DAC peptide (Modified GRF 1-29) | No published human dose-finding trial of the no-DAC peptide itself was identified. | Reported half-life is short (~30 min), so any study-reported protocols for the DAC analog above cannot be transposed. Limited published data for this specific compound. |
Effects observed in research
Because the no-DAC peptide lacks its own dedicated human trials, reported effects are drawn from studies of the DAC analog and the broader GHRH class and should be read as class-level, study-reported observations rather than properties established for this exact compound. In healthy adults, Teichman et al. reported that single doses of the DAC variant produced dose-dependent increases in mean plasma growth hormone of roughly 2- to 10-fold and in IGF-I of about 1.5- to 3-fold, with effects persisting for days owing to albumin binding.2 Ionescu and Frohman reported that, despite continuous stimulation by the DAC analog, GH secretion remained pulsatile: basal GH rose about 7.5-fold and IGF-I rose roughly 45%, while GH pulse frequency was unchanged.3 For the short-acting no-DAC peptide, researchers describe a transient GHRH-receptor-mediated GH pulse consistent with the mechanism, but quantitative human outcome data specific to it are not established.1 No safety or efficacy claims for human use are made here.
Strength of evidence
Grade C. The direct human evidence base (Teichman 2006; Ionescu & Frohman 2006) concerns the DAC variant of CJC-1295, not the no-DAC peptide that is the subject of this monograph.23 Native GHRH and the related analog sermorelin (GRF 1-29) have a longer pharmacological track record, but the tetrasubstituted no-DAC peptide itself has limited published human data and no identified randomized controlled trial of its own. Support for it is therefore mechanistic and read across from the GHRH class. CJC-1295 was never an approved drug; per published accounts its clinical development was discontinued.4 Reported half-life of the no-DAC form is approximately 30 minutes, versus an estimated 5.8–8.1 days for the DAC variant.12 Values stated as “not established” reflect genuine gaps in the primary literature rather than omissions.
Reconstitution & storage
Reconstitute with bacteriostatic water for laboratory handling. Store lyophilised material frozen and reconstituted material refrigerated. Use Peptigo’s reconstitution calculator and storage cheat sheet for working figures.
References
- Modified GRF (1-29). Wikipedia. Summary of sequence, the four substitutions (D-Ala2, Gln8, Ala15, Leu27), GHRHR mechanism, and reported half-life (‘at least 30 minutes’ vs native ‘<10 minutes'). https://en.wikipedia.org/wiki/Modified_GRF_(1-29)
- Teichman SL, Neale A, Lawrence B, Gagnon C, Castaigne JP, Frohman LA. 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 Mar;91(3):799-805. DOI: 10.1210/jc.2005-1536. (Studied the DAC variant; half-life 5.8–8.1 days.) https://academic.oup.com/jcem/article-abstract/91/3/799/2843281
- Ionescu M, Frohman LA. Pulsatile secretion of growth hormone (GH) persists during continuous stimulation by CJC-1295, a long-acting GH-releasing hormone analog. J Clin Endocrinol Metab. 2006 Dec;91(12):4792-7. PMID: 17018654. DOI: 10.1210/jc.2006-1702. (DAC variant.) https://pubmed.ncbi.nlm.nih.gov/17018654/
- CJC-1295. Wikipedia. Notes DAC vs no-DAC distinction, the maleimidopropionyl-lysine/albumin DAC mechanism, ~6–8 day half-life of the DAC form, and that CJC-1295 was never approved and its clinical development was discontinued. https://en.wikipedia.org/wiki/CJC-1295
- PubChem CID 91976842 (CJC1295 Without DAC): MolecularFormula C152H252N44O42, MolecularWeight 3367.9, InChIKey XOZMWINMZMMOBR-UHFFFAOYSA-N; CAS 863288-34-0 corroborated by ChemicalBook (MW 3367.9). https://pubchem.ncbi.nlm.nih.gov/compound/91976842