Level IIb · Human DataGHRH AgonistGH Axis HubDAC Extended-Release
CJC-1295
Long-Acting GHRH Analog with Drug Affinity Complex · GH Axis Stimulant · Pulsatility-Preserving
6–8dt½ with DAC
1.5–3×IGF-1 Elevation
n=65Phase I/II Subjects
PulsatileGH Profile
IIb
Evidence Level IIb — Phase I/II Human Pharmacodynamic Data
CJC-1295 (with DAC) has published human pharmacodynamic data from a Phase I/II dose-ranging trial (Teichman et al. 2006, JCEM, PMID 16352683; n=65 healthy adults). This is the highest evidence level in the Metabolic Hub outside of Tesamorelin (Level I, FDA-approved). Key caveat: the trial used IGF-1 and GH area-under-curve as primary endpoints — both surrogate markers. No Phase III trial with functional or clinical outcome endpoints has been published. ConjuChem Technologies discontinued development after Phase II. Evidence Level IIb reflects positive human pharmacodynamic proof-of-concept without functional efficacy confirmation.
Critical Disambiguation: Two Different Compounds
CJC-1295 with DAC vs. CJC-1295 without DAC (Mod-GRF 1-29)
The single most common clinical error surrounding CJC-1295 is conflating two distinct compounds that share part of a name but differ fundamentally in pharmacokinetics, dosing requirements, and evidence base. When a patient or clinician says "CJC-1295," clarifying which formulation is essential before any discussion of dosing or efficacy proceeds.
GH profilePulsatile bolus, rapid return to baseline
CombinationAlmost always combined with Ipamorelin
Why the Naming Confusion Exists: "CJC-1295" refers to the patented compound with the Drug Affinity Complex developed by ConjuChem Technologies. "CJC-1295 without DAC" is a misnomer used in the compounding market for Modified GRF (1-29) — the same GHRH(1-29) backbone without the albumin-binding linker. The two peptides have the same receptor target but entirely different pharmacokinetic profiles. The Teichman 2006 human trial data applies ONLY to CJC-1295 with DAC. Applying that trial's evidence to Mod-GRF is not scientifically defensible. This profile covers CJC-1295 with DAC (the compound with human data) as the primary subject; the Mod-GRF combination protocol is addressed in the dosing and ipamorelin sections.
CJC-1295 is built on the N-terminal 1-29 fragment of human GHRH — the shortest sequence retaining full GHRHR agonism. Four amino acid substitutions stabilize the peptide against enzymatic degradation, and the Drug Affinity Complex (DAC) linker at a C-terminal lysine provides albumin-binding that extends systemic half-life by ~150-fold vs. native GHRH.
Human GHRH(1-29) vs. Mod-GRF vs. CJC-1295 with DAC — Key Positions
D-amino acid substitution prevents dipeptidyl peptidase IV (DPP-IV) cleavage at Tyr¹-Ala² — the primary site of in vivo GHRH degradation. Extends biological activity from minutes to hours even without DAC.
8
Asn
Gln
Stability
Asparagine (Asn) is susceptible to spontaneous deamidation under physiological pH — deamidation converts Asn to Asp, altering the peptide's charge and potentially receptor affinity. Glutamine (Gln) is identical in structure but lacks the deamidation-prone amide linkage.
15
Gly
Ala
Stability
Glycine's conformational flexibility at position 15 makes it a susceptibility point for certain endopeptidases. Alanine introduces a side-chain methyl group that restricts backbone flexibility and reduces enzymatic susceptibility without significantly altering receptor binding geometry.
27
Met
Leu
Stability
Methionine is oxidation-prone — the sulfur side chain oxidizes to methionine sulfoxide under ambient conditions and in vivo, altering hydrophobicity and potentially reducing receptor affinity. Leucine provides equivalent hydrophobic character without oxidative vulnerability.
C-term +1
—
Lys-DAC linker
DAC Site
CJC-1295 only (not Mod-GRF). A lysine residue is added at the C-terminus and conjugated to a maleimide-C8-PEG2-NHS ester linker. After SC injection, the maleimide reacts with the Cys34 thiol of serum albumin, forming a stable (reversible) covalent thioether bond. The albumin acts as a circulating depot for CJC-1295, extending t½ from ~30 min to 6–8 days.
Molecular Weight — Mod-GRF (1-29)
~3,367 Da
29 amino acids, four stability substitutions, no DAC linker. MW used for HED calculations from rodent GHRH studies.
Molecular Weight — CJC-1295 DAC
~3,636 Da
Same backbone plus C-terminal lysine and DAC linker (adds ~269 Da). Once albumin-bound, the complex is ~67,000+ Da — the size of albumin itself.
