Research and laboratory use only. Not for human consumption.
CJC-1295
CJC-1295 is a synthetic analogue of growth hormone-releasing hormone (GHRH) developed to extend the biological action of GHRH and investigate prolonged stimulation of the growth hormone and insulin-like growth factor-1 axis.
What is CJC-1295?
CJC-1295 is a synthetic peptide designed as an analogue of growth hormone-releasing hormone, commonly abbreviated GHRH.
GHRH is produced naturally within the hypothalamus and participates in the endocrine control of growth hormone secretion. It acts primarily on GHRH receptors expressed by somatotroph cells within the anterior pituitary.
Natural GHRH has a relatively short duration in circulation because it is rapidly metabolised. Researchers therefore investigated whether structural modifications could produce GHRH analogues with substantially longer biological activity.
CJC-1295 emerged from this area of research. The best-characterised form incorporated a Drug Affinity Complex (DAC) designed to interact with circulating albumin, thereby extending exposure to the peptide.
What does the name CJC-1295 mean?
Unlike names such as GHRP-6 or IGF-1, CJC-1295 is primarily a developmental compound designation rather than an abbreviation that directly describes its biological function.
Compound Summary
The compound was engineered from the biologically active region of GHRH with substitutions intended to improve stability and maintain activity at the GHRH receptor.
An important complication when researching CJC-1295 is that the name is not always used consistently. Scientific literature, regulatory documents and commercial terminology may distinguish between CJC-1295, CJC-1295 DAC and related salt forms.
These distinctions matter because different molecular forms can have different pharmacokinetic properties. Data obtained using the long-acting DAC-containing molecule should therefore not automatically be attributed to every substance marketed or described using the CJC-1295 name.
The historical human studies most commonly associated with CJC-1295 investigated the long-acting analogue designed to bind circulating albumin.
Why was CJC-1295 developed?
GHRH can stimulate the pituitary to release growth hormone, but native GHRH is rapidly cleared from circulation. Its short duration presented an obstacle to attempts to produce sustained GHRH-receptor stimulation.
Researchers therefore explored modified GHRH analogues that could remain biologically active for longer periods while continuing to work through the physiological GHRH receptor pathway.
CJC-1295 was investigated as one such long-acting analogue. Rather than supplying growth hormone directly, its mechanism depends upon stimulation of the body's existing pituitary growth-hormone secretory machinery.
GHRH-receptor stimulation begins the endocrine signalling pathway.
Somatotroph cells respond to GHRH-receptor activation.
Pituitary growth hormone secretion is increased.
GH signalling contributes to increased hepatic IGF-1 production.
What is DAC?
The Drug Affinity Complex is central to understanding the long-acting CJC-1295 investigated in the best-known human studies.
CJC-1295 with DAC
The DAC strategy was designed to allow the peptide to form a covalent attachment to circulating albumin after administration.
Albumin remains in circulation for much longer than unmodified GHRH. Association with albumin therefore substantially extends the apparent half-life and biological exposure of the analogue.
“CJC-1295 without DAC”
The phrase “CJC-1295 without DAC” is widely encountered outside the original clinical literature, but it should not be assumed to represent the same molecule studied in the major long-acting CJC-1295 trials.
Naming conventions surrounding CJC-1295 have been inconsistent, and regulatory assessments distinguish several CJC-1295-related substances.
Why was its long duration scientifically important?
One of the most distinctive findings from the early human research was the prolonged pharmacodynamic activity of CJC-1295.
In a randomized controlled study in healthy adults, researchers reported an estimated CJC-1295 half-life of approximately 5.8 to 8.1 days following administration of the long-acting analogue.
Growth hormone concentrations increased for several days, while IGF-1 remained elevated for a still longer period. Repeated exposure also produced evidence of a cumulative effect on IGF-1 concentrations.
These observations demonstrated the principle behind the DAC approach: a peptide normally associated with a short-lived signalling pathway could be engineered to produce substantially prolonged biological activity.
What has been studied in humans?
CJC-1295 differs from many experimental peptides discussed online because controlled human studies do exist. However, those studies were limited in size and duration.
Prolonged GH and IGF-1 stimulation
Teichman and colleagues evaluated CJC-1295 in healthy adults in randomized, placebo-controlled research examining pharmacokinetics and endocrine responses.
Growth hormone pulsatility
Ionescu and Frohman investigated whether prolonged GHRH-receptor stimulation would eliminate the normal pulsatile pattern of growth hormone secretion.
GH / IGF-1 biomarker research
Serum samples from healthy men exposed to CJC-1295 were subsequently investigated using proteomic techniques to examine biomarkers associated with activation of the GH/IGF-1 axis.
