CJC-1295 NO DAC Peptide Research – Complete Guide

Table of Contents

• Quick Facts
• What Is CJC-1295 NO DAC?
• Chemical Structure and Technical Specifications
• Historical Development
• Mechanism of Action
• Pharmacokinetics and Metabolism
• Preclinical Research Findings
• Clinical Trial Data
• CJC-1295 NO DAC vs. CJC-1295 With DAC
• Research Applications
• Safety Profile and Tolerability
• Regulatory and Legal Status
• Research Limitations and Evidence Gaps
• Frequently Asked Questions
• References

Quick Facts

Compound Name	CJC-1295 NO DAC (Modified GRF 1-29)
CAS Number	863288-34-0
Molecular Weight	3367.9 g/mol
Molecular Formula	C152H252N44O42
Peptide Length	29 amino acids
Half-Life	30 minutes to 2 hours (rodent models)
Mechanism	GHRH receptor agonist; stimulates pulsatile GH release from anterior pituitary somatotrophs
Primary Research Areas	Growth hormone deficiency, body composition, muscle growth, metabolic health, aging
Research Stage	Predominantly preclinical; limited human data from CJC-1295 (DAC version) trials
WADA Status	Prohibited under Class S2 (peptide hormones, growth factors, related substances, and mimetics)
FDA Status	Not approved for any human indication; compounding nominations reviewed December 2024; PCAC recommended against 503A Bulks List inclusion
Key Distinction from DAC Version	No albumin-binding modification; 30-minute half-life vs. 5.8 to 8.1 days; preserves pulsatile GH pattern

What Is CJC-1295 NO DAC?

CJC-1295 NO DAC is a synthetic peptide comprising 29 amino acids, derived from the first 29 residues of endogenous growth hormone-releasing hormone (GHRH). It is also referred to as Modified GRF 1-29, Mod GRF 1-29, and CJC-1295 without DAC. The compound belongs to the class of growth hormone secretagogues: research compounds that stimulate the pituitary gland to release growth hormone rather than supplying growth hormone directly. The defining characteristic of CJC-1295 NO DAC is what it lacks. The “NO DAC” designation signals the absence of the Drug Affinity Complex (DAC) technology, a chemical modification present in the related compound CJC-1295 WITH DAC that enables covalent albumin binding and dramatically extends the compound’s plasma half-life from minutes to days. Without DAC, CJC-1295 NO DAC clears from plasma within 30 minutes to two hours, producing a brief, sharp stimulation of pituitary somatotrophs that mimics the episodic, pulsatile pattern of natural growth hormone release rather than generating continuous hormonal elevation [1,2]. Researchers study CJC-1295 NO DAC specifically because this short half-life is considered advantageous in research protocols where preservation of physiological hormone cycling is the goal. Natural growth hormone is not released at a constant rate. It is secreted in discrete pulses, most prominently during slow-wave sleep, with quieter intervals between pulses during which pituitary receptor sensitivity resets. Research tools that replicate this pulsatile architecture are useful for studying how growth hormone rhythm affects downstream biological outcomes, including IGF-1 production, lean tissue maintenance, fat metabolism, and cellular repair processes [2,3]. The compound is available as a research-grade lyophilized powder from licensed research chemical suppliers and is intended for laboratory research use only.

Chemical Structure and Technical Specifications

Amino Acid Sequence and Architecture

CJC-1295 NO DAC is a 29-residue linear peptide with the following sequence: Tyr-D-Ala-Asp-Ala-Ile-Phe-Thr-Gln-Ser-Tyr-Arg-Lys-Val-Leu-Ala-Gln-Leu-Ser-Ala-Arg-Lys-Leu-Leu-Gln-Asp-Ile-Leu-Ser-Arg This sequence corresponds to the first 29 amino acids of human GHRH, the residues responsible for full biological activity at the GHRH receptor. Research established early that GHRH (1-29) retains the complete receptor-binding and signaling capacity of the full 44-amino acid parent molecule, making the truncated fragment the logical starting point for analog development [3,4].

Key Structural Modifications

Four amino acid substitutions distinguish CJC-1295 NO DAC from unmodified native GHRH (1-29), located at positions 2, 8, 15, and 27 in the peptide chain. These substitutions were engineered for a specific and limited purpose: to resist enzymatic cleavage, particularly by dipeptidyl peptidase-IV (DPP-IV), the protease responsible for rapid degradation of the natural GHRH sequence at the N-terminus [4,5]. Native GHRH (1-29) degrades within minutes in plasma because DPP-IV cleaves between positions 2 and 3 of its sequence. The substitution at position 2 (D-Ala for the natural L-Ala) blocks this cleavage site directly. Critically, these modifications are designed only to extend the compound’s effective half-life enough to be useful in research protocols, not to fundamentally alter the pharmacological profile or receptor binding selectivity of the peptide. Receptor binding affinity at the GHRH receptor is preserved, and the compound continues to function within normal physiological feedback loops rather than overriding them [1,5].

