Research Guides
CJC-1295 (Non-DAC) vs. CJC-1295 (DAC): What's the Difference?
CJC-1295 comes in two structurally distinct forms used in GHRH-pathway research. Understanding the difference helps researchers select the right variant for their study design.
The Core Difference: DAC
Both variants share the same 29-residue modified GHRH core sequence. The distinction lies in a single structural addition: CJC-1295 with DAC (Drug Affinity Complex) carries a C-terminal lysine group that allows the peptide to bind covalently to circulating albumin, a long-lived blood protein. CJC-1295 without DAC (Non-DAC) lacks this addition entirely.
How This Affects Half-Life
This one structural difference changes the peptide's behavior significantly. Because albumin circulates in the bloodstream for an extended period, the DAC variant's binding to it protects the peptide from rapid enzymatic breakdown and renal clearance. Research models show CJC-1295 with DAC can sustain GHRH-receptor activity over several days, while the Non-DAC form produces a shorter, more pulsatile signaling pattern that clears from the system more quickly.
Which Variant Fits Which Study Design
Neither variant is universally "better" — the right choice depends entirely on what a research protocol is designed to measure:
- Non-DAC: Better suited for studies examining acute GHRH-receptor signaling, pulse dynamics, or protocols requiring multiple dosing events within a single experimental session, since its shorter action window offers finer temporal resolution.
- DAC: Better suited for research into sustained GH-axis elevation, extended-exposure models, or protocols where fewer dosing events across a longer window are preferable.
Molecular Weight and Verification
Because both variants share a similar core sequence, mislabeling and misidentification are real risks with poorly characterized suppliers. The DAC variant has a molecular weight of approximately 3,647 Da, compared to roughly 3,367 Da for the Non-DAC form — a difference that mass spectrometry testing can confirm reliably. This is exactly why third-party purity testing and a Certificate of Analysis (COA) matter for every batch a lab works with, regardless of which variant is in use.
Choosing a Verified Source
Given how similar the two variants are in sequence, researchers should confirm any CJC-1295 product's identity and purity through independent lab testing before use. Apex Research Chemicals provides third-party tested CJC-1295 (Non-DAC) with a Certificate of Analysis available on the product page, so researchers can verify purity and identity before incorporating it into a study.
