CJC-1295, DAC & Modified GRF (1-29): Understanding the Names

The confusion is not accidental. A research name was attached, commercially, to a related but different molecule, and the citation trail followed the name rather than the structure. Untangling it requires going back to the original papers.

Evidence level: primary pharmacology papers, a granted patent, and clinical-trial registry records. Vendor descriptions are not treated as sources here.

The name first appears in a 2005 Endocrinology paper from ConjuChem. Three maleimido derivatives of human GH-releasing factor hGRF(1-29) were synthesised and bioconjugated to human serum albumin. The best-performing compound was designated CJC-1295: a tetrasubstituted form of hGRF(1-29) carrying an N-epsilon-3-maleimidopropionamide derivative of lysine at the C terminus. [1]

That paper reported a four-fold increase in growth-hormone area under the curve over two hours compared with unmodified hGRF(1-29) in rats, and detected the compound in plasma beyond 72 hours. Western blot showed the CJC-1295 immunoreactive species on the albumin band. [1] In other words, the defining feature of CJC-1295 as published is that it attaches itself to albumin.

The two human studies that carry the CJC-1295 name — Teichman and colleagues in healthy adults [2], and Ionescu and Frohman on pulsatility [3] — both studied this albumin-binding molecule.

DAC stands for Drug Affinity Complex. It is the technology platform behind the molecule: a reactive maleimide group placed on a peptide so that, after administration, it forms a covalent bond with the free thiol on cysteine-34 of circulating serum albumin. [1][4]

The purpose is duration. Albumin has a long circulating half-life, so a peptide tethered to it persists far longer than the free peptide would. In the CJC-1295 human studies, that translated into a half-life measured in days rather than minutes. [2]

DAC is therefore not an optional accessory to CJC-1295 in the published sense — it is the design feature that produced the compound's defining pharmacokinetics.

GRF(1-29), also written GHRH(1-29), is the first 29 amino acids of growth-hormone-releasing hormone — the shortest fragment that retains the hormone's activity at its receptor. Unmodified, it is degraded rapidly, largely by dipeptidyl peptidase-IV.

'Modified GRF (1-29)' refers to a version carrying amino-acid substitutions that resist that degradation, but without the albumin-binding maleimide group. It therefore has a short duration of action compared with the DAC-bearing molecule — the substitutions buy stability, not days of circulation.

The substituted-but-not-albumin-binding molecule does not have a body of peer-reviewed human literature under any of its common names. That absence, rather than any negative finding, is the honest characterisation of its evidence base.

The two names are frequently used as synonyms in commercial contexts. That usage cannot be confirmed from peer-reviewed sources, and this page will not state it as fact.

What can be established:

• CJC-1295 as published always includes the albumin-binding modification. [1]
• A product described as 'CJC-1295 no DAC' is, by its own description, lacking that modification — so it is not the published CJC-1295.
• Modified GRF (1-29) is the term ordinarily used for a substituted GRF(1-29) analogue without albumin binding.
• Whether any given 'no DAC' product has the same substitutions as any given 'Modified GRF (1-29)' product is a question about that specific material, answerable only by analysis of that material — not by the name on the label.

This is why identity testing on a certificate of analysis matters more than the product name. The name is a claim; the analysis is a measurement.

Because evidence attaches to molecules, not to names. Citing the Teichman half-life figures — derived from the DAC-bearing molecule in healthy adults [2] — in support of a product without that modification is a category error. The pharmacokinetics being quoted are a direct consequence of the feature the product does not have.

The same applies in the other direction: the absence of published human data for non-DAC analogues is not a criticism of them, and it is not evidence of harm. It is simply an absence, and it should be stated as one.

The pharmacological consequences of the DAC distinction are covered in detail in CJC-1295 with DAC versus without DAC.

A short checklist, applied before a paper is cited:

• Identify the exact molecule named in the methods, not the title or the abstract.
• Check the sequence and any modification — in particular whether an albumin-binding group is present.
• Check DAC status explicitly. If the paper predates or omits that term, look for maleimide, bioconjugate or albumin language. [1][4]
• Check the study model: cultured pituitary cells, rats, or humans. [1][2][3]
• Check the administration route and duration; a single-dose pharmacokinetic study does not describe repeated administration.
• Ask whether the evidence is about CJC-1295 at all, or about GRF(1-29) generally.

Clinical development of CJC-1295 did not continue to a completed, published human efficacy programme. One registered study in HIV-associated lipodystrophy is recorded as halted, with no results posted. [5] That is part of the evidence picture and belongs in any honest summary.

For the compound overview, see what CJC-1295 and ipamorelin are.

For receptor-level detail, see the CJC-1295 and ipamorelin mechanism guide.

For a source-by-source audit, see the CJC-1295 and ipamorelin evidence review.

For the two pathways side by side, see CJC-1295 vs ipamorelin.