Physical and Chemical Properties

The molecular formula is C₁₅₂H₂₅₂N₄₄O₄₂ with a molecular weight of 3367.9 g/mol. The compound carries CAS number 863288-34-0. It is water soluble and soluble in physiological buffers, with a PubChem CID of 91976842. In lyophilized form, storage at -20 degrees C is standard. Once reconstituted, the peptide solution is stored at 2 to 8 degrees C and used within a timeframe consistent with peptide stability guidelines for research applications. No albumin-binding reactive group is present in the structure, which is the fundamental distinction separating this compound from the DAC-modified version.

Historical Development

Origins in GHRH Biology

The scientific foundation for CJC-1295 NO DAC begins with the identification of growth hormone-releasing hormone itself. GHRH was first characterized in the early 1980s from pancreatic tumor tissue in patients with acromegaly caused by ectopic GHRH secretion. Structural analysis quickly revealed that the first 29 amino acids of the 44-residue native peptide contained the complete receptor-binding domain, and early analog research by Lance and colleagues in 1984 established that super-active analogs of GRF (1-29) could be constructed with modifications at key positions to enhance potency or stability [3]. Parallel research during the same period established why short-acting GHRH analogs would be scientifically valuable. Studies by Clark and Robinson in 1985 demonstrated that the pulsatile rhythm of growth hormone delivery, rather than continuous exposure, was critical to generating downstream biological responses including IGF-1 production and lean tissue effects [6]. This finding established the pharmacological rationale for short-acting GHRH analogs: a compound that produces brief, discrete stimulation of pituitary somatotrophs would preserve the episodic hormone architecture that the biological system is tuned to respond to.

Enzymatic Stability Research

Frohman and colleagues characterized DPP-IV and trypsin-like enzymatic degradation pathways for GHRH analogs in 1989, providing the biochemical roadmap for which structural positions to modify to extend stability without altering receptor pharmacology [5]. This work directly informed the design of the four amino acid substitutions that define Modified GRF 1-29. Bridon and colleagues published studies on long-lasting GRF derivatives in 1998, expanding the understanding of how structural modifications influenced compound half-life across a spectrum from the very short (minutes) to the very long (days via albumin binding) [7].

Formal Identification of CJC-1295

The compound most commonly called “CJC-1295” in the research literature was formally described by Jette and colleagues in 2005, who identified its albumin-binding (DAC) version as a long-lasting GRF analog in rats [1]. The same year, studies by Alba and colleagues in GHRH knockout mice provided foundational preclinical data on how GHRH receptor agonists affect growth, body composition, and pituitary function in deficiency models, data that informed subsequent research using both DAC and NO DAC formulations [8]. The pivotal human pharmacology study by Teichman and colleagues published in 2006 examined the DAC version in healthy adults and provided the reference clinical dataset from which the NO DAC version’s comparative pharmacological profile is inferred [2]. The Ionescu and Frohman study also published in 2006 in the Journal of Clinical Endocrinology and Metabolism examined pulsatility preservation under GHRH analog exposure, providing the mechanistic framework that distinguishes short-acting from long-acting GHRH approaches in research contexts [9].

Regulatory History

In December 2024, the FDA’s Pharmacy Compounding Advisory Committee (PCAC) reviewed nominations to include CJC-1295 on the 503A Bulks List, which governs which compounds can be used in compounding pharmacies for patient-specific prescriptions. The PCAC recommended against inclusion, citing insufficient evidence of clinical necessity and safety to support compounding use. This decision has no bearing on CJC-1295 NO DAC’s status as a legitimate laboratory research compound but is relevant context for understanding the regulatory environment surrounding GHRH analog peptides.

Mechanism of Action

GHRH Receptor Activation

CJC-1295 NO DAC acts as a selective agonist at the growth hormone-releasing hormone receptor (GHRHR), a G-protein coupled receptor expressed on somatotroph cells in the anterior pituitary gland. Binding of the peptide to GHRHR initiates a well-characterized intracellular signaling cascade: receptor activation stimulates adenylyl cyclase, which increases intracellular cyclic adenosine monophosphate (cAMP) concentrations. Elevated cAMP activates protein kinase A (PKA), which phosphorylates downstream transcription factors including CREB (cAMP response element-binding protein). This sequence enhances transcription of the GH gene, increases GH synthesis, and triggers release of pre-formed growth hormone from secretory vesicles within somatotroph cells [1,9]. Because the peptide clears from plasma within 30 minutes to two hours, this activation signal is episodic rather than sustained. The pituitary receptor is activated, GH is released in a discrete pulse, and the receptor returns to baseline sensitivity before the next stimulation event. This pattern replicates the episodic architecture of natural growth hormone secretion, which is governed in healthy physiology by alternating GHRH and somatostatin pulses from the hypothalamus [6,9]. Somatostatin is the inhibitory counterpart to GHRH: it suppresses GH release during inter-pulse intervals and resets pituitary somatotroph sensitivity. CJC-1295 NO DAC operates within this existing feedback framework rather than overriding it, which is the core mechanistic distinction between pulsatile GHRH analogs and exogenous GH administration. This is also pharmacologically distinct from the ghrelin/GHS-R pathway targeted by peptides such as ipamorelin. GHRHR and the ghrelin receptor (GHS-R1a) are separate receptor systems that can be activated simultaneously for additive GH secretion in combination research protocols, but CJC-1295 NO DAC engages only the GHRH receptor pathway.

