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Single Peptide

CJC-1295

Overview

CJC-1295 is a synthetic analogue of growth hormone-releasing hormone (GHRH). It is built on the first 29 amino acids of human GHRH — the shortest fragment that retains full biological activity at the GHRH receptor — with four amino acid substitutions that protect it from enzymatic breakdown, and, in the original form, a chemical linker that binds it to circulating albumin so that it persists in the blood for days rather than minutes.

The most important thing to understand about CJC-1295 is that the name is used for two different molecules. CJC-1295 with DAC carries the drug affinity complex — a maleimidopropionic acid group that forms a covalent bond with cysteine-34 of serum albumin after injection — and has a circulating half-life measured in days. CJC-1295 without DAC, more accurately called modified GRF(1-29), is the same tetrasubstituted peptide backbone without the albumin linker, and clears in minutes. The published human pharmacology is on the DAC form. The two are not interchangeable, and dosing figures cannot be read across from one to the other.

CJC-1295 was developed by ConjuChem Biotechnologies in the early 2000s. Two human studies in healthy adults were published in 2006, both in the Journal of Clinical Endocrinology & Metabolism, establishing pharmacokinetics, growth hormone and IGF-1 responses, and the observation that the natural pulsatile rhythm of GH secretion survives continuous receptor stimulation. Clinical development did not continue to registration, and CJC-1295 has never been approved by any regulator for any indication.

It is prohibited in sport. The World Anti-Doping Agency lists growth hormone-releasing factors, including GHRH analogues and their fragments, under section S2 of the Prohibited List — banned at all times, in and out of competition.

Dosage & Reconstitution

Vial strength
5 mg
BAC water added
2 mL
Final concentration
2.5 mg/mL
WeeksDosageSyringe units (U-100)
Weeks 1–20.3 mg12 units0.12 mL
Weeks 3–40.5 mg20 units0.2 mL
Weeks 5–60.75 mg30 units0.3 mL
Weeks 7–121 mg40 units0.4 mL

FrequencyTwice weekly, subcutaneous.

Note

For review — not the design of the cited study. Teichman et al. (2006) gave single ascending doses of 0.03 to 0.06 mg per kilogram of body weight of the DAC form to healthy adults, with weekly repeat dosing in one arm; the fixed-milligram twice-weekly titration in the chart is a circulated research protocol, not that study. The concentration strip above the chart is calculated from the vial and water volume and is correct.

Which form the vial contains changes this entirely, and the note that follows sets out why.

Everything charted here depends on which CJC-1295 the vial holds. The published human work cited below is on the DAC form, whose drug-affinity complex gives it a half-life measured in days; the modified GRF(1-29) fragment sold without DAC clears in minutes, has no human dose-ranging study of its own, and is dosed on a different rhythm entirely, so these rows should not be read across to it. Amounts are per injection rather than per day because the schedule is twice weekly, and they are body-weight-independent figures where the cited study dosed by kilogram — that substitution is the reason the chart is flagged. Athena supplies CJC-1295 only inside the 1:1 CJC-1295 + ipamorelin blend, whose vial holds 5 mg of it, so 5 mg is the strength charted here. Made up with 2 mL that is 2.5 mg/mL, which puts the 0.3 mg first step at 12 units and the 1 mg maintenance amount at 40 units, both inside one 50-unit syringe.

What this evidence establishes. The published human data covers CJC-1295 with DAC (the long-acting drug-affinity-complex form). The modified GRF(1-29) fragment sold without DAC has a half-life measured in minutes rather than days and has no published human dose-ranging study of its own, so the figures below should not be read across to it. Which form a vial contains changes the answer entirely.

Sources: Teichman et al., JCEM 2006 — safety, PK and PD of CJC-1295 in healthy adults

For educational and laboratory research purposes only. It does not provide medical advice, dosing recommendations, or instructions for human or veterinary use. Syringe units assume a U-100 syringe, on which 1 mL is 100 units and a 50-unit syringe holds 0.5 mL.

Mechanism of Action

CJC-1295 acts one step upstream of growth hormone itself. Rather than supplying GH, it stimulates the pituitary's own somatotroph cells to release it, which leaves the physiological feedback loops — somatostatin restraint, IGF-1 negative feedback — structurally intact.

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GHRH Receptor Agonist

Binds the GHRH receptor on anterior pituitary somatotrophs, the same receptor the body's own GHRH uses, triggering GH synthesis and release.

