CJC-1295 No DAC amplified growth hormone release in rodents

What is CJC-1295 No DAC?

CJC-1295 No DAC, more accurately called Modified GRF (1-29) or Mod GRF 1-29, is a synthetic analog of the first 29 amino acids of human growth hormone-releasing hormone (GHRH). Four amino acid substitutions make its backbone resistant to the enzyme DPP-IV, which normally clips native GHRH apart within minutes.

In Sprague-Dawley rats, this tetrasubstituted backbone produced a fourfold greater GH area-under-curve than unmodified GRF(1-29), and in vitro testing confirmed its DPP-IV resistance ^[1]. That rat work is a solid preclinical foundation. It shows the molecule's core engineering does what it was designed to do at the receptor and enzyme level, in rodents. It does not show what happens when this specific peptide, without the DAC group, is injected into a person.

How is CJC-1295 No DAC different from CJC-1295 with DAC?

CJC-1295 No DAC lacks the albumin-binding group that gives CJC-1295 with DAC a multi-day half-life. The DAC (Drug Affinity Complex) is a separate chemical addition that binds circulating albumin and converts a short-acting peptide into a long-acting one.

Removing DAC was an intentional design decision. The goal was rapid clearance and a sharp, pulsatile GH spike rather than sustained elevation. That deliberate change in exposure is why the no-DAC version's pharmacology cannot be assumed to match the DAC data ^[2].

The no-DAC half-life of roughly 30 minutes circulates widely across peptide forums and vendor literature. No human pharmacokinetic study supports it, so it remains a widely repeated but formally unsourced number.

What do the human CJC-1295 studies show?

Three published human papers make up the CJC-1295 clinical literature, and all three studied the DAC-bound, long-acting version ^[2]⁠^[3]⁠^[4]. None measured what happens after a subcutaneous injection of the short-acting, no-DAC form, at any dose, in any population.

Teichman and colleagues reported two placebo-controlled, double-blind ascending-dose trials in healthy adults aged 21 to 61. Single injections of CJC-1295 DAC at 30 or 60 mcg/kg raised GH 2- to 10-fold for six or more days and IGF-1 1.5- to 3-fold for 9 to 11 days, with no serious adverse events reported ^[2]. That multi-day elevation is the direct pharmacological consequence of albumin binding, the opposite of what a short-acting, no-DAC peptide is designed to produce.

Ionescu and colleagues gave a single CJC-1295 DAC injection to healthy men aged 20 to 40. Mean trough GH rose 7.5-fold (p < 0.0001) and overall IGF-1 rose 45% (p < 0.001), while the natural pulsatile pattern of GH secretion was preserved rather than flattened into a continuous plateau ^[3]. This study is the one most often cited for the idea that GHRH analogs "work with the body's rhythm." The finding is useful, and it was generated with the long-acting form.

Sackmann-Sala and colleagues ran serum proteomics in 11 healthy young men one week after a CJC-1295 DAC injection. They found shifts in apolipoprotein A1, transthyretin, and albumin fragment profiles consistent with GH/IGF-1 axis activation, with IGF-1 levels correlating to a specific immunoglobulin/albumin fragment ^[4]. The study is confirmatory biomarker data for the DAC compound, not evidence about the no-DAC peptide's downstream effects.

The entire human evidence base attached to the CJC-1295 name comes from a chemical sibling with a fundamentally different exposure profile. The CJC-1295 with DAC evidence covers what those trials do and do not establish.

What does the 2025 GHRH review say about human evidence?

A 2025 Nature Reviews Endocrinology review of GHRH agonists and antagonists states that human trials are still needed to confirm their clinical utility ^[5]. The review finds preclinical evidence across metabolic, cardiovascular, regenerative, and neuroprotective models strong enough to justify continued interest in the class ^[5].

That conclusion, written about the drug class, applies with full force to CJC-1295 No DAC. The field's own experts describe the human confirmation step as outstanding, not completed.

Where does the CJC-1295 No DAC dose come from?

The common CJC-1295 No DAC dose, 100 to 300 mcg injected two to three times daily on an empty stomach, comes from user reports and forum consensus. No pharmacokinetic trial of the no-DAC compound produced it, and no study validates a specific dose, frequency, or injection timing for this molecule in humans.

The schedule is a reasonable extrapolation from the plausible short half-life. It is still trial-and-error logic dressed in clinical-sounding numbers.

Storage advice follows the same pattern. Refrigeration, reconstitution with bacteriostatic water, and rapid use after mixing are standard peptide-handling caution, not steps tested against this compound's stability data in a published trial. How long reconstituted peptides last in the fridge covers the general handling question.

Is CJC-1295 No DAC with ipamorelin supported by a trial?

No controlled human trial has tested CJC-1295 No DAC combined with a ghrelin mimetic such as a GHRP or ipamorelin. The synergy rationale for the stack comes from separate GHRH and ghrelin-receptor physiology, not from a combined trial. What studies show for CJC-1295 and ipamorelin examines that combination in detail.

What side effects does CJC-1295 No DAC cause?

CJC-1295 No DAC side effects are known only from user reports, not from any controlled trial of the no-DAC peptide. Users describe transient flushing, a brief head-rush or tingling sensation right after injection, mild water retention, injection-site reactions, headache, lightheadedness, and increased hunger when it is stacked with a ghrelin mimetic.

Those effects are mechanistically plausible given what GHRH and ghrelin-receptor activation are known to do. They carry the evidentiary weight of anecdote, not trial data.

Product integrity is a separate, real concern with any research-use-only peptide obtained outside pharmaceutical channels. Impurity, mislabeling, and immunogenicity risk from unverified synthesis are a supply-chain issue layered on top of the pharmacology question, and the pharmacology does not resolve them.

What is still unknown about CJC-1295 No DAC?

CJC-1295 No DAC's human effects are inferred from three separate bodies of evidence: native GHRH physiology, the DAC sibling's confirmed endocrine effects ^[2]⁠^[3]⁠^[4], and animal-model backbone pharmacology ^[1]. None of the three has been combined and tested as a package in the short-acting, no-DAC molecule people inject. No trial has measured:

• Human half-life. The 30-minute figure has no human pharmacokinetic study behind it.
• GH pulse size. No study has measured the magnitude or duration of the GH pulse at forum-standard doses.
• Stacked effect. No trial has tested the peptide with a ghrelin mimetic.
• Efficacy. No human trial has measured body composition, sleep architecture, recovery markers, or any other efficacy endpoint.

The absence of a trial is not evidence that CJC-1295 No DAC does nothing. The mechanism is plausible, and the chemical class has real preclinical and DAC-variant human support. Plausibility inferred from a related compound is still a different category of evidence than a controlled trial of the compound itself, and that direct trial does not exist.