CJC-1295 is one of the most widely referenced growth hormone-releasing hormone (GHRH) analog research peptides in contemporary peptide literature. A frequent source of confusion among new researchers is the distinction between CJC-1295 with DAC and CJC-1295 without DAC (sometimes called Modified GRF 1-29 or Mod GRF 1-29). Although they share the same base amino acid sequence, these two compounds behave very differently in research models.
What Is CJC-1295?
CJC-1295 is a synthetic analog of the first 29 amino acids of endogenous GHRH. Native GHRH is a 44-amino-acid peptide produced in the hypothalamus that stimulates the anterior pituitary to release growth hormone (GH). Research has established that the biological activity of GHRH resides primarily in its N-terminal 1-29 sequence.
CJC-1295 incorporates four specific amino acid substitutions into the GHRH 1-29 backbone. These substitutions protect the molecule from enzymatic degradation, particularly by dipeptidyl peptidase-4 (DPP-4), which rapidly inactivates native GHRH.
What Does "DAC" Mean?
DAC stands for Drug Affinity Complex. In the context of CJC-1295, DAC refers to the addition of a maleimido-propionic acid (MPA) moiety to the peptide. This chemical modification creates a reactive site that forms a covalent bond with cysteine-34 of serum albumin once the peptide enters circulation.
Albumin is the most abundant plasma protein and has a circulating half-life of approximately 19 days. By covalently linking to albumin, CJC-1295 DAC effectively "piggybacks" on the long half-life of albumin, extending its own circulating duration dramatically.
The Half-Life Difference: Minutes vs Days
- CJC-1295 without DAC (Mod GRF 1-29): Half-life of approximately 30 minutes in published research.
- CJC-1295 with DAC: Half-life of approximately six to eight days in published pharmacokinetic studies.
This roughly 300-fold difference in circulating duration is the single most important practical distinction between the two compounds.
Implications for Research Dosing Frequency
CJC-1295 without DAC is typically administered with greater frequency in published research protocols because its effect dissipates within hours. CJC-1295 with DAC, by contrast, is typically administered far less frequently because a single dose maintains elevated plasma concentrations for approximately a week.
Stable vs Pulsatile GH Release: A Key Research Distinction
Endogenous GH secretion is pulsatile, meaning the pituitary releases GH in discrete bursts throughout the day. CJC-1295 without DAC, with its short half-life, preserves a more pulsatile signaling pattern. CJC-1295 with DAC produces something very different: a sustained elevation in GHRH receptor activity, often described in the literature as a "GHRH bleed" or continuous low-grade stimulus.
This stable-vs-pulsatile distinction is the core functional difference that drives researchers to choose one form over the other based on their specific research question.
Why Researchers Choose One Over the Other
Researchers investigating pulsatile GH biology, circadian patterns of the GH axis, or questions where natural signaling fidelity is important often prefer CJC-1295 without DAC. Researchers investigating chronic GH axis modulation, long-term IGF-1 elevation, or research questions that benefit from simplified dosing schedules often select CJC-1295 with DAC.
Comparison to Sermorelin and Tesamorelin
Sermorelin is essentially unmodified GHRH 1-29 with no stabilizing substitutions. Its half-life is very short, typically cited as around 10 to 20 minutes.
Tesamorelin incorporates a trans-3-hexenoic acid modification at the N-terminus that provides moderate stabilization.
CJC-1295 with DAC sits at the far end of the half-life spectrum, offering the longest duration of action of any commonly referenced GHRH analog research peptide.
Common Research Applications
Both forms of CJC-1295 have been incorporated into a range of research investigations, including studies of GH axis regulation, IGF-1 kinetics, growth hormone secretagogue receptor interactions when combined with ghrelin mimetics, and broader metabolic research. Common pairings in published literature include parallel work with other widely-researched peptides such as BPC-157, TB-500, and Semax in multi-peptide research panels.
Sourcing CJC-1295 DAC in Canada
Canadian research laboratories require reliable sources of high-purity peptides with consistent batch-to-batch quality. Based Peptides supplies Canadian researchers with documented, research-grade CJC-1295 variants. Researchers can Buy CJC-1295 DAC in Canada directly from the Based Peptides catalog, which includes analytical documentation to support reproducible research work.
Based Peptides supports the Canadian research community with fast domestic shipping, cold-chain handling where appropriate, and transparent product specifications. Whether a protocol requires the pulsatile profile of Mod GRF 1-29 or the sustained profile of CJC-1295 DAC, selecting the correct variant is foundational to obtaining meaningful, interpretable research data.
Research Use Only Disclaimer
CJC-1295 (both with and without DAC) is a research peptide intended exclusively for laboratory investigation. It is not approved by Health Canada, the FDA, or any other regulatory authority for human consumption. Peptides sold by Based Peptides are for in-vitro laboratory research only.