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Four Substitutions

D-Ala at position 2, Gln at 8, Ala at 15 and Leu at 27 protect the peptide from dipeptidyl peptidase-4 and other proteases that degrade native GHRH within minutes.

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The Drug Affinity Complex

A maleimidopropionic acid linker reacts with cysteine-34 on serum albumin after injection, forming a covalent bioconjugate. Albumin's long residence time in circulation becomes the peptide's own.

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Days, Not Minutes

Teichman and colleagues measured a terminal half-life of roughly 6 to 8 days for the DAC form in healthy adults. Native GHRH is cleared in single-digit minutes.

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Pulsatility Preserved

Ionescu and Frohman showed that GH release remained pulsatile during continuous CJC-1295 stimulation. The peptide raises the amplitude of pulses rather than flattening secretion into a plateau.

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Feedback Intact

Because the signal enters at the pituitary rather than bypassing it, somatostatin tone and IGF-1 negative feedback still operate — a mechanistic difference from exogenous recombinant GH, not a demonstrated safety advantage.

Why the DAC distinction matters

Every published human pharmacokinetic and pharmacodynamic figure for CJC-1295 was generated with the DAC form. The modified GRF(1-29) fragment sold without DAC has the same receptor pharmacology but a completely different exposure profile: a short pulse of receptor activation rather than a sustained elevation over days. It has no human dose-ranging study of its own. Any statement about duration, frequency or IGF-1 response that is true of the DAC form is not automatically true of the fragment, and a vial labelled simply "CJC-1295" does not tell you which one it contains.

Research Timeline

1982
GHRH Isolated
Human growth hormone-releasing hormone is characterised, and GHRH(1-29) is identified as the shortest fully active fragment. Every GHRH analogue since, including CJC-1295 and the approved drug tesamorelin, descends from this fragment.
2005
Albumin Bioconjugate Concept Demonstrated
Jetté and colleagues publish in Endocrinology that hGRF(1-29)-albumin bioconjugates activate the GRF receptor on the rat anterior pituitary. This is the preclinical proof that attaching a GHRH fragment to albumin preserves receptor activity while extending exposure.
2006
First Human Pharmacology — Teichman et al.
A randomised, double-blind, placebo-controlled trial of single ascending doses in healthy adults, published in JCEM. Doses of 30 and 60 micrograms per kilogram produced sustained increases in GH and IGF-1, with a terminal half-life of approximately 6 to 8 days. Reported adverse events were predominantly transient injection-site reactions and flushing.
2006
Pulsatility Study — Ionescu & Frohman
Also in JCEM: frequent blood sampling during continuous CJC-1295 exposure showed that GH secretion remained pulsatile, with pulse amplitude rather than pulse frequency accounting for the increase. This is the mechanistic observation most often cited for CJC-1295 and the one that distinguishes it from continuous GH administration.
Late 2000s
Clinical Development Ends
Development by the sponsor did not proceed to registration. No Phase 3 programme was completed and no regulatory approval was ever granted. Publicly available peer-reviewed human data for CJC-1295 remains essentially the two 2006 papers.
Present
Grey-Market Circulation and Review Literature
CJC-1295 circulates widely as a research chemical, frequently blended 1:1 with ipamorelin. Recent narrative reviews of performance-enhancing peptides in the endocrinology and sports medicine literature describe exactly this pattern: substantial informal use resting on a very small formal evidence base.

Research limitations

The human evidence for CJC-1295 is two single-centre pharmacology studies in healthy volunteers, published in the same year by investigators connected to the developer, using surrogate endpoints — GH concentration, IGF-1 concentration, half-life. Those are the right endpoints for a Phase 1 pharmacology study and the wrong ones for any claim about a clinical outcome. No trial has measured body composition, muscle strength, bone density, sleep quality, recovery, injury healing or any patient-reported outcome. No trial has run longer than the observation window needed to characterise a single dose.

Long-term safety is unstudied. Chronic elevation of the GH/IGF-1 axis is a legitimate area of concern — IGF-1 concentrations at the upper end of the normal range are associated with increased risk of several common cancers in observational meta-analysis — and no CJC-1295 study was designed or powered to detect anything of that kind. Nothing here demonstrates harm from CJC-1295; the point is that the studies that could detect it have not been done.

Contraindications & Safety Data

CJC-1295 has no approved label and therefore no regulator-reviewed contraindication list. What follows is drawn from GHRH-analogue class pharmacology and from the labelled contraindications of tesamorelin, the one approved GHRH analogue, where the mechanism is shared.

