CJC-1295 With and Without DAC: Understanding Two GHRH Analogue Research Peptides
25th Aug 2026
CJC-1295 With and Without DAC: Understanding Two GHRH Analogue Research Peptides
CJC-1295 is a synthetic analogue of growth hormone-releasing hormone (GHRH) that has been investigated for its ability to stimulate endogenous growth hormone (GH) secretion and influence the GH/IGF-1 axis.
CJC-1295 is commonly discussed in two forms: CJC-1295 with DAC and CJC-1295 without DAC. Although they are closely related, the presence or absence of the Drug Affinity Complex (DAC) produces a major difference in pharmacokinetic behaviour.
The DAC modification was specifically developed to extend the peptide's circulation time by promoting binding to serum albumin. Human clinical research has demonstrated prolonged GH and IGF-1 responses following administration of CJC-1295 with DAC.
What Is CJC-1295?
CJC-1295 belongs to the family of GHRH analogues.
GHRH is a naturally occurring hypothalamic hormone that signals the pituitary gland to release growth hormone. Rather than directly providing GH, GHRH analogues are designed to stimulate the body's own GH-producing cells.
The basic pathway can be simplified as:
GHRH analogue → GHRH receptor → Pituitary → GH → IGF-1
This makes CJC-1295 fundamentally different from recombinant human growth hormone, which supplies GH directly.
CJC-1295 was originally developed from human GHRH(1-29). The DAC modification was designed to substantially increase stability and duration of action. Experimental work demonstrated that the modified peptide could associate with albumin and remain in circulation considerably longer than native GHRH.
CJC-1295 With DAC
The DAC in CJC-1295 with DAC stands for Drug Affinity Complex.
The modification allows the peptide to bind to circulating albumin, which substantially extends its pharmacokinetic profile.
This is the defining difference between the two forms.
In a randomized, placebo-controlled human study, a single administration of CJC-1295 produced dose-dependent increases in mean plasma GH concentrations of approximately 2- to 10-fold for six days or more, while IGF-1 remained elevated for approximately 9–11 days. The estimated half-life was approximately 5.8–8.1 days.
These findings make CJC-1295 with DAC particularly interesting for research involving long-duration stimulation of the GH/IGF-1 axis.
CJC-1295 With DAC and GH
Growth hormone is normally released from the pituitary in pulses.
Researchers have specifically investigated whether long-acting CJC-1295 alters this pulsatile pattern.
Interestingly, a dedicated human study found that GH pulsatility was preserved following CJC-1295 administration. GH pulse frequency and pulse magnitude were not significantly changed, while baseline or trough GH concentrations increased substantially.
This is an important distinction from the common claim that CJC-1295 with DAC simply "flattens" GH secretion.
The available human research indicates that pulsatile secretion can continue while overall GH exposure increases.
CJC-1295 With DAC and IGF-1
One of the major downstream effects investigated with CJC-1295 is its influence on insulin-like growth factor-1 (IGF-1).
GH stimulates IGF-1 production, particularly in the liver, and IGF-1 plays an important role in many physiological processes involving growth and metabolism.
In the human CJC-1295 study, IGF-1 concentrations increased approximately 1.5- to 3-fold for 9–11 days following a single administration. With repeated administration, mean IGF-1 remained above baseline for considerably longer.
This sustained GH/IGF-1 response is one of the primary reasons CJC-1295 with DAC has become an important research compound.
CJC-1295 Without DAC
CJC-1295 without DAC is generally used to describe the shorter-acting GHRH analogue commonly referred to in peptide research as Modified GRF(1-29).
The absence of the Drug Affinity Complex means it does not have the same albumin-binding mechanism responsible for the prolonged half-life of CJC-1295 with DAC.
As a result, the two compounds should not be treated as pharmacokinetically interchangeable.
The short-acting form is primarily of interest when researchers want to investigate transient GHRH-receptor stimulation rather than the prolonged exposure associated with the DAC modification.
Why Does the Difference Matter?
