CJC-1295 (No DAC)

Research summary

CJC-1295 without DAC, also sold as Mod GRF (1-29) or modified GRF 1-29, is a 29-amino-acid synthetic analogue of growth hormone-releasing hormone (GHRH) carrying four substitutions that make it more resistant to breakdown than the native sequence. It is the peptide backbone of CJC-1295 minus the albumin-binding drug affinity complex (DAC), so it lacks the multi-day half-life that defines the DAC compound¹. It is a laboratory tool for GHRH-receptor and growth hormone (GH) axis research; the published human studies of CJC-1295 used the DAC version².

Also known as

Mod GRF (1-29) · Modified GRF 1-29 · Tetrasubstituted GRF (1-29) · CJC-1295 without DAC

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-NH2

What is CJC-1295 without DAC?

Native GHRH was first isolated in 1982 as a 44-amino-acid peptide from a pancreatic tumor that had caused acromegaly³. Its first 29 residues, with a C-terminal amide, are the shortest synthetic fragment that keeps the hormone's full biological activity; that fragment is sermorelin⁴.

In 2005, researchers at ConjuChem described CJC-1295 as a tetrasubstituted form of human GRF(1-29) with an extra lysine, carrying a maleimidopropionamide group, added at the C terminus¹. The product sold as CJC-1295 without DAC (or no DAC) is the tetrasubstituted 29-residue amide on its own, without that lysine linker. When a Norwegian doping-control laboratory analyzed an unidentified preparation seized by police and customs, it found exactly this kind of peptide: a 29-amino-acid amide whose sequence matched the one being marketed as CJC-1295⁵.

The four substitutions and why they were made

Compared with the native human GHRH(1-29) sequence³, CJC-1295 without DAC differs at four positions:

The same design logic runs through earlier GRF-analogue work, in which peptides combining N-terminal, position-8, Ala15 and Leu27 changes were more stable in plasma and several-fold more potent than native GHRH in rat pituitary cells and in pigs⁶. Those were related analogues rather than this exact sequence, so they explain the rationale; they do not measure this peptide.

• Position 2, alanine to D-alanine. In human plasma, native GHRH is cut between residues 2 and 3 by dipeptidyl peptidase IV (DPP-IV), leaving a fragment with less than one-thousandth of the original activity⁷. A D-amino acid at position 1 or 2 prevented that cleavage⁸.
• Position 8, asparagine to glutamine. Asparagine 8 rearranges chemically in aqueous solution, and replacing it was used to reduce that isomerization⁶.
• Position 15, glycine to alanine. An alanine at position 15 had been shown to enhance receptor binding affinity⁶.
• Position 27, methionine to leucine. This removes a methionine that oxidizes in aqueous solution⁶.

How it differs from CJC-1295 with DAC

Native GHRH is short-lived: after intravenous administration in people, intact GHRH(1-44) had a half-life of about 6.8 minutes⁷. The DAC version of CJC-1295 addresses this with chemistry rather than sequence. Its reactive lysine bonds to the free thiol of cysteine 34 on serum albumin, and in rats the peptide was still present in plasma beyond 72 hours¹. In healthy adults its estimated half-life was 5.8 to 8.1 days².

CJC-1295 without DAC has none of that albumin-binding chemistry. Its substitutions are designed to slow enzymatic and chemical breakdown, but we found no published study that measured its half-life in people, so half-life figures quoted for it online are not backed by a peer-reviewed measurement. For a full side-by-side, see CJC-1295 with DAC vs without DAC.

What the research has examined

CJC-1295 analogues act at the GHRH receptor of the anterior pituitary¹, a G protein-coupled receptor expressed predominantly in that gland that signals through cyclic AMP⁹. That makes the no-DAC peptide a tool for laboratory work on somatotroph signaling, GH release, and how GHRH-receptor stimulation interacts with ghrelin-receptor agonists such as ipamorelin, the pairing supplied in the CJC-1295 + Ipamorelin vial.

Much of the literature that names it is analytical. Anti-doping laboratories have mapped the in vitro metabolism of CJC-1295 and CJC-1295 with DAC, alongside sermorelin and tesamorelin, and built mass-spectrometry methods to detect them, because GHRH and its synthetic analogues are prohibited in sport¹⁰. A 2026 clinical review listed both versions among unregulated GH-axis peptides and graded such compounds by strength of evidence, from regulatory-grade trials down to a complete absence of human studies¹¹.

Limitations of the evidence

• We found no published pharmacokinetic or controlled study in people of the 29-residue peptide on its own; the human data reported under the CJC-1295 name come from the DAC compound^2,12.
• The stability rationale is inferred from related analogues and enzyme studies^8,6, not from a head-to-head comparison with the DAC version or with sermorelin.
• Names are used loosely in unregulated supply chains, where product composition is uncertain¹¹. Identity is best confirmed by mass spectrometry. Every Peptides Only lot ships with a lot-matched certificate of analysis (HPLC purity and mass-spec identity) from an independent lab, published at our COA library.

Further reading

• CJC-1295 With DAC vs Without DAC (Mod GRF 1-29): How the Research Compares