CJC-1295 DAC vs No-DAC (Modified GRF 1-29): The Difference
By DoseGauge Editorial · Updated 2026-06-13 · 5 min read
CJC-1295 comes in two forms that differ mainly in how long they stay active. CJC-1295 with DAC carries a drug affinity complex that binds albumin and keeps it in circulation for several days. CJC-1295 without DAC is the same molecule as modified GRF 1-29 (also written mod GRF 1-29); it has a short plasma half-life on the order of roughly 30 minutes and is the form usually found in a CJC-1295 / Ipamorelin blend. Neither variant is approved by the FDA for human use. This page explains what DAC is, how the two forms compare, and why the difference matters. It is informational and educational only, not medical advice, and it does not recommend either form or any dose.
What "DAC" means
DAC stands for drug affinity complex. It is a chemical group added to the CJC-1295 peptide that lets the molecule bind reversibly to albumin, the most abundant protein in blood plasma. Because albumin circulates for a long time and is cleared slowly, a peptide that hitches to it is protected from the rapid breakdown that a free peptide would face. The practical result is a much longer time in circulation.
That long-acting property is what the original human study of the DAC-modified analog measured. In healthy adults, CJC-1295 produced prolonged, dose-dependent increases in growth hormone and IGF-1, and the authors estimated its half-life at 5.8 to 8.1 days (Teichman et al., 2006). A half-life measured in days, rather than minutes, is the signature of the albumin-binding, with-DAC form.
With-DAC vs no-DAC: the comparison
The two variants share the same core GHRH-analogue activity but diverge sharply in duration. The table below summarizes the difference.
| Variant | Also known as | Albumin binding | Approximate duration | Typical use |
|---|---|---|---|---|
| CJC-1295 with DAC | CJC-1295 DAC | Yes (drug affinity complex binds albumin) | Several days; half-life estimated at 5.8 to 8.1 days (Teichman et al., 2006) | Sold as a long-acting standalone variant |
| CJC-1295 without DAC | Modified GRF 1-29, mod GRF 1-29 | No | Short, on the order of roughly 30 minutes | The form usually paired with Ipamorelin in a blend |
The with-DAC duration comes from the study of the long-acting analog (Teichman et al., 2006). The no-DAC figure of roughly 30 minutes is a commonly reported value for modified GRF 1-29 and is presented here as a general figure, separate from that study.
Which one is in a CJC-1295 / Ipamorelin blend
Blends sold as CJC-1295 / Ipamorelin typically use the no-DAC form, that is, modified GRF 1-29. The reason is timing. The no-DAC variant produces a short, pulse-like signal rather than a multi-day plateau, and that pairs naturally with Ipamorelin, a selective growth hormone secretagogue whose own plasma half-life is short (Ipamorelin, PubChem CID 9831659). Pairing two short-acting peptides keeps the blend's action confined to a brief window rather than stacking a days-long DAC effect on top of a short pulse.
So when a product is labeled simply "CJC-1295" inside a blend, it is most often the no-DAC, mod GRF 1-29 form rather than the with-DAC variant. For a fuller explanation of the blend itself, see what the blend is.
Why the difference matters
The gap between a half-life of days and one of minutes is large enough that the two forms are not interchangeable, and the main practical consequence is how often a dose is taken. A days-long with-DAC variant and a roughly 30-minute no-DAC variant imply very different dosing rhythms, which is why knowing which form a product contains matters before doing any math.
What does not change is the arithmetic of converting a dose into the units to draw. Whichever form you are working with, the calculator on this site takes the vial strength and water volume you enter and returns the units to draw, plus how much of each peptide that draw contains. It performs that conversion only; it does not set a dose, a schedule, or a frequency, and it recommends nothing. Decisions about whether any peptide is appropriate, and how it would be used, belong with a licensed clinician.
CalculatorOpen the CJC-1295 / Ipamorelin dosage calculator ->Frequently asked questions
Is CJC-1295 the same as modified GRF 1-29?
The no-DAC form is. CJC-1295 without DAC is the same molecule as modified GRF 1-29 (mod GRF 1-29). CJC-1295 with DAC is a different variant: it adds a drug affinity complex that binds albumin and extends its time in circulation to several days (Teichman et al., 2006). So "CJC-1295" can mean either one, which is why the DAC distinction matters.
What is the half-life of CJC-1295 with DAC?
In the study of the long-acting, DAC-modified analog in healthy adults, the estimated half-life was 5.8 to 8.1 days (Teichman et al., 2006). That multi-day duration is the result of the drug affinity complex binding albumin. The no-DAC form (modified GRF 1-29) is much shorter-acting, on the order of roughly 30 minutes.
Which CJC-1295 is used with Ipamorelin?
Blends typically use the no-DAC form, modified GRF 1-29. Its short, pulse-like action pairs with Ipamorelin, a selective growth hormone secretagogue that is also short-acting (Ipamorelin, PubChem CID 9831659). A product labeled "CJC-1295" inside a CJC-1295 / Ipamorelin blend is therefore most often the mod GRF 1-29 variant, not the with-DAC one.
Is CJC-1295 FDA-approved?
No. Neither CJC-1295 variant, with DAC or without, is approved by the FDA for human use. Both are research peptides, and the human data on them is limited. Being sold inside a blend does not change that status. Consult a licensed clinician before using any peptide.
Informational and educational only. Not medical advice. DoseGauge computes from the values you enter and does not recommend a dose. Talk to a licensed clinician before using any peptide or GLP-1 medication.