The distinction can be summarised simply:
| Characteristic | CJC-1295 With DAC | CJC-1295 Without DAC |
|---|---|---|
| GHRH analogue | Yes | Yes |
| DAC modification | Yes | No |
| Albumin binding | Yes | No |
| Duration of action | Extended | Shorter |
| Research focus | Sustained GH/IGF-1 stimulation | Short-duration GHRH signalling |
| Human pharmacokinetic data | Substantial | Much more limited |
| GH response | Sustained increase demonstrated | Less well characterised clinically |
| IGF-1 response | Sustained increase demonstrated | Less well characterised clinically |
The strongest human pharmacokinetic and pharmacodynamic evidence is for CJC-1295 with DAC. Published clinical research directly establishing equivalent outcomes for the commonly marketed "no-DAC" product is much more limited.
CJC-1295 and the GHRH Receptor
Both forms are designed around the biological activity of GHRH.
GHRH binds to receptors on somatotroph cells within the anterior pituitary.
Activation of these receptors stimulates intracellular signalling pathways that promote GH synthesis and release.
This makes CJC-1295 particularly useful for researchers investigating the relationship between:
Hypothalamus → GHRH → Pituitary → GH → IGF-1
Because CJC-1295 acts upstream of GH, its effects depend partly on the ability of the pituitary to respond to GHRH signalling.
CJC-1295 and Natural GH Pulsatility
Growth hormone is not released at a constant rate.
Instead, the pituitary releases GH in pulses, with secretion influenced by factors including sleep, age, exercise, nutritional status and other hormones.
This pulsatile pattern is an important aspect of endocrine physiology.
Research into CJC-1295 has therefore examined not only total GH exposure but also the pattern of GH secretion.
In a controlled human study, CJC-1295 increased overall GH secretion while preserving pulsatile GH release. The major change was an increase in trough GH concentrations, contributing to higher mean GH and IGF-1 levels.
This provides an important scientific distinction between increasing GH availability and completely eliminating endogenous pulsatility.
CJC-1295 vs Ipamorelin
CJC-1295 is sometimes combined in research discussions with Ipamorelin, but the compounds act through different receptor systems.
CJC-1295 is a GHRH analogue and acts through the GHRH receptor.
Ipamorelin is a growth hormone secretagogue that acts primarily through the growth hormone secretagogue receptor (GHS-R).
| Feature | CJC-1295 | Ipamorelin |
|---|---|---|
| Peptide class | GHRH analogue | Growth hormone secretagogue |
| Primary target | GHRH receptor | GHS-R |
| Main biological effect studied | GH release through GHRH signalling | GH release through GHS-R signalling |
| GH pathway | GHRH-dependent | Secretagogue-dependent |
| Research interest | GH/IGF-1 axis | GH secretagogue pharmacology |
Because they operate through different signalling systems, researchers may investigate them independently or examine their combined effects in experimental models.
CJC-1295 and the GH/IGF-1 Axis
The GH/IGF-1 axis is a complex endocrine network.
Growth hormone released by the pituitary can stimulate IGF-1 production, which subsequently acts on tissues throughout the body.
The pathway is involved in numerous physiological processes, including:
- Growth
- Protein metabolism
- Bone physiology
- Tissue development
- Energy metabolism
- Cellular signalling
CJC-1295 provides researchers with a method of experimentally stimulating this axis upstream of GH.
Human studies with CJC-1295 have demonstrated measurable increases in both GH and IGF-1, providing evidence that the peptide can produce sustained endocrine effects.
Research Applications
CJC-1295 may be of interest to laboratories investigating:
Growth Hormone Secretion
Studying how GHRH receptor stimulation influences endogenous GH production.
GH Pulsatility
Examining the relationship between basal GH levels and pulsatile secretion.
IGF-1 Regulation
Investigating how changes in GH signalling influence downstream IGF-1 production.
GHRH Receptor Pharmacology
Studying receptor activation and intracellular signalling.
Endocrine Research
Investigating the broader physiological regulation of the GH/IGF-1 axis.
Peptide Pharmacokinetics
Comparing short-acting and long-acting peptide structures.
Albumin-Binding Technology
CJC-1295 with DAC is also an interesting example of how albumin binding can be used to extend the circulation time of a peptide.