IGF-1 Stimulation via the GH-Liver Axis

Growth hormone released by the pituitary following GHRHR activation travels in circulation to the liver, where it binds hepatic GH receptors and activates the JAK-STAT signaling pathway. This cascade drives transcription of the IGF-1 gene in hepatocytes, resulting in increased circulating insulin-like growth factor 1 (IGF-1) [8]. In animal model studies, CJC-1295 analog exposure produced approximately 28% increases in IGF-1 levels. Notably, IGF-1 elevations persist for 24 to 48 hours following a single peptide dose despite the compound clearing from plasma in under two hours, reflecting the delayed and sustained nature of IGF-1 synthesis and secretion relative to the upstream GH signal [2,8]. IGF-1 mediates many of the tissue-level effects associated with growth hormone activity. In skeletal muscle, IGF-1 promotes protein synthesis through the PI3K-Akt-mTOR signaling axis, supports satellite cell activation for muscle fiber repair and growth, and reduces protein catabolism by suppressing the ubiquitin-proteasome degradation pathway. In bone, IGF-1 receptor signaling on osteoblasts promotes collagen synthesis and mineral deposition, supporting skeletal density. In adipose tissue, the combined actions of GH (which directly activates hormone-sensitive lipase to mobilize triglycerides) and IGF-1 shift energy substrate utilization toward fat oxidation [2,8].

Lipolytic and Metabolic Effects

Growth hormone exerts direct lipolytic effects in adipose tissue independent of IGF-1. GH binding to receptors on adipocytes activates hormone-sensitive lipase, an enzyme that hydrolyzes stored triglycerides into free fatty acids and glycerol. These fatty acids enter circulation and become available as fuel for metabolic processes in muscle, liver, and other tissues. Research in animal models demonstrates preferential loss of visceral adipose tissue relative to subcutaneous fat under GHRH analog exposure, improved glucose tolerance in insulin-resistant models, and favorable changes in lipid profiles including reduced triglycerides and improved HDL ratios [8,10]. These effects emerge within two to four hours of administration and persist beyond peptide clearance.

Circadian and Sleep Architecture Integration

Endogenous growth hormone secretion follows a pronounced circadian pattern, with the largest pulse of the day occurring within the first period of slow-wave (deep) sleep, typically 60 to 90 minutes after sleep onset. CJC-1295 NO DAC administered in proximity to this timing window amplifies the natural nocturnal GH surge by providing additional pituitary somatotroph stimulation at the moment of peak secretory readiness. Animal sleep architecture studies have found that GHRH analog administration increases the duration and depth of slow-wave sleep phases and enhances GH pulse amplitude during these periods [10]. The interaction between GHRH signaling and sleep homeostasis is bidirectional: GHRH itself promotes non-REM sleep through actions in the hypothalamus, and slow-wave sleep in turn provides the optimal pituitary environment for GH pulse generation.

Receptor Sensitivity Preservation

Continuous, uninterrupted stimulation of GHRHR leads to receptor downregulation through internalization and reduced surface receptor density, a pharmacological process called desensitization. Long-acting GHRH analogs that maintain sustained plasma concentrations over days produce measurable GHRHR downregulation in animal models, potentially reducing the magnitude of GH secretion per unit of stimulus over time. The pulsatile stimulation pattern produced by CJC-1295 NO DAC, with inter-dose intervals long enough for receptor recovery, is associated with maintenance of receptor sensitivity across repeated dosing in rodent experiments [9]. This anti-desensitization property is central to the research rationale for using the NO DAC formulation in protocols designed to study chronic GH axis modulation.

Pharmacokinetics and Metabolism

Absorption and Distribution

CJC-1295 NO DAC is administered subcutaneously in research settings, the route producing the most reproducible absorption kinetics for peptide compounds of this size. Following subcutaneous injection, plasma concentrations rise within 15 to 30 minutes as the peptide diffuses from the injection depot into systemic circulation. Peak plasma concentrations are achieved within 30 to 60 minutes in rodent pharmacokinetic models. The compound distributes systemically and reaches GHRH receptors in the anterior pituitary within approximately 15 to 30 minutes of administration. Critically, CJC-1295 NO DAC does not bind to plasma albumin. The absence of the Drug Affinity Complex modification means the compound remains free in plasma without the carrier-mediated reservoir effect that extends the DAC version’s half-life. This free-peptide status allows rapid receptor engagement and equally rapid clearance.

