What Is CJC-1295? With DAC vs Without DAC (Mod GRF 1-29), Sequence and CAS Numbers

By the Zen Well Labs Research Team · Last reviewed September 2026 · For laboratory research reference only

Short answer: “CJC-1295” is used in catalogues for two related but chemically distinct growth hormone–releasing hormone (GHRH) analogues. CJC-1295 with DAC is the long-acting construct carrying a Drug Affinity Complex (albumin-binding maleimidopropionyl linker): molecular formula C165H269N47O46, molecular weight ≈3647.2 Da, CAS 446262-90-4, PubChem CID 91971820. CJC-1295 without DAC is better identified as Modified GRF 1-29 (Mod GRF 1-29) the same tetrasubstituted GHRH(1-29) amide backbone without the albumin-binding group: formula C152H252N44O42, molecular weight ≈3367.9 Da, CAS 863288-34-0, PubChem CID 56841945. The mass difference of roughly 280 Da is how mass spectrometry separates them. Neither is FDA-approved; Zen Well Labs sells research peptides for in-vitro laboratory research only.

CJC-1295 at a glance

| Identifier | CJC-1295 with DAC | Modified GRF 1-29 (CJC-1295 no DAC) |

| — | — | — |

| Also called | Long-acting CJC-1295; CJC-1295 DAC | Mod GRF 1-29; tetrasubstituted GRF(1-29) |

| CAS number | 446262-90-4 | 863288-34-0 |

| PubChem CID | 91971820 | 56841945 |

| Molecular formula | C165H269N47O46 | C152H252N44O42 |

| Molecular weight | 3647.2 Da | 3367.9 Da |

| Peptide core | Tetrasubstituted human GHRH(1-29) amide | Same tetrasubstituted GHRH(1-29) amide |

| DAC element | C-terminal Lys with Nε-3-maleimidopropionamide (albumin-binding) | Absent |

| Typical supplied form | Lyophilized powder | Lyophilized powder |

| Regulatory status | Not FDA-approved for any use; research chemical | Not FDA-approved for any use; research chemical |

Shared backbone sequence

Both materials are built on a 29-residue amide analogue of the active N-terminal fragment of human GHRH (also historically called GRF 1-29 / sermorelin when unmodified). Relative to native GHRH(1-29), the Mod GRF / CJC backbone carries four substitutions that improve proteolytic stability: D-Ala at position 2, Gln at position 8, Ala at position 15, and Leu at position 27.

Three-letter sequence of the shared core (C-terminal amide):

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

In the DAC construct, an additional lysine residue bearing the maleimidopropionyl (Drug Affinity Complex) group is appended so the peptide can form a covalent adduct with free thiols on circulating albumin. That linker accounts for the ~279–280 Da mass increment between Mod GRF 1-29 (~3367.9 Da) and CJC-1295 with DAC (~3647.2 Da).

If a supplier’s label says only CJC-1295” without specifying DAC status, treat identity as unresolved until the Certificate of Analysis reports an observed mass near one of those two theoretical values.

Why vendors use one name for two molecules

ConjuChem and collaborators developed the albumin-binding GHRH analogue that entered the peer-reviewed literature as CJC-1295 that is, the DAC-bearing molecule. Research-chemical catalogues later began selling the shorter Mod GRF 1-29 peptide under the marketing shorthand CJC-1295 no DAC” or simply CJC-1295. The shorthand is convenient for shoppers and confusing for experimental design: pharmacokinetic papers on DAC-CJC-1295 do not transfer automatically to Mod GRF 1-29, and equal milligram amounts of the two contain different molar amounts of peptide.

A practical bench rule:

Observed MS mass ≈ 3647 Da with DAC (CAS 446262-90-4).
Observed MS mass ≈ 3368 Da → Mod GRF 1-29 / no DAC (CAS 863288-34-0).
Ambiguous label and no mass on the COA → quality red flag.

What has the published research looked at?

CJC-1295 with DAC

Peer-reviewed work on the DAC construct includes early clinical pharmacokinetic and pharmacodynamic studies in healthy adults. Teichman and colleagues (Journal of Clinical Endocrinology & Metabolism, 2006) reported prolonged elevation of circulating GH and IGF-I after subcutaneous administration of CJC-1295, with an estimated half-life on the order of several days (reported range about 5.8–8.1 days in the single-dose portion of that work). A related study (Ionescu & Frohman, JCEM, 2006) examined overnight GH pulsatility after CJC-1295 and reported that pulsatile secretion was preserved while trough and mean GH levels rose. These papers describe investigational pharmacology in controlled research settings; they do not constitute FDA approval, and they do not authorise consumer or athletic use.

Anti-doping and bioanalytical literature later published detection methods for CJC-1295 and related GHRH analogues in plasma matrices, reflecting the molecule’s appearance on prohibited-substance lists rather than any approved therapeutic status.

