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The dad-test answer
DAC (Drug Affinity Complex) extends CJC-1295's half-life from minutes to about 6-8 days. The no-DAC form (also sold as Mod-GRF 1-29) gives natural pulsatile GH release; the DAC form gives a steady GH bleed. Most operators want pulses - that's why no-DAC plus ipamorelin is the standard stack. DAC is the simpler protocol if missing daily injections is the issue.
Who wins for what
| Use case | Who wins, and why |
|---|---|
| physiologic GH pulses |
no DAC (Mod-GRF 1-29) Short half-life means GH still releases in pulses - that's how the body's own GHRH works. |
| convenience, fewer injections per week |
with DAC Once or twice weekly dosing vs daily; useful when adherence is the limiting factor. |
| stacking with ipamorelin |
no DAC Both peptides are short-acting, so the combined pulse is clean; DAC + ipamorelin produces a sustained GH bleed plus a pulse, which is harder to interpret. |
| side-effect predictability |
no DAC Sustained GH elevation from DAC is more likely to drive water retention, glucose intolerance, and CTS-like symptoms. |
What the head-to-head data shows
DAC (Drug Affinity Complex) is a maleimide group that lets the peptide bind to circulating albumin, extending half-life from minutes to roughly 6-8 days - the modification originally engineered by ConjuChem and characterized in Teichman et al. 2006. The no-DAC form is the same 30-amino-acid GHRH analog (also sold as Mod-GRF 1-29 or CJC-1295 no-DAC) without the albumin tether - half-life around 30 minutes. Neither version is FDA-approved; both are research peptides sold by US compounding pharmacies and gray-market vendors. The physiologic argument for no-DAC: endogenous GHRH releases GH in pulses, primarily at night; mimicking that pattern produces results closer to natural GH-axis function than a sustained bleed.
Our honest call
For most operators running the GH-axis stack, no-DAC is the right call - it preserves the body's pulsatile release pattern, it stacks cleanly with ipamorelin, and the side-effect profile is more predictable. The pulsatility argument is well-grounded - Ionescu and Frohman 2006 showed that pulsatile GHRH delivery produces meaningfully different IGF-1 and GH responses than continuous infusion. DAC has one real use case: a person who cannot keep up with daily injections and needs a once-weekly protocol. The trade-off is steady-state GH elevation, which is biologically less natural and more likely to drive water retention and glucose issues. Read the CJC-1295 dosing breakdown for both versions.
Sources and citations
- Teichman et al., CJC-1295 with DAC in healthy adults, J Clin Endocrinol Metab 2006 (PMID 16352683)
- Ionescu and Frohman, GHRH analog mechanism review, J Clin Endocrinol Metab 2006
- Sigalos and Pastuszak, GH secretagogue review, Sex Med Rev 2018
- ConjuChem CJC-1295 development program (peer-reviewed pharmacokinetics)
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Last reviewed · 2026-05-07 · Page generated by Protocol One matrix engine. None of this replaces a doctor. Peptides are gray-market in the US for most uses. Talk to a real prescriber before you change anything.