Metabolism and Elimination

The primary metabolic challenge for any GHRH analog in plasma is enzymatic cleavage. Native GHRH (1-29) is degraded in minutes by DPP-IV acting at the N-terminal Tyr-Ala bond and by endopeptidases at internal positions. The four amino acid substitutions in CJC-1295 NO DAC, particularly the D-Ala substitution at position 2, block DPP-IV access to the N-terminus, extending the plasma half-life to 30 minutes to two hours depending on species, dose, and metabolic conditions [4,5]. This represents a meaningful extension of activity relative to native GHRH while still permitting complete clearance within a single daily dosing window. Metabolism proceeds through peptidase-mediated fragmentation, with the resulting amino acid fragments subject to renal clearance. Clearance rates in animal models correlate with kidney function, consistent with renal elimination of peptide metabolites. No accumulation of intact peptide or biologically active metabolites has been detected in repeated-dosing rodent studies. Complete elimination typically occurs within six to eight hours of administration.

The Pharmacokinetic-Pharmacodynamic Disconnect

A defining feature of CJC-1295 NO DAC’s pharmacological profile is the substantial disconnect between how long the peptide remains in plasma and how long its biological effects persist downstream. This relationship is summarized in published pharmacokinetic analyses and is relevant to understanding why short plasma half-life does not preclude sustained downstream effects:

Parameter	Duration
Peptide plasma half-life	30 minutes to 2 hours
GH elevation persistence	4 to 6 hours post-administration
IGF-1 elevation persistence	24 to 48 hours after single dose
Complete peptide clearance	6 to 8 hours

The explanation for this disconnect lies in the nature of GHRHR signaling. A brief burst of receptor activation triggers transcriptional and secretory programs within somatotrophs that continue operating after the stimulus has cleared. GH stored in secretory vesicles continues to be released over the following hours. IGF-1 synthesis in the liver, once initiated by GH receptor activation, proceeds over the 24 to 48 hour window required for transcription, translation, and protein secretion. This cascade architecture means that short peptide exposure drives effects lasting far beyond the peptide’s presence in circulation [2,8].

Preclinical Research Findings

Growth Hormone Deficiency Models

The most detailed preclinical mechanistic dataset for CJC-1295 NO DAC comes from studies using GHRH knockout (GHRHKO) mice, animals that lack endogenous GHRH and consequently develop growth hormone deficiency, growth retardation, and abnormal body composition. Alba and colleagues published findings in 2006 using daily administration at 2 micrograms per animal in this model [8]. Treated GHRHKO mice showed normalization of body weight and body length compared to untreated knockout controls, restoration of GH-dependent organ development, increased somatotroph cell proliferation within the pituitary, and increased pituitary GH mRNA expression. Lean-to-fat body composition ratios normalized toward wild-type values, and bone length measurements returned to control ranges. Effects were maintained when dosing intervals were extended to 24 to 48 hours, consistent with the documented persistence of IGF-1 elevation beyond each dose. These findings established that GHRH receptor agonist peptides structurally related to CJC-1295 NO DAC can restore growth and body composition parameters in a genetic deficiency model through pituitary somatotroph stimulation.

Muscle Growth and Protein Synthesis Research

Rodent studies using CJC-1295-related GHRH analogs in exercise and muscle injury recovery models have reported GH level increases ranging from 70% to 107% over 12-hour observation windows following experimental protocols [2]. Histological analysis of muscle tissue in treated animals has identified increased myofiber cross-sectional area, enhanced satellite cell activation confirmed by immunohistochemistry, and upregulation of GH and IGF-1 mRNA expression in skeletal muscle. Satellite cells are the resident stem cell population responsible for muscle fiber repair and hypertrophy following mechanical stress: their activation by IGF-1 signaling drives fusion with damaged fibers and synthesis of new contractile protein. Enhanced collagen synthesis has also been reported in some rodent tissue studies, relevant to connective tissue support during periods of muscle remodeling [8]. These muscle-related findings in animal models are frequently cited in the research literature as motivation for studying GHRH analog peptides in the context of sarcopenia (age-related muscle loss) and recovery from exercise-induced muscle damage.

Body Composition Research

Body composition findings in animal models consistently show reduced body fat percentage alongside maintained or increased lean mass under GHRH analog exposure. Visceral adipose tissue, the intra-abdominal fat depot associated with metabolic dysfunction in both rodent models and human populations, shows preferential reduction relative to subcutaneous fat in treated animals [8,10]. This visceral-selective lipolytic pattern is consistent with the known biology of GH-mediated fat mobilization, since visceral adipocytes express higher GH receptor density and are more responsive to GH-driven hormone-sensitive lipase activation than subcutaneous adipocytes. Long-term rodent studies have reported improved muscle-to-fat ratios in aging animals, providing a biological basis for research interest in GHRH analogs as potential tools for studying age-related changes in body composition.

