CJC-1295

Background

CJC‑1295 is a synthetic, long‑acting growth hormone–releasing hormone (GHRH) analog designed to increase endogenous secretion of growth hormone (GH) and insulin‑like growth factor‑1 (IGF‑1).[7][3] It is structurally related to the 29–amino acid N‑terminal fragment of human GHRH (GRF 1‑29), but incorporates substitutions that increase resistance to dipeptidyl peptidase‑IV and other proteases, and a reactive maleimidopropionyl (MPA) moiety that forms covalent bonds with serum albumin.[7][3] These modifications confer a prolonged half‑life compared with native GHRH and earlier analogs such as sermorelin.[7]

CJC‑1295 was originally developed in the early 2000s as a depot‑like GHRH analog for indications where sustained GH elevation could be beneficial (e.g., lipodystrophy, age‑related GH decline), but clinical development did not progress to marketing authorization.[3] It is sometimes colloquially referred to in non‑regulated settings alongside “modified GRF (1‑29)”; however, in the scientific literature CJC‑1295 generally denotes the albumin‑binding, long‑acting GHRH analog, whereas “modified GRF (1‑29)” is more often used for shorter‑acting stabilized GHRH fragments lacking the albumin‑binding group.[3][4]

Mechanism of action

CJC‑1295 acts as an agonist at the GHRH receptor (GHRHR) on pituitary somatotroph cells.[7][3]

• Binding to GHRHR activates Gs protein–coupled signaling, increasing adenylyl cyclase activity and intracellular cAMP, which in turn promotes GH synthesis and pulsatile secretion.[7]
• The analog is designed to preserve physiologic pulsatility of GH by augmenting endogenous GHRH signaling rather than providing exogenous GH.[3]

Structural and pharmacokinetic features include:[7][3]

• Substitutions in the GHRH (1‑29) sequence that increase resistance to enzymatic degradation.
• An N‑terminal MPA group that forms covalent bonds with circulating albumin, creating a peptide–albumin conjugate with an extended systemic residence time.
• Resulting terminal half‑life in humans measured in days rather than minutes, allowing sustained elevation of IGF‑1 after single subcutaneous (SC) injection.[7]

Downstream effects reflect activation of the GH/IGF‑1 axis:[7][3]

• Increased pituitary GH release → elevated hepatic and peripheral IGF‑1 production.
• Modulation of serum proteins and metabolic pathways responsive to GH/IGF‑1, as demonstrated by proteomic changes one week after dosing in healthy volunteers.[7]

Evidence summary

The clinical evidence base for CJC‑1295 is limited and consists mainly of early‑phase studies in healthy adults, together with preclinical work. No large phase 3 trials or approved indications have been reported.[3][5]

Human studies

1. Activation of the GH/IGF‑1 axis and serum proteomics (Sackmann‑Sala et al.)

   • Design: Exploratory proteomic analysis using sera from a prior clinical study in 11 healthy young adult men before and one week after a single CJC‑1295 injection.[7]
   • Intervention: Single SC dose of CJC‑1295 (dose details in parent trial), with serum collected pre‑ and post‑dose.[7]
   • Outcomes: Marked and sustained increases in GH and IGF‑1 were confirmed from the parent pharmacokinetic/pharmacodynamic (PK/PD) study; proteomic profiling demonstrated significant changes in multiple serum proteins associated with GH activity and metabolism, supporting biologic engagement of the GH/IGF‑1 axis.[7]

2. Early GH secretagogue trials summarized in gerontology and men’s health reviews

   • A narrative gerontology review describes CJC‑1295 as a long‑acting GHRH analog that increases GH and IGF‑1 in adults, with effects persisting for up to one week after a single dose, but notes that data are restricted to small early‑phase trials with endocrine and PK/PD endpoints.[3]
   • A men’s health–focused review of peptide therapies similarly reports that CJC‑1295 increases IGF‑1 and GH levels in adults, but emphasizes the absence of robust randomized outcome trials, and that most clinical data remain unpublished or in small cohorts.[5]

3. Orthopaedic and sports medicine context

   • Reviews in sports and orthopaedics classify CJC‑1295 among growth hormone secretagogues being used off‑label for body composition and recovery, but emphasize that there are no controlled trials demonstrating benefits on musculoskeletal outcomes, performance, or injury recovery.[1][2][4]

Preclinical data

Preclinical studies (summarized in secondary reviews) indicate that long‑acting GHRH analogs like CJC‑1295 can:[3]

• Increase GH and IGF‑1 in animal models.
• Promote anabolic effects on lean mass and reduce adiposity in some settings.
• Show prolonged pharmacokinetics consistent with albumin binding.

