Disclaimer: Information provided is for research and educational purposes only. Sermorelin is not approved by the FDA or any regulatory agency for therapeutic or cosmetic use.

Introduction

CJC-1295 is a synthetic analog of growth hormone–releasing hormone (GHRH), the natural hypothalamic peptide that signals the pituitary gland to release growth hormone (GH).¹²

It was developed as part of a broader effort to create longer-lasting and more stable GHRH analogs for studying GH secretion, IGF-1 signaling, and age-related changes in the somatotropic axis.³⁴

The name “CJC-1295” is often used in two ways. Technically, CJC-1295 refers to the long-acting DAC-modified analog designed to bind albumin and extend activity. In research and commercial settings, however, the term is also commonly used for CJC-1295 without DAC, also called Modified GRF (1-29) — a shorter-acting GHRH analog based on the active 1-29 region of GHRH.

CJC-1295 Fast Facts

Property	Details
Class	Growth Hormone–Releasing Hormone analog
Primary target	GHRH receptor on pituitary somatotroph cells
Main pathway	GHRHR activation → cAMP/PKA signaling → GH release → downstream IGF-1 signaling
Main research use	GH-axis signaling, pituitary stimulation, GH pulse dynamics, IGF-1 pathway research
Two common forms	CJC-1295 with DAC and CJC-1295 without DAC
Key distinction	DAC-modified CJC-1295 is long-acting; No DAC / Modified GRF (1-29) is shorter-acting
Not the same as GH	CJC-1295 stimulates endogenous GH release rather than supplying growth hormone directly

Chemical Structure

CJC-1295 is based on the active 1-29 amino-acid region of human GHRH. This region contains the core sequence required for GHRH receptor activation and growth hormone release.³⁴

The long-acting form, CJC-1295 with DAC, includes structural substitutions designed to improve stability, along with a drug-affinity-complex modification that enables albumin binding. This albumin-binding feature extends the compound’s half-life and produces a longer GH/IGF-1 signaling profile.⁵⁶

By contrast, CJC-1295 without DAC, commonly called Modified GRF (1-29), lacks the albumin-binding DAC component. It is still a modified GHRH analog, but it behaves as a shorter-acting research compound.

In simple terms: both forms are GHRH analogs, but the DAC version is engineered for extended circulation, while the No DAC version is built around shorter GHRH-like receptor activation.

How CJC-1295 Works (In Brief)

CJC-1295 works by mimicking GHRH and activating the GHRH receptor on pituitary somatotroph cells. This triggers intracellular cAMP/PKA signaling, which stimulates endogenous growth hormone release from the pituitary.³⁴

Growth hormone then acts on peripheral tissues, especially the liver, to support production of insulin-like growth factor 1 (IGF-1), a major downstream mediator of GH-axis activity.The key point is that CJC-1295 is not growth hormone. It acts upstream by stimulating the body’s GH-release pathway. The DAC form extends this signaling through albumin binding, while the No DAC form is shorter acting and more pulse-like.

Discovery & Research Milestones

The scientific background of CJC-1295 begins with the discovery of human growth hormone–releasing hormone in the early 1980s. Researchers identified GHRH from human pancreatic tumor tissue associated with acromegaly, then confirmed its sequence and biological activity.¹²

This discovery led to the development of shorter active GHRH fragments, including GHRH (1-29)-NH₂, later known as sermorelin. Researchers found that the first 29 amino acids of GHRH retained much of the hormone’s GH-releasing activity.³⁴

CJC-1295 was developed later as a more durable GHRH analog. The DAC-modified version was designed to extend biological activity through albumin binding, allowing researchers to study longer-duration GH and IGF-1 signaling.⁵⁶