Metabolic and Glucose Homeostasis Research

In diabetic and insulin-resistant animal models, GHRH analog exposure has produced improvements in glucose tolerance, enhanced insulin sensitivity measurements, and reduced fasting glucose concentrations [10]. Lipid panel changes have included reduced circulating triglycerides and favorable HDL ratios. These metabolic effects appear to be mediated through both direct GH receptor actions in peripheral tissues and indirect IGF-1 signaling. The timing of effects, emerging within two to four hours of administration and persisting despite peptide clearance, is consistent with the downstream GH-IGF-1 axis activation pattern discussed in the pharmacokinetics section. It is worth noting that growth hormone itself has complex and concentration-dependent effects on insulin sensitivity: acute GH elevation transiently impairs insulin-mediated glucose uptake in peripheral tissues, while the longer-term improvement in body composition (reduced visceral fat, increased lean mass) associated with sustained GH axis activation tends to improve insulin sensitivity overall. Research using CJC-1295 NO DAC in metabolic models must account for this biphasic relationship when interpreting glucose homeostasis findings.

Sleep and Recovery Research

Animal model studies examining sleep architecture under GHRH analog exposure have found increased slow-wave sleep duration and depth, enhanced GH pulse amplitude during natural sleep phases, improved recovery markers following exercise stress, and reduced post-exercise inflammatory markers [10]. The interaction between GHRH signaling and sleep regulation reflects a bidirectional neuroendocrine relationship: GHRH promotes non-REM sleep through hypothalamic mechanisms, and slow-wave sleep provides the optimal neurohormonal environment for maximal GH secretion. Timing of GHRH analog administration relative to natural sleep onset has been identified as a significant variable influencing GH pulse magnitude in these studies, with administration shortly before the expected sleep window producing larger and more sustained GH responses than administration at other circadian phases.

Aging Research

Aged rodent models show blunted GH pulse amplitude, reduced pulse frequency, and chronically low IGF-1 levels relative to young animals, a pattern that correlates with age-related declines in muscle mass, bone density, and physical performance. GHRH analog studies in aging animal models have found restoration of more youthful GH pulse patterns, improved physical performance metrics including grip strength and locomotor activity, and in some models improved cognitive function measurements [8,10]. These aging-focused preclinical findings have motivated research interest in GHRH analogs as tools for studying the hormonal biology of aging and sarcopenia, though translation of these animal model findings to human populations remains undemonstrated for CJC-1295 NO DAC specifically.

Clinical Trial Data

Available Human Data: CJC-1295 WITH DAC

No published human clinical trials have examined CJC-1295 NO DAC (Modified GRF 1-29) directly. The available human pharmacology data comes from the DAC version of the compound, studied by Teichman and colleagues in 2006 in healthy adult volunteers across a range of single doses (30 to 100 mcg/kg) administered by subcutaneous injection [2]. The DAC version’s extended half-life (5.8 to 8.1 days) produces fundamentally different pharmacokinetic behavior from the NO DAC formulation, so the human trial results cannot be applied directly to CJC-1295 NO DAC. However, the mechanistic pathway engaged (GHRHR activation, GH release, IGF-1 induction) is shared between both versions, and the DAC human trial findings provide important reference context. In the Teichman 2006 study, CJC-1295 WITH DAC produced dose-dependent increases in mean plasma GH concentrations and sustained IGF-1 elevations lasting up to 14 days after a single injection. GH pulse amplitude increased while pulse frequency was maintained, consistent with augmented pituitary somatotroph secretion rather than disruption of pulsatile release architecture. The compound was generally well tolerated in healthy adults, with the most common adverse effects being transient injection site reactions, headache, and flushing [2]. These findings established proof-of-concept for GHRH receptor agonism via this peptide class in humans.

Ionescu and Frohman (2006): Pulsatility Preservation

A clinically important mechanistic study by Ionescu and Frohman published in the Journal of Clinical Endocrinology and Metabolism examined whether pulsatile GH secretion is preserved under GHRH analog exposure [9]. The study found that the pulsatile architecture of GH release is maintained even during pharmacological GHRH receptor stimulation, supporting the research rationale for episodic GHRH analog administration. This finding underpins the distinction between the NO DAC formulation (which by design produces brief, discrete pituitary stimulation) and continuous GH infusion, which suppresses pulsatility and produces markedly different downstream metabolic and anabolic effects.

Evidence Gap for NO DAC Formulation

The specific absence of direct human trial data for CJC-1295 NO DAC is a significant limitation for the research field. Pharmacokinetic modeling and extrapolation from rodent data and from DAC-version human studies suggest that the NO DAC formulation produces discrete, short-duration GH pulses in humans, but this has not been directly measured in a controlled clinical trial setting. The fundamental questions of what GH pulse magnitude CJC-1295 NO DAC produces in healthy humans, how it varies with dose and circadian timing, and what the IGF-1 dose-response relationship looks like in human subjects remain unanswered in the published literature.