What Does the Research Actually Show?
The human evidence for CJC-1295 with DAC is considerably stronger than the evidence available for the commonly marketed no-DAC form.
Controlled studies in healthy adults demonstrated dose-dependent increases in GH and IGF-1 following CJC-1295 with DAC, with effects persisting for days after administration.
A separate study demonstrated that GH secretion remained pulsatile while baseline GH concentrations increased, resulting in higher overall GH and IGF-1 levels.
By comparison, claims frequently made online regarding CJC-1295 without DAC—including precise half-life, dosing schedules and specific performance outcomes—often rely on extrapolation or non-clinical sources rather than equivalent controlled human trials.
This distinction is important when evaluating peptide research.
CJC-1295 and Human Performance Claims
CJC-1295 is frequently discussed online in connection with:
- Muscle growth
- Fat loss
- Recovery
- Sleep
- Anti-ageing
- Athletic performance
- Body composition
However, the existence of a biological effect on GH and IGF-1 does not automatically demonstrate that CJC-1295 produces all of these outcomes in healthy individuals.
A 2026 review of performance-enhancing peptides highlighted the limited regulatory evidence for physique and performance applications and the uncertainty surrounding unregulated peptide products.
For research purposes, it is therefore more accurate to describe CJC-1295 as a GHRH analogue used to investigate GH/IGF-1 signalling, rather than making unsupported claims about guaranteed improvements in physique or performance.
CJC-1295 Research Peptides
CJC-1295 10mg may be supplied in either a DAC or no-DAC formulation depending on the specific research material.
Researchers should verify the exact molecular identity of the material being investigated because CJC-1295 with DAC and CJC-1295 without DAC have substantially different pharmacokinetic properties.
Laboratory research may examine:
- GHRH receptor activation
- GH secretion
- IGF-1 production
- GH pulsatility
- Endocrine signalling
- Peptide stability
- Albumin binding
- Pharmacokinetics
- GH/IGF-1 axis regulation
Appropriate analytical verification and validated laboratory protocols should be used when working with biologically active peptide compounds.
Final Thoughts
CJC-1295 is an important research peptide within the field of growth hormone and endocrine pharmacology.
The most significant distinction is between the DAC and no-DAC forms.
CJC-1295 with DAC incorporates an albumin-binding modification that dramatically extends its circulation time. Controlled human research has demonstrated sustained increases in GH and IGF-1 following administration, with the GH response remaining pulsatile.
CJC-1295 without DAC is a shorter-acting GHRH analogue commonly investigated as Modified GRF(1-29), but the human clinical evidence for this form is much less extensive.
Understanding this difference is essential when evaluating CJC-1295 research, because DAC and no-DAC should not simply be considered two versions of the same pharmacokinetic profile.
For researchers investigating GHRH receptor signalling, GH pulsatility, IGF-1 regulation and endocrine pharmacology, CJC-1295 provides a valuable experimental model for studying the GH/IGF-1 axis.
CJC-1295 with DAC and CJC-1295 without DAC are intended for research purposes only and are not intended for human consumption or self-administration.
This article is provided for educational and research-information purposes only. It does not constitute medical advice, diagnosis or treatment guidance.
References
- Teichman SL, et al. Prolonged stimulation of growth hormone (GH) and insulin-like growth factor I secretion by CJC-1295, a long-acting analog of GH-releasing hormone, in healthy adults. Journal of Clinical Endocrinology & Metabolism.
- Ionescu M, Frohman LA. Pulsatile secretion of growth hormone (GH) persists during continuous stimulation by CJC-1295, a long-acting GH-releasing hormone analog. Journal of Clinical Endocrinology & Metabolism.
- Human growth hormone-releasing factor (hGRF)1-29-albumin bioconjugates activate the GRF receptor on the anterior pituitary in rats: identification of CJC-1295 as a long-lasting GRF analog.
- Dominikowski A, et al. The emerging landscape of performance-enhancing peptides modulating GH-IGF1 axis. Frontiers in Endocrinology, 2026.
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