Year	Study & Source	Key Finding
1982	Rivier J et al., Nature	Identified human growth hormone–releasing factor from pancreatic tumor tissue.¹.
1982	Guillemin R et al., Science	Independently confirmed the human GHRH sequence.²
1984–1985	Losa M; Barron J et al.	Established GHRH (1-29)-NH₂ and related analogs as potent GH secretagogues.³⁴
1990s	Modified GRF development	Amino-acid substitutions were explored to improve stability of GHRH (1-29)-based analogs.
2006	Teichman SL et al., JCEM	Long-acting CJC-1295 with DAC produced sustained GH and IGF-1 increases in healthy adults.⁵
2006	Ionescu M & Frohman LA, JCEM	GH secretion remained pulsatile during continuous stimulation by CJC-1295 with DAC.⁶
2009	Sackmann-Sala L et al., Clinical Cancer Research	Used CJC-1295-induced GH/IGF-1 axis activation to study downstream serum biomarkers.⁸

What Research Shows

Growth Hormone Stimulation

CJC-1295 acts upstream of the growth hormone itself. Instead of supplying GH directly, it activates the GHRH receptor on pituitary somatotroph cells, stimulating intracellular cAMP/PKA signaling and supporting endogenous GH release.³⁴

This makes CJC-1295 useful for studying how the pituitary responds to GHRH-like stimulation and how GH output affects downstream endocrine pathways.

IGF-1 Pathway Activation

Growth hormone released from the pituitary stimulates production of insulin-like growth factor 1 (IGF-1), especially in the liver. IGF-1 is one of the major downstream mediators of GH activity and is involved in anabolic signaling, tissue remodeling, and metabolic regulation.

In healthy-adult studies, long-acting CJC-1295 with DAC produced sustained increases in GH and IGF-1.⁵ Those findings apply specifically to DAC-modified CJC-1295, but they help explain why CJC-1295-class peptides are used in GH/IGF-1 axis research.

Preservation of GH Pulsatility

GH is naturally released in pulses, not as a flat continuous signal. One important finding from CJC-1295 DAC research is that GH secretion remained pulsatile even during extended stimulation.⁶

That matters because pulsatility is central to normal GH biology. It also helps distinguish GHRH analogs from direct GH replacement, which can create less physiologic exposure patterns.

Short-Acting vs. Long-Acting Research Models

The biggest practical distinction within the CJC-1295 category is whether the peptide includes DAC.

CJC-1295 with DAC is designed for longer exposure and sustained GH/IGF-1 stimulation. CJC-1295 without DAC, or Modified GRF (1-29), is shorter acting and more relevant to studies of transient GHRH receptor activation.

Both are GHRH analogs, but they should not be treated as interchangeable.

CJC-1295 With DAC vs. CJC-1295 No DAC

Feature	CJC-1295 with DAC	CJC-1295 No DAC / Modified GRF (1-29)
Technical identity	Original long-acting CJC-1295	Modified GRF (1-29), commonly called CJC-1295 No DAC
DAC extension	Yes	No
Albumin binding	Yes	No DAC-mediated binding
Duration profile	Long-acting	Shorter-acting
Main research use	Sustained GH/IGF-1 stimulation	Transient GHRH receptor activation
GH secretion pattern	Sustained elevation with pulsatility preserved in studies	Pulse-like GHRH analog research
Best description	Long-acting GHRH analog	Short-acting modified GHRH analog

The cleanest way to explain it: CJC-1295 with DAC is the long-acting albumin-binding version; CJC-1295 No DAC is the shorter-acting Modified GRF (1-29) version.

Read more about DAC vs no DAC here

CJC-1295 vs. Sermorelin

CJC-1295 belongs to the same broad GHRH analog family as sermorelin. Both are based on the active 1-29 region of GHRH and both stimulate the pituitary through the GHRH receptor.

The main difference is structural. Sermorelin is the simpler GHRH (1-29)-NH₂ fragment, while CJC-1295-related analogs include modifications designed to improve stability and duration.