CJC-1295 NO DAC vs. CJC-1295 With DAC

The Drug Affinity Complex: What It Does

The Drug Affinity Complex (DAC) is a chemical modification added to one version of CJC-1295 that enables the peptide to form a covalent bond with lysine residues on circulating plasma albumin. Albumin is the most abundant protein in human plasma, with a half-life of approximately 19 days. By hitchhiking on albumin, CJC-1295 WITH DAC gains the carrier protein’s extended circulation time, transforming a peptide that would otherwise clear in minutes into one that persists in plasma for 5.8 to 8.1 days following a single dose [2]. This fundamentally changes the pharmacological profile: rather than producing a discrete pulsatile stimulus, CJC-1295 WITH DAC generates sustained, prolonged GHRHR activation throughout the week.

Comparative Pharmacological Profiles

The two formulations represent different research tools with different experimental applications:

Property	CJC-1295 NO DAC	CJC-1295 WITH DAC
Half-life	30 minutes to 2 hours	5.8 to 8.1 days
Albumin binding	None	Covalent via DAC
GH release pattern	Pulsatile, episodic	Sustained, prolonged
Dosing frequency in studies	Daily or twice daily	Weekly or biweekly
GHRHR desensitization risk	Lower (inter-dose receptor recovery)	Higher (sustained stimulation)
Circadian rhythm preservation	Better preserved	Partially disrupted
Human trial data	None directly available	Published Phase 1/2 data (Teichman 2006)
Primary research application	Physiological rhythm studies, receptor sensitivity research	Sustained GH elevation studies, GH deficiency models

Research Context for Each Formulation

CJC-1295 NO DAC is the appropriate research tool when the experimental question involves how pulsatile GHRH receptor stimulation affects downstream biology. Research protocols designed to study physiological GH axis behavior, receptor sensitivity maintenance over time, or the interaction between GHRH signaling and circadian hormone patterns use the NO DAC formulation for its closer approximation of endogenous GHRH biology [6,9]. CJC-1295 WITH DAC is appropriate for research questions requiring sustained, tonic GH axis elevation: for example, studying how continuous GHRHR stimulation over days affects body composition, bone density, or organ function in animal models. The once-weekly dosing in the human trial by Teichman and colleagues was enabled specifically by the DAC modification and would not be achievable with the NO DAC version at equivalent biological effect levels [2]. Neither formulation has been approved for any human therapeutic application.

Research Applications

Growth Hormone Deficiency Research

CJC-1295 NO DAC is used in laboratory research examining growth hormone deficiency states, both genetic models (such as GHRHKO mice) and pharmacologically induced deficiency models. The compound’s ability to restore pulsatile GH secretion in deficiency models makes it a useful tool for studying how growth hormone rhythm affects developmental outcomes, body composition, and organ growth, and for testing whether GHRHR agonism represents a viable approach to correcting deficiency states without bypassing endogenous pituitary regulation [8].

Body Composition and Lean Tissue Research

Animal model research examining how GHRH receptor stimulation influences the balance between lean mass and adipose tissue uses CJC-1295 NO DAC to generate pulsatile GH axis activation. Studies in this category examine the lipolytic effects of GH-mediated hormone-sensitive lipase activation in adipocytes, the anabolic effects of IGF-1 signaling on skeletal muscle protein synthesis, and the interaction between GH axis activity and body composition across different metabolic states [8,10]. This research has potential relevance to understanding the biology of sarcopenia, obesity, and aging-related body composition changes.

Muscle Biology and Recovery Research

Research into satellite cell biology, myofiber regeneration, and skeletal muscle protein turnover uses GHRH analog peptides as tools to modulate IGF-1 levels in a controlled, pulsatile manner. CJC-1295 NO DAC is applied in exercise recovery research models examining how GH axis activation influences repair of exercise-induced muscle damage, muscle fiber hypertrophy signaling, and contractile protein synthesis [8].

Metabolic Health Research

Research in insulin resistance, glucose homeostasis, and lipid metabolism uses CJC-1295 NO DAC to study how pulsatile GH axis activation interacts with metabolic pathways. Animal studies have examined effects on glucose tolerance, insulin sensitivity, and lipid panel markers under GHRH analog exposure, with findings suggesting potential relevance to research on metabolic syndrome and type 2 diabetes biology [10].

Aging Biology Research

The documented age-related decline in GH pulse amplitude and frequency in both rodents and humans makes GHRH analog research relevant to aging biology. CJC-1295 NO DAC is used in aged animal models to examine whether restoration of more youthful GH pulse patterns influences markers of biological aging, physical performance, cognitive function, and longevity-relevant endpoints [8,10].

Sleep and Circadian Biology Research

The intersection of GHRH signaling with sleep architecture and circadian hormone rhythms represents a distinct research application. CJC-1295 NO DAC is used in animal sleep studies to examine how GHRHR activation at different circadian phases affects slow-wave sleep depth, nocturnal GH pulse amplitude, and associated recovery processes [10].

Safety Profile and Tolerability

Data Sources and Limitations

Safety information specific to CJC-1295 NO DAC in human subjects does not exist in the peer-reviewed literature, as no direct human clinical trials have been published. The available safety data comes from the Teichman 2006 Phase 1/2 trial of CJC-1295 WITH DAC in healthy adults and from animal safety studies using GHRH analog peptides. Extrapolating these findings to the NO DAC formulation in humans involves uncertainty that researchers should acknowledge explicitly.