Modified GRF 1-29 (“no DAC)

Mod GRF 1-29 is studied and sold as a short-acting GHRH-receptor agonist relative to the albumin-bound DAC construct. Its literature is thinner as a named clinical entity because many papers discuss GHRH(1-29) analogues generically or in the context of the DAC programme. For laboratory work, the important point is receptor class: both molecules target the GHRH receptor on pituitary somatotrophs (distinct from the ghrelin / GHSR-1a pathway used by secretagogues such as ipamorelin).

What is missing

Neither CJC-1295 with DAC nor Mod GRF 1-29 is FDA-approved for any indication. There is no approved drug product under these research-chemical trade names. Growth hormone releasing factors and related analogues appear on the World Anti-Doping Agency Prohibited List. Claims that equate catalogue vials with a finished pharmaceutical, or that import athletic or body-composition framing into a research protocol, go beyond both the evidence and the legal status of these materials.

CJC-1295 and ipamorelin: different receptors

Catalogues and online discussions often pair “CJC-1295 with ipamorelin. Mechanistically they are not interchangeable:

CJC-1295 / Mod GRF 1-29 → GHRH receptor agonists (GHRH pathway).
Ipamorelin → GHSR-1a (ghrelin receptor) agonist.

The pathways converge on somatotroph GH release through distinct upstream signalling. Researchers studying GH-axis regulation in vitro therefore sometimes examine both classes in parallel — but the reagents remain chemically and pharmacologically separate. See our ipamorelin reference page for sequence and receptor details.

Storage and stability in the laboratory

Store lyophilized material sealed, dry and protected from light at −20 °C for long-term storage. After reconstitution for bench work, keep solutions at 2–8 °C, aliquot to avoid freeze–thaw cycles, and rely on your own stability data for working lifetimes. The maleimide-containing DAC construct is chemically more reactive than Mod GRF 1-29 alone; handle according to your lab’s SOP for thiol-reactive peptides and confirm identity after storage if the experiment depends on an intact DAC group. General principles are covered in our lyophilized peptide storage and stability guide. For reconstitution solvent choice in analytical or cell-culture settings, see bacteriostatic water vs sterile water.

How identity and purity are verified

Reversed-phase HPLC reports purity (percent peak area). Mass spectrometry confirms which analogue is in the vial: ≈3647 Da for with-DAC versus ≈3368 Da for Mod GRF 1-29. A Certificate of Analysis should state both results and a batch number. If a COA lists “CJC-1295” without a mass that matches one of the two theoretical values above, ask for clarification before using the material as a defined reference standard. Our guide on how to read a peptide COA explains each field.

Frequently asked questions

Is CJC-1295 the same as Mod GRF 1-29?

Not when DAC is present. Mod GRF 1-29 is the tetrasubstituted GHRH(1-29) amide without the albumin-binding group (CAS 863288-34-0, ≈3367.9 Da). CJC-1295 with DAC adds the Drug Affinity Complex (CAS 446262-90-4, ≈3647.2 Da). Catalogue labels that say “CJC-1295 no DAC” usually mean Mod GRF 1-29.

What is the amino acid sequence?

Shared core: 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, with D-Ala2, Gln8, Ala15 and Leu27 relative to native GHRH(1-29). The DAC form adds a C-terminal lysine carrying the maleimidopropionyl linker.

What are the CAS numbers and molecular weights?

With DAC: CAS 446262-90-4, 3647.2 Da, formula C165H269N47O46, PubChem CID 91971820. Without DAC (Mod GRF 1-29): CAS 863288-34-0, ≈3367.9 Da, formula C152H252N44O42, PubChem CID 56841945.

Is CJC-1295 FDA-approved?

No. Neither the DAC construct nor Mod GRF 1-29 is approved by the FDA for any use. Related GHRH analogues are named on the WADA Prohibited List.

Which form does a vial contain?

Only the mass (and ideally the CAS) on the Certificate of Analysis answers that. Do not infer DAC status from the product title alone.

What are Zen Well Labs CJC-1295 products intended for?

In-vitro laboratory research only. They are not for human or veterinary use. Confirm which analogue you ordered against the batch COA before experimental use.

References

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. Journal of Clinical Endocrinology & Metabolism. 2006;91(3):799–805.
Ionescu M, Frohman LA. Pulsatile secretion of growth hormone (GH) persists during continuous stimulation by CJC-1295, a long-acting GH-releasing hormone analog. Journal of Clinical Endocrinology & Metabolism. 2006;91(12):4792–4797.
PubChem Compound Summary, CID 91971820 (CJC-1295 with DAC). National Center for Biotechnology Information.
PubChem Compound Summary, CID 56841945 (Modified GRF 1-29 / CJC-1295 without DAC). National Center for Biotechnology Information.
World Anti-Doping Agency. Prohibited List, section S2 (Peptide hormones, growth factors, related substances and mimetics).

Research use only. All products sold by Zen Well Labs are intended strictly for in-vitro laboratory research. They are not drugs, foods, cosmetics or dietary supplements, are not approved by the FDA for any use, and are not for human or veterinary use. Nothing on this page is medical advice, and nothing here describes or recommends administration to humans or animals.

What Is CJC-1295?