Peptide comparison
CJC-1295 with DAC vs CJC-1295 without DAC
"CJC-1295" is sold as two different molecules. Both are built on the same modified 29-amino-acid GHRH sequence, often called Mod GRF 1-29. The form with DAC adds a linker that binds albumin in the blood, which turns a short-acting peptide into one that circulates for days. This page compares the two on structure, mechanism, half-life, evidence and regulatory status.
Reviewed by the Helica Labs research team · Last updated October 10, 2026
| CJC-1295 with DAC | CJC-1295 without DAC | |
|---|---|---|
| What it is | CJC-1295 with DAC A long-acting GHRH analogue developed by ConjuChem. Clinical development stopped in 2006. | CJC-1295 without DAC The same GHRH analogue without the DAC linker, also known as Modified GRF (1-29) or Mod GRF 1-29. A short-acting research peptide. |
| Sequence and composition | CJC-1295 with DAC GHRH(1-29) amide with four substitutions (D-Ala2, Gln8, Ala15, Leu27), plus an extra C-terminal lysine carrying a maleimidopropionic acid group: the "Drug Affinity Complex" (DAC). | CJC-1295 without DAC GHRH(1-29) amide with the same four substitutions (D-Ala2, Gln8, Ala15, Leu27). 29 amino acids, no linker. |
| Structure and mass | CJC-1295 with DAC About 3,647 Da (C165H269N47O46). The maleimide group bonds covalently to cysteine 34 of serum albumin. | CJC-1295 without DAC About 3,368 Da (C152H252N44O42). Does not bind albumin. |
| Proposed mechanism | CJC-1295 with DAC Binds GHRH receptors on somatotroph cells in the pituitary and stimulates release of the body's own growth hormone, which in turn raises IGF-1. Albumin binding keeps it circulating for days. In a small study, natural GH pulses were preserved while baseline GH between pulses rose. | CJC-1295 without DAC Same receptor and pathway. Without albumin binding it is expected to act briefly and give a short GH pulse. Three of the four substitutions make it more stable than natural GHRH: D-Ala2 resists cleavage by the enzyme DPP-IV, and Gln8 and Leu27 prevent deamidation and oxidation. Ala15 improves receptor binding. |
| Half-life | CJC-1295 with DAC About 6–8 days: 5.8–8.1 days after a single administration and 5.4–9.2 days with repeated administration in phase 1 trials (Teichman et al., 2006). | CJC-1295 without DAC Not established. No human pharmacokinetic study of this molecule has been published. For context, natural GHRH has a plasma half-life of about 7 minutes. |
| Evidence in humans | CJC-1295 with DAC Two small placebo-controlled phase 1 trials in healthy adults (Teichman et al., 2006) and one mechanistic study (Ionescu & Frohman, 2006). They measured hormone levels and safety, not clinical outcomes. A phase 2 trial was stopped in 2006 after a participant died; the treating physician attributed the death to underlying coronary artery disease. | CJC-1295 without DAC No published human pharmacokinetic or efficacy studies. In its December 2024 review, the US FDA stated that it found no studies establishing that CJC-1295 without DAC is pharmacologically active. |
| Regulatory status | CJC-1295 with DAC Not approved as a medicine anywhere. Prohibited at all times in sport: the WADA Prohibited List names CJC-1295 under S2 (GHRH and its analogues). In December 2024 an FDA advisory committee voted against adding it to the US compounding list. | CJC-1295 without DAC Not approved as a medicine anywhere. Also prohibited in sport under WADA S2 as a GHRH analogue. The same FDA advisory committee vote in December 2024 went against it. |
Key differences
- Same backbone, different lifetime: the DAC linker binds albumin and extends the half-life to about a week, while the form without DAC has no published half-life.
- Almost all human data are for CJC-1295 with DAC. They cannot be carried over to the peptide without DAC.
- The name "CJC-1295" is used for both molecules, by sellers and in some scientific papers. The form with DAC is about 280 Da heavier, so mass spectrometry on the certificate of analysis shows which one a vial contains.
- Both act on the GHRH receptor. Neither is growth hormone itself.
For research use only. Not for human consumption. Always verify against current literature.
Frequently asked questions
- What is the difference between CJC-1295 with DAC and without DAC?
- Both are the same modified 29-amino-acid GHRH analogue. The form with DAC carries an extra lysine with a maleimidopropionic acid group that binds albumin in the blood, which extends its half-life to about 6–8 days. The form without DAC (Mod GRF 1-29) does not bind albumin, and no human half-life has been published for it.
- Is Mod GRF 1-29 the same as CJC-1295?
- Mod GRF 1-29 is the usual name for CJC-1295 without DAC: GHRH(1-29) amide with four amino-acid substitutions (D-Ala2, Gln8, Ala15, Leu27). CJC-1295 with DAC is that peptide plus the albumin-binding linker.
- What is the half-life of CJC-1295 with and without DAC?
- With DAC, phase 1 trials measured 5.8–8.1 days after a single administration. Without DAC, no human pharmacokinetic study has been published, so half-life figures quoted online are estimates. Natural GHRH has a plasma half-life of about 7 minutes.
- How can a lab tell the two forms apart?
- By molecular mass. CJC-1295 without DAC is about 3,368 Da and the form with DAC about 3,647 Da, so mass spectrometry on the certificate of analysis identifies which one a vial contains.
- Are CJC-1295 with or without DAC approved, or allowed in sport?
- Neither form is approved as a medicine anywhere. WADA prohibits GHRH analogues at all times and names CJC-1295 on its list. Helica Labs supplies both strictly for laboratory research use.