Findings from CJC-1295 WITH DAC Human Trial

In the Teichman 2006 study, CJC-1295 WITH DAC was generally well tolerated across a dose range of 30 to 100 mcg/kg in healthy adults [2]. The most commonly reported adverse effects were injection site reactions, including transient erythema, pain, and swelling at the subcutaneous administration site. Headache was reported by a subset of participants at higher doses. Facial flushing, particularly at higher dose levels, was observed in some participants. These vasodilatory effects are consistent with the known pharmacology of growth hormone and are expected to be transient given the short-duration GH pulses anticipated from pulsatile GHRH receptor stimulation. No serious adverse events were reported in the trial, and no clinically significant changes in safety laboratory parameters were observed during the follow-up period. Fluid retention, a known effect of elevated GH and IGF-1 levels, was not prominently reported in this single-dose study but represents a potential consideration in longer-exposure research protocols.

Pharmacology-Based Safety Considerations

Because CJC-1295 NO DAC acts through the endogenous GH axis rather than supplying exogenous GH, it operates within the body’s own feedback regulatory system. Somatostatin, released in response to elevated GH, acts at the pituitary to suppress further secretion, providing a self-limiting constraint on GH elevation. This feedback architecture distinguishes GHRH receptor agonists from exogenous GH administration, where no such feedback-mediated ceiling exists. However, pulsatile GHRH analog stimulation at doses exceeding physiological GHRH output can still drive GH elevations above the normal range, and the downstream consequences of such elevations, including IGF-1 elevation, potential fluid retention, changes in glucose metabolism, and joint or soft tissue discomfort, are consistent with known GH physiology [2,9]. Long-term safety data for CJC-1295 NO DAC at any dose in any species are not available in the published peer-reviewed literature. Researchers should design studies with appropriate monitoring of GH axis hormones, metabolic parameters, and any emerging adverse signals.

Regulatory and Legal Status

FDA Status

CJC-1295 NO DAC is not approved by the United States Food and Drug Administration for any human indication. It is classified as an investigational compound without approved clinical applications. In December 2024, the FDA’s Pharmacy Compounding Advisory Committee reviewed a nomination to include CJC-1295 on the 503A Bulks List, which would have allowed licensed compounding pharmacies to prepare CJC-1295 formulations for individualized patient prescriptions. The PCAC voted against this inclusion, citing insufficient clinical evidence to support compounding use under the 503A framework. This decision applies to compounding pharmacy contexts and does not affect the compound’s availability as a licensed research chemical for laboratory research purposes operating under appropriate institutional oversight.

WADA Status

CJC-1295 NO DAC is prohibited in sport under the World Anti-Doping Agency (WADA) Prohibited List, classified under Class S2 (Peptide Hormones, Growth Factors, Related Substances, and Mimetics). This prohibition applies both in-competition and out-of-competition, consistent with WADA’s treatment of growth hormone secretagogue peptides. Researchers working with athletes or in sports science contexts should be aware of this classification. The current WADA Prohibited List should be consulted annually, as classifications are updated each year.

International Research Classification

Outside the United States, regulatory classifications for CJC-1295 NO DAC vary by jurisdiction. In most countries it is classified as an unscheduled research compound without approved clinical indications, available for licensed laboratory research purposes. Researchers outside the United States should confirm local regulatory requirements before acquiring or using the compound. In no jurisdiction is CJC-1295 NO DAC approved for consumer use or self-administration outside of supervised clinical research protocols.

Research Use Context

CJC-1295 NO DAC is available as a research-grade lyophilized compound from licensed research chemical suppliers for use in approved laboratory research conducted under appropriate institutional oversight. Institutional review board approval or ethics committee authorization is required for any study involving human biological specimens, human participants, or investigational use outside of standard laboratory protocols. All use should be consistent with the research-only classification of this compound.

Research Limitations and Evidence Gaps

Absence of Direct Human Clinical Trial Data

The most significant limitation in the CJC-1295 NO DAC research literature is the complete absence of published human clinical trials examining the compound directly. Researchers working in this area must rely on two incomplete evidence sources: rodent pharmacokinetic and pharmacodynamic studies, which demonstrate expected mechanisms in animal systems but may not predict human responses accurately, and human trial data from the structurally different DAC formulation, which operates through the same receptor pathway but with fundamentally different kinetics that produce different patterns of receptor activation, GH secretion, and IGF-1 induction. The pharmacological extrapolation from CJC-1295 WITH DAC human data to CJC-1295 NO DAC expected human behavior is mechanistically reasonable but unvalidated [2,8]. Critical unanswered questions for human research include: what magnitude of GH pulse does CJC-1295 NO DAC produce in healthy adults at various doses; how does this pulse magnitude vary with body weight, sex, age, and baseline GH axis function; what is the IGF-1 dose-response relationship in humans; and what does the tolerability profile look like with repeated subcutaneous dosing over weeks or months?

