Nexa Peptides

CJC-1295 With DAC vs Without DAC, and the Ipamorelin Blend

Few growth hormone secretagogues generate as many search variants as CJC-1295. The compound exists in two forms (with and without the Drug Affinity Complex modification) and is most often paired with Ipamorelin, a selective ghrelin receptor agonist. The three options behave very differently in vitro and in study models. This page lays out the differences in plain scientific language so researchers can select the most appropriate variant for their protocol.

Research Overview

1. What CJC-1295 actually is

CJC-1295 is a synthetic analog of growth hormone releasing hormone (GHRH 1 to 29), engineered with four amino acid substitutions that improve receptor binding affinity and resistance to enzymatic degradation. By stimulating the somatotrophs of the anterior pituitary, it amplifies pulsatile growth hormone (GH) release without bypassing the natural feedback loop.

2. The DAC modification and what it changes

DAC stands for Drug Affinity Complex. It is a maleimidopropionic acid linker that covalently bonds the CJC-1295 peptide to circulating serum albumin after administration. That single modification is the entire reason researchers see two distinct half life profiles in the literature.

CJC-1295 with DAC: terminal half life of roughly 6 to 8 days. Once bound to albumin the peptide circulates for an extended period, producing a sustained elevation in basal GH and IGF-1 levels rather than discrete pulses.

CJC-1295 without DAC (also called Modified GRF 1 to 29, or Mod GRF 1 to 29): terminal half life of approximately 30 minutes. Without the albumin tether the peptide clears quickly, producing a sharp transient GH pulse that mirrors the body's endogenous secretion pattern far more closely.

Researchers studying chronic baseline elevation of GH/IGF-1 typically reach for the DAC variant. Researchers studying physiological pulsatility, or who want to dose around natural release windows (early morning, post training, pre sleep), typically reach for the no DAC variant.

3. Where Ipamorelin fits in

Ipamorelin is a pentapeptide ghrelin receptor agonist. It works on a different receptor pathway than CJC-1295: where CJC-1295 stimulates the GHRH receptor, Ipamorelin stimulates the growth hormone secretagogue receptor (GHSR-1a). The two pathways are synergistic in pituitary GH release.

Unlike older secretagogues such as GHRP-6 or hexarelin, Ipamorelin is highly selective. It does not appreciably elevate cortisol, prolactin, or aldosterone in study models, which is why it is the preferred pairing partner for CJC-1295 in most modern research protocols.

The combination is usually administered as the no DAC variant of CJC-1295 plus Ipamorelin, often as a pre mixed blend. Pairing the DAC variant with Ipamorelin is uncommon because the sustained CJC-1295 signal blunts the pulse Ipamorelin is meant to amplify.

4. Side by side

CJC-1295 with DAC: GHRH receptor agonist, half life 6 to 8 days, profile is sustained baseline elevation, dosing frequency once or twice weekly in study models.

CJC-1295 without DAC: GHRH receptor agonist, half life ~30 minutes, profile is sharp pulsatile release, dosing frequency one to three times daily in study models, aligned to natural GH windows.

CJC-1295 / Ipamorelin blend (no DAC): GHRH plus GHSR-1a dual pathway, half life ~30 minutes, profile is amplified pulsatile release through two complementary receptors, dosing frequency one to three times daily.

Ipamorelin alone: GHSR-1a agonist, half life ~2 hours, profile is selective ghrelin pathway pulse, often paired with a GHRH analog for synergy.

5. How researchers choose between the variants

The selection comes down to what the study is measuring. If the endpoint is steady state IGF-1 over weeks, the DAC variant gives a cleaner signal. If the endpoint is pulse amplitude, pulse frequency, or any measurement of physiological release pattern, the no DAC variant or the blend is the appropriate choice. The blend specifically gives researchers two distinct receptor pathway engagements in a single preparation, which simplifies protocol design where the goal is maximum pulse amplitude in a defined window.

6. Purity, lot testing, and reproducibility

Results across studies only generalize if the source material is consistent. Nexa Peptides supplies all three relevant variants (CJC-1295 No DAC, Ipamorelin, and the CJC-1295 / Ipamorelin No DAC blend) with lot specific Certificates of Analysis covering mass spectrometry identity confirmation and HPLC purity. CJC-1295 With DAC is not stocked at this time, in line with our current research customer demand profile.

7. Research use only

Every compound discussed on this page is supplied strictly for in vitro and animal research. Nothing here is intended for human use, veterinary use, diagnostic use, or therapeutic application.

Frequently Asked Questions

Is CJC-1295 with DAC the same compound as CJC-1295 without DAC?
The peptide backbone is the same modified GHRH 1 to 29 sequence. The DAC version has an additional maleimidopropionic acid linker that binds to serum albumin and extends the circulating half life from roughly 30 minutes to 6 to 8 days. The receptor target is identical; the pharmacokinetic profile is very different.
Why is CJC-1295 usually paired with Ipamorelin and not on its own?
CJC-1295 and Ipamorelin act on two different receptors in the pituitary (GHRH receptor and GHSR-1a). Engaging both pathways simultaneously produces a larger GH pulse than either compound alone in study models. The pairing also reduces the dose of each compound needed to hit a target signal.
Should CJC-1295 with DAC be combined with Ipamorelin?
It is uncommon. The sustained baseline elevation produced by the DAC variant blunts the discrete pulse that Ipamorelin is intended to amplify. Most research protocols that want both pathways engaged use the no DAC variant of CJC-1295 alongside Ipamorelin, often as a pre mixed blend.
What is Mod GRF 1-29?
Mod GRF 1-29 is the same molecule as CJC-1295 without DAC. The terminology is used interchangeably in research literature. Both refer to a four substitution variant of the first 29 residues of growth hormone releasing hormone.
Where can researchers verify purity?
Every Nexa Peptides shipment of CJC-1295 No DAC, Ipamorelin, and the CJC-1295 / Ipamorelin No DAC blend ships with a lot specific Certificate of Analysis. Purity is established by HPLC, identity by mass spectrometry. A digital copy of the lot COA is available at /verify/coa/[lot number].
Does Nexa Peptides carry CJC-1295 with DAC?
Not at present. Our current catalog covers CJC-1295 No DAC, Ipamorelin, and the pre mixed CJC-1295 / Ipamorelin No DAC blend. Researchers requesting the DAC variant for a specific protocol can contact support.
For Research Use Only (RUO). Not for human consumption, veterinary use, diagnostic use, or therapeutic purposes.