What these studies did not establish
Demonstrating endocrine activity in healthy volunteers is not equivalent to demonstrating long-term clinical efficacy for growth hormone deficiency, ageing, body composition or other proposed uses.
What did laboratory and animal research investigate?
Preclinical studies helped establish that the long-acting analogue could stimulate the GH/IGF-1 axis across experimental models.
Research in GHRH-knockout mice examined whether prolonged GHRH-receptor stimulation could restore growth-related endocrine signalling. CJC-1295 increased growth and affected GH/IGF-1 biology in this model.
These experiments were valuable for understanding mechanism and biological plausibility, but animal findings cannot by themselves establish therapeutic effectiveness or safety in humans.
Where does CJC-1295 sit in the research pathway?
The existence of human studies does not mean that a compound has completed pharmaceutical development or demonstrated clinical benefit.
Mechanistic and animal research exists for GHRH-receptor signalling and the long-acting analogue.
EstablishedControlled studies in healthy adults demonstrated endocrine and pharmacokinetic activity.
DemonstratedThe available evidence does not establish clinical effectiveness for the numerous uses sometimes attributed to CJC-1295.
Not EstablishedCJC-1295 has not progressed to an approved pharmaceutical indication.
Not ApprovedWhy are researchers interested in CJC-1295?
The scientific importance of CJC-1295 is primarily connected to its ability to manipulate the endogenous GHRH–GH–IGF-1 endocrine axis for an extended period.
This has made the compound relevant to research into GHRH pharmacology, growth hormone secretion, IGF-1 regulation, endocrine pulsatility and long-acting peptide drug design.
Growth hormone and IGF-1 influence many physiological processes, which explains why CJC-1295 has attracted wider interest. However, biological plausibility should not be confused with demonstrated clinical efficacy.
Claims involving muscle growth, fat loss, recovery, anti-ageing or general wellness require clinical evidence specific to those outcomes. The early CJC-1295 studies were not sufficient to establish those broad claims.
What is known about safety?
Safety information for CJC-1295 remains much more limited than would normally be available for an approved medicine.
Early clinical studies
Small human studies provided short-term information about exposure to CJC-1295, but they were not designed to establish the safety of chronic treatment in large patient populations.
This distinction is important because short-duration research in healthy adults cannot reliably characterize uncommon, delayed or population-specific adverse effects.
Regulatory concerns
FDA has identified potential concerns involving CJC-1295, including immunogenicity, peptide-related impurities and difficulties surrounding characterization of different forms of the substance.
FDA has also identified serious adverse events associated with CJC-1295, including increased heart rate and a systemic vasodilatory reaction, while emphasizing that available clinical data remain limited.
What does the evidence not establish?
Understanding the limitations of a research programme is as important as understanding its positive findings.
What is the current status of CJC-1295?
CJC-1295 remains an investigational compound rather than an approved pharmaceutical treatment.
The U.S. Food and Drug Administration has separately evaluated several CJC-1295-related bulk drug substances, including free-base, acetate and DAC-associated forms, in the context of pharmaceutical compounding.
In its assessment, FDA concluded that the available information was insufficient to establish clinical effectiveness for growth hormone deficiency and highlighted limitations in clinical safety data, nonclinical safety concerns and uncertainties surrounding the characterization and naming of different CJC-1295 substances.
At the December 2024 Pharmacy Compounding Advisory Committee meeting, the committee voted against including the evaluated CJC-1295-related substances on the 503A Bulks List.
This regulatory assessment should not be confused with the question of whether CJC-1295 has biological activity. Human studies clearly demonstrated effects on GH and IGF-1. The regulatory issue is whether sufficient evidence exists to establish quality, safety and clinical effectiveness for a proposed therapeutic use.
CJC-1295 research at a glance.
CJC-1295 was developed to overcome the short circulating duration of native GHRH and produce prolonged GHRH-receptor stimulation.
Human studies demonstrated prolonged increases in GH and IGF-1 following exposure to the long-acting analogue.
Researchers reported that GH secretion remained pulsatile despite continuous stimulation by long-acting CJC-1295.
Serum samples were studied for protein changes associated with activation of the GH/IGF-1 axis.
FDA reviewed multiple CJC-1295-related bulk substances and raised concerns about characterization, safety evidence and lack of demonstrated effectiveness for growth hormone deficiency.
CJC-1295 has human pharmacodynamic data but has not become an approved pharmaceutical treatment.
Selected references.
Key publications and regulatory materials used to understand the scientific development of CJC-1295.
Scientific & Educational Information
This profile is provided for educational and scientific purposes. CJC-1295 is an investigational compound and is not presented here as an approved treatment. Discussion of biological mechanisms, animal experiments, human studies or potential therapeutic areas describes scientific research and should not be interpreted as medical advice, a treatment recommendation or instructions for human use.
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