Rodent-to-Human Translation Challenges

Rodent models of the GH axis differ from humans in several biologically important respects. Rats and mice secrete growth hormone in patterns that are more sexually dimorphic and higher in frequency than human GH secretion, with male rats showing strongly pulsatile patterns and female rats near-continuous secretion. The magnitude of GH responses to GHRH stimulation in rodents may not scale predictably to humans. Body composition effects observed in mouse models operated at doses relative to body weight that would not directly correspond to human dosing scenarios, and the knockout mouse models used in deficiency research represent extreme genetic states without clear human disease equivalents for most research applications [8].

Methodological Limitations in Preclinical Research

Published preclinical studies using CJC-1295 analogs frequently involve small group sizes, limited reporting of female animal data, and protocols designed to establish proof of mechanism rather than generate dose-response datasets. The most cited preclinical study (Alba et al., 2006) examined GHRH knockout mice, which represent a severe and genetically determined deficiency state rather than the age-related GH axis decline that motivates much of the research interest in this compound [8]. Whether findings from a genetic deficiency model predict effects in eugonadal, otherwise healthy animals or humans is not established. Standardized protocols across research groups do not exist for GHRH analog body composition and metabolism studies, limiting inter-study comparisons.

Long-Term Safety Data Gaps

No peer-reviewed study has examined the long-term safety of CJC-1295 NO DAC administration over months or years in any species in a published, indexed format. The consequence of chronically elevated IGF-1 levels, even within the physiological range, over extended periods is a meaningful research question particularly relevant to cancer biology, since IGF-1 receptor signaling promotes cell proliferation and survival. This concern applies broadly to all compounds that elevate IGF-1 levels through any mechanism, and it is not specifically supported or refuted by existing CJC-1295 NO DAC data because that data does not exist for long-term exposure scenarios [9].

Pulsatility Research Gaps

The mechanistic argument for CJC-1295 NO DAC over the DAC formulation centers on preservation of pulsatile GH secretion and avoidance of GHRHR desensitization, but this has not been tested in a head-to-head comparison study in humans. The Ionescu and Frohman (2006) study supporting pulsatility preservation under GHRH analog exposure used the DAC version, not the NO DAC formulation, meaning the specific pulsatility-preserving properties of the NO DAC approach in humans remain inferred from mechanism rather than directly measured [9]. Direct comparative human studies examining GH pulse architecture under each formulation have not been published.

Frequently Asked Questions

What is the difference between CJC-1295 NO DAC and regular CJC-1295?

The term “CJC-1295” is used to refer to two distinct compounds. CJC-1295 WITH DAC includes a Drug Affinity Complex modification that enables it to bind to plasma albumin, extending its half-life to nearly a week. CJC-1295 NO DAC (also called Modified GRF 1-29) lacks this modification and clears from the bloodstream within 30 minutes to two hours. The NO DAC version produces a brief, discrete pulse of growth hormone stimulation, while the DAC version maintains sustained stimulation for days after a single dose. Researchers choose between them based on whether the experiment requires pulsatile or sustained GH axis activation.

Why do researchers study pulsatile growth hormone release?

Natural growth hormone is not released at a constant rate. The body secretes it in discrete bursts, most prominently during deep sleep, with quiet intervals between pulses that allow pituitary receptor sensitivity to reset. Biological systems are calibrated to respond to this on-off pattern: the downstream effects on muscle, fat metabolism, and IGF-1 production depend on episodic GH stimulation rather than constant elevation. Research tools that replicate this pulsatile pattern are useful for studying how growth hormone rhythm affects biological outcomes and for understanding how disrupting that rhythm through continuous GH exposure produces different results.

Has CJC-1295 NO DAC been tested in humans?

CJC-1295 NO DAC has not been directly tested in a published human clinical trial. Available human data comes from studies of CJC-1295 WITH DAC, a pharmacologically related but kinetically different compound. The DAC version was studied in healthy adults in a Phase 1/2 trial published in 2006 and was generally well tolerated at the doses examined. Whether these findings apply to the NO DAC formulation is mechanistically plausible but has not been confirmed in human subjects research.

Is CJC-1295 NO DAC the same as a growth hormone injection?

No. CJC-1295 NO DAC does not contain growth hormone. It stimulates the pituitary gland to release the body’s own growth hormone by activating the same receptor that natural GHRH activates. Because this action works through the pituitary rather than bypassing it, the body’s natural feedback system (including somatostatin, which limits GH secretion) remains active. Exogenous GH injections deliver growth hormone directly into circulation, bypassing this feedback system entirely and producing fundamentally different kinetics and downstream effects.

Is CJC-1295 NO DAC prohibited in sport?

Yes. CJC-1295 NO DAC is prohibited under the WADA Prohibited List under Class S2, covering peptide hormones, growth factors, related substances, and mimetics. This prohibition applies both in-competition and out-of-competition. Athletes subject to WADA-governed anti-doping rules should not use this compound. Researchers should verify current WADA classification each year, as the list is updated annually.

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