However, peer‑reviewed preclinical datasets specifically naming CJC‑1295 are sparse in the public domain, and much of the development history appears in non‑public or proprietary reports.[3][5]

Overall, evidence is primarily biochemical (hormone levels, proteomic changes), with minimal data on clinical endpoints such as body composition, functional status, or long‑term safety.[3][5]

Clinical and research uses

Approved indications

• As of the latest available regulatory and literature data, CJC‑1295 has no approved therapeutic indication in the United States or European Union.[3][5][8]
• It is not listed among FDA‑approved peptide drugs in recent overviews of approved peptide therapeutics.[8]

Investigational and off‑label contexts

Documented or proposed investigational uses include:

• Age‑related GH decline / “adult GH insufficiency”: Early‑phase trials in healthy or older adults primarily evaluated endocrine responses rather than clinical outcomes.[3][7]
• Body composition and metabolic modulation: Reviews in gerontology and men’s health describe proposed use to improve lean mass and reduce fat mass; however, no controlled outcome trials have been published.[3][5]
• Sports and bodybuilding enhancement: CJC‑1295 is reported as a doping agent used for muscle growth, recovery, and fat loss, often combined with other secretagogues (e.g., ipamorelin), in regimens that differ substantially from researched dosing.[1][2][4]

World Anti‑Doping Agency (WADA) and sports medicine literature consider GHRH analogs including CJC‑1295 as prohibited performance‑enhancing substances.[4]

Given the lack of robust clinical trials, all clinical use of CJC‑1295 at present should be regarded as experimental or off‑label, often occurring outside formal regulatory oversight.[1][3][5]

Dosing context

Published human data provide only limited information on dosing, and this should not be interpreted as prescribing guidance.

• Early PK/PD studies in adults used single or intermittent SC injections of CJC‑1295 at doses sufficient to produce sustained elevations of IGF‑1 for up to one week.[7][3]
• Reviews summarizing these studies note that weekly or less‑frequent dosing is pharmacologically feasible due to the prolonged half‑life, in contrast to the multiple‑daily injections required for native GHRH.[3]

Sports and men’s health reviews describe non‑standard, frequently higher or stacked regimens used in unregulated settings (e.g., combined CJC‑1295 with GHRP/ghrelin analogs), but emphasize that such protocols lack safety and efficacy data and often diverge markedly from research doses.[1][4][5]

Because of the absence of approved indications and standardized regimens, no evidence‑based therapeutic dosing recommendations can be made at this time.

Safety profile

Systematic characterization of CJC‑1295 safety is limited due to the early‑phase nature and small size of available studies.[3][5] Reported and anticipated effects derive from:

• Short‑term human trials.
• Analogy to other GH‑axis therapies (e.g., GHRH analogs, GH).[3][5]
• Sports medicine and doping safety analyses.[1][4]

Adverse effects

Based on limited clinical reports and class effects of GH/IGF‑1 elevation, potential adverse effects include:[3][5]

• Injection‑site reactions: erythema, induration, or discomfort at the SC injection site.
• Edema and fluid retention: peripheral edema, arthralgia, and carpal tunnel–like symptoms are recognized GH‑axis adverse effects and may occur with potent GH secretagogues.[3][5]
• Metabolic effects: potential for insulin resistance, impaired glucose tolerance, and dyslipidemia with sustained GH/IGF‑1 elevation, extrapolated from GH therapy experience and doping literature.[3][4][5]
• Cardiovascular strain: increased blood pressure or cardiac workload has been raised as a theoretical risk with chronic supraphysiologic GH levels.[4]
• Neoplastic risk: long‑term stimulation of the GH/IGF‑1 axis raises concerns about promotion of existing malignancies, by analogy with GH therapy; direct long‑term data for CJC‑1295 are lacking.[3][5]

Sports‑oriented reviews also highlight psychiatric symptoms, polypharmacy interactions, and product quality issues (contamination, mislabeling) with peptide use in unregulated markets, though these are not specific to CJC‑1295.[1][4]

Contraindications and precautions (theoretical / class‑based)

Formal contraindication labeling does not exist because the drug is not approved. From class effects and expert reviews, situations of concern include:[3][4][5]

• Known active malignancy or history of cancer with high IGF‑1 sensitivity.
• Uncontrolled diabetes mellitus or significant insulin resistance.
• Severe cardiovascular disease, uncontrolled hypertension, or proliferative retinopathy.
• Pregnancy and lactation, given absence of safety data.

Use in children was generally excluded from adult peptide therapy reviews due to distinct risk–benefit considerations and the availability of established pediatric GH therapies.[5]

Data gaps

• No long‑term (>12 months) controlled safety data in any indication.
• Limited information on immunogenicity, antibody formation, or rare adverse events.
• No systematic pharmacovigilance data, as the compound has not entered routine clinical use.[3][5]

Regulatory status

• United States (FDA): CJC‑1295 does not appear on lists of FDA‑approved peptide drugs and has no FDA‑approved indication.[8] There are no publicly registered phase 3 trials or product labels for CJC‑1295 in U.S. regulatory databases.[3][8]
• European Union (EMA): No centralized marketing authorization or EMA‑approved product information for CJC‑1295 has been reported in recent peptide therapeutics reviews.[8]
• Doping and sports regulation: GHRH analogs including CJC‑1295 are classified under prohibited substances in sports, with detection methods and enforcement discussed in anti‑doping and sports medicine literature.[4]

Consequently, any current human use of CJC‑1295 occurs in the context of research studies, unregulated compounding, or off‑label “peptide therapy” practices, rather than within an approved medicinal product framework.[1][3][5] Clinicians are advised in recent reviews to counsel patients about the experimental nature, limited evidence base, and potential risks associated with such peptides.[1][3][5]