Feature	Sermorelin	CJC-1295
Core identity	GHRH (1-29)-NH₂	Modified GHRH analog
Primary target	GHRH receptor	GHRH receptor
Main effect	Endogenous GH release	Endogenous GH release
Duration	Short-acting	Depends on DAC status
DAC version available	No	Yes
Research focus	GH testing, GH pulse physiology	GH-axis signaling, IGF-1 pathway research, sustained or transient stimulation models

Sermorelin is best understood as the simpler first-generation GHRH fragment, while CJC-1295 represents a more modified class of GHRH analogs.

Read more about CJC vs Sermorelin and other GH-secretogues here

Summary

CJC-1295 is a synthetic GHRH analog used to study the growth hormone axis. It works by activating the GHRH receptor on pituitary somatotrophs, stimulating endogenous GH release and downstream IGF-1 signaling.

The most important distinction is DAC status. CJC-1295 with DAC is the long-acting albumin-binding version originally developed to extend GHRH activity. CJC-1295 without DAC, commonly called Modified GRF (1-29), is shorter acting and used in research models focused on transient GHRH receptor activation.

In both forms, CJC-1295 remains scientifically relevant because it allows researchers to study GH-axis regulation upstream of growth hormone itself.¹–⁸

FAQs About CJC-1295

Related Articles

• How Does CJC-1295 Work?
• CJC-1295 Benefits
• CJC-1295 Side Effects & Safety
• CJC-1295 vs Ipamorelin and Other GH Secretogues
• CJC-1295 DAC vs No DAC
• What is Sermorelin?
• What is Ipamorelin?

References

1. Rivier J, Spiess J, Thorner MO, Vale W. Characterization of a growth hormone-releasing factor from a human pancreatic islet tumour. Nature. 1982;300(5889):276-278. https://pubmed.ncbi.nlm.nih.gov/6292724/
   
2. Guillemin R, Brazeau P, Bohlen P, et al. Growth hormone-releasing factor from a human pancreatic tumor that caused acromegaly. Science. 1982;218(4572):585-587. https://pubmed.ncbi.nlm.nih.gov/6812220/
   
3. Losa M, Schopohl J, von Werder K. Stimulation of GH with human GRF1-44, GRF1-40, and GRF1-29 in normal subjects. Klin Wochenschr. 1984;62(23):1109–1113. https://pubmed.ncbi.nlm.nih.gov/6240568/
   
4. Barron JL, Hopkins KD, Dunger DB, Hesp R, White A. GHRH (1-29)-NH₂ and a D-Ala² analog are potent stimulators of GH release in normal men. Clin Endocrinol (Oxf). 1985;23(4):399–407. https://pubmed.ncbi.nlm.nih.gov/2866496/
   
5. Teichman SL, Neale A, Lawrence B, Gagnon C, Castaigne JP, Frohman LA. Prolonged stimulation of growth hormone and insulin-like growth factor I secretion by CJC-1295, a long-acting analog of GH-releasing hormone, in healthy adults. J Clin Endocrinol Metab. 2006;91(3):799–805. https://pubmed.ncbi.nlm.nih.gov/16352683/
   
6. Ionescu M, Frohman LA. Pulsatile secretion of growth hormone persists during continuous stimulation by CJC-1295, a long-acting growth hormone-releasing hormone analog. J Clin Endocrinol Metab. 2006;91(12):4792–4797. https://pubmed.ncbi.nlm.nih.gov/17018654/
   
7. Soule S, et al. Incorporation of D-Ala² in growth hormone-releasing hormone (1-29)-NH₂: effects on metabolic clearance and biological activity. Clin Endocrinol (Oxf). 1994. https://pubmed.ncbi.nlm.nih.gov/7962295/
   
8. Sackmann-Sala L, et al. Activation of the GH/IGF-1 axis by CJC-1295, a long-acting GHRH analog. Clin Cancer Res. 2009. https://pmc.ncbi.nlm.nih.gov/articles/PMC2787983/