Condition / FactorRisk LevelRationale
Active malignancyCONTRAINDICATEDRaising GH and IGF-1 in the presence of active cancer is contraindicated across the GHRH-analogue class. IGF-1 is mitogenic and anti-apoptotic; the approved GHRH analogue carries this contraindication on its label.
Pituitary tumour or prior hypothalamic-pituitary irradiation or surgeryCONTRAINDICATEDClass contraindication for GHRH analogues. The drug acts directly on pituitary somatotrophs.
PregnancyCONTRAINDICATEDClass contraindication. No reproductive safety data exist for CJC-1295.
Diabetes or impaired glucose toleranceHIGH CAUTIONGrowth hormone antagonises insulin action. Glucose intolerance is a recognised effect of GH-axis stimulation and is monitored on the approved analogue's label.
Elevated baseline IGF-1HIGH CAUTIONHigher circulating IGF-1 is associated in meta-analysis with increased risk of certain common cancers. Adding sustained stimulation on top of an already-high baseline compounds an unquantified risk.
Unknown DAC status of the materialMODERATEThe two forms differ in half-life by orders of magnitude. Applying a DAC-form schedule to the fragment, or the reverse, produces an exposure profile no study has characterised.
Injection-site and vasomotor reactionsCOMMON, MILDTransient injection-site reactions and flushing were the predominant adverse events in the published single-dose human study.
Competitive athletesPROHIBITEDGrowth hormone-releasing factors including GHRH analogues are prohibited at all times under WADA Prohibited List section S2.

Regulatory Status

FDA: CJC-1295 is not approved for any indication in the United States and has no marketing authorisation anywhere. It is not a compounding-eligible substance and has been the subject of FDA attention as an unapproved drug marketed under research-chemical labelling.

WADA: prohibited at all times, in and out of competition, under section S2 (Peptide Hormones, Growth Factors, Related Substances and Mimetics), which explicitly covers growth hormone-releasing hormone and its analogues.

Approved alternative in the class: tesamorelin is an FDA-approved GHRH analogue with a completed Phase 3 programme, a label, a defined indication and post-marketing surveillance. It exists as a point of comparison: the difference between CJC-1295 and tesamorelin is not chemistry but evidence.

References (APA 7th Edition)

Teichman, S. L., Neale, A., Lawrence, B., Gagnon, C., Castaigne, J.-P., & Frohman, L. A. (2006). 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. The Journal of Clinical Endocrinology & Metabolism, 91(3), 799–805. https://doi.org/10.1210/jc.2005-1536
Ionescu, M., & Frohman, L. A. (2006). Pulsatile secretion of growth hormone (GH) persists during continuous stimulation by CJC-1295, a long-acting GH-releasing hormone analog. The Journal of Clinical Endocrinology & Metabolism, 91(12), 4792–4797. https://doi.org/10.1210/jc.2006-1702
Jetté, L., Léger, R., Thibaudeau, K., Benquet, C., Robitaille, M., Pellerin, I., Paradis, V., van Wyk, P., Pham, K., & Bridon, D. P. (2005). 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. Endocrinology, 146(7), 3052–3058. https://doi.org/10.1210/en.2004-1286
Renehan, A. G., Zwahlen, M., Minder, C., O'Dwyer, S. T., Shalet, S. M., & Egger, M. (2004). Insulin-like growth factor (IGF)-I, IGF binding protein-3, and cancer risk: Systematic review and meta-regression analysis. The Lancet, 363(9418), 1346–1353. https://doi.org/10.1016/S0140-6736(04)16044-3
Dominikowski, A., et al. (2026). The emerging landscape of performance-enhancing peptides modulating the GH-IGF1 axis: Bridging the gap between clinical evidence and practice. Frontiers in Endocrinology, 17, 1822475.
World Anti-Doping Agency. (2025). The World Anti-Doping Code International Standard: Prohibited List. WADA.

CJC-1295 Research Readiness Quiz

Test your understanding of the DAC distinction, what the two 2006 human studies actually measured, and where the evidence ends.

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Educational Disclaimer

This profile is for educational and research purposes only. It is not medical advice, and nothing on it is a protocol, a recommendation, or an instruction for use in a person or an animal.

Athena Peptides Education does not prescribe, sell, or recommend any compound. Compounds discussed here are for laboratory research only and are not for human consumption. Always consult a qualified physician before making any decision about your health.