Target Receptor
GHRHR
Growth hormone-releasing hormone receptor on anterior pituitary somatotrophs. Same receptor as endogenous GHRH(1-44); the 1-29 fragment retains full agonist activity.
Half-Life Comparison
150× Extension
Native GHRH: t½ ~7 min IV. Mod-GRF: t½ ~20–30 min SC. CJC-1295 with DAC: t½ ~6–8 days SC. The DAC linker achieves a ~150-fold extension of functional half-life.
CJC-1295 acts through a well-characterized receptor (GHRHR) on a well-understood pathway (GH/IGF-1 axis). This mechanistic clarity distinguishes it from Level V compounds like BPC-157 whose receptors remain poorly characterized. The GH/IGF-1 axis is one of the most-studied endocrine systems in medicine, providing a robust preclinical-to-clinical translational framework.
Step 1 — DAC
Albumin Depot Formation
After SC injection, the DAC maleimide linker reacts with Cys34 of serum albumin within minutes. The CJC-1295/albumin complex circulates in plasma, with the peptide slowly dissociating from albumin and becoming available for receptor binding over 6–8 days.
Step 2 — Receptor
GHRHR Activation
Free CJC-1295 (dissociated from albumin) reaches the anterior pituitary and binds GHRHR — a Gαs-coupled GPCR. Receptor activation stimulates adenylyl cyclase → cAMP rise → PKA activation → somatotroph depolarization and GH vesicle release.
Step 3 — GH Release
Pulsatile GH Secretion
The sustained GHRHR stimulation does not produce flat-line GH — crucially, endogenous somatostatin tone (from hypothalamus) continues to cycle, creating GH pulses on an elevated baseline. Teichman 2006 documented maintained pulsatility over 7+ days, distinguishing CJC-1295 from exogenous hGH administration.
Step 4 — Liver
Hepatic IGF-1 Induction
GH binds hepatic GH receptors → activates JAK2/STAT5b signaling → transcriptional upregulation of IGF-1 gene (Igf1). Liver is the dominant source of circulating IGF-1 (~70–80%). IGF-1 elevation in Teichman 2006: 1.5–3× above baseline, sustained 9–11 days after single injection.
Step 5 — Peripheral
IGF-1 Tissue Effects
IGF-1 binds IGF-1R on skeletal muscle (protein synthesis, satellite cell activation), adipose tissue (lipolysis via HSL upregulation), bone (osteoblast stimulation, collagen synthesis), and connective tissue (fibroblast proliferation). Local autocrine/paracrine IGF-1 production at peripheral tissues adds to hepatic IGF-1.
Step 6 — Feedback
Somatostatin Counterregulation
Rising IGF-1 and GH provide negative feedback to the hypothalamus → increased somatostatin release → periodic GH pulse suppression. This feedback loop is preserved with CJC-1295 (unlike exogenous GH, which overrides the axis entirely), preventing receptor desensitization that might occur with sustained non-pulsatile stimulation.
DAC (Drug Affinity Complex) — Albumin Binding Mechanism in 4 Steps
①
SC injection of CJC-1295 DAC. Maleimide group is reactive but stable in the vial (lyophilized, near-neutral pH). Upon injection into subcutaneous tissue, the maleimide encounters albumin in interstitial fluid and capillaries.
②
Michael addition: maleimide + Cys34-SH of albumin → stable thioether bond. Cys34 is the only free thiol on albumin and is accessible in the native conformation. Reaction is selective and rapid (minutes to hours).
③
CJC-1295/albumin complex circulates in plasma. The complex (MW ~67,000+ Da) avoids renal filtration (cutoff ~60,000 Da) and resists proteolysis. Albumin's ~19-day half-life acts as a long-lived peptide vehicle.
④
Slow dissociation: the CJC-1295/albumin bond hydrolyzes gradually under physiological conditions, releasing free active peptide into circulation over 6–8 days. Free CJC-1295 then reaches GHRHR on pituitary somatotrophs.
CJC-1295 with DAC is one of the very few compounding-market research peptides with published human pharmacodynamic data from a randomized clinical trial. This is a meaningful distinction from Level V compounds — there is human evidence. The critical caveat is that IGF-1 elevation and GH AUC are surrogate endpoints, not clinical outcomes. No trial has demonstrated that CJC-1295-induced IGF-1 elevation translates into measurable improvements in muscle mass, fat loss, or other functional endpoints in humans.
Prolonged Stimulation of GH and IGF-1 Secretion by CJC-1295 — Primary Human Evidence
Level IIb
Design: Randomized, double-blind, placebo-controlled dose-ranging Phase I/II study. CJC-1295 with DAC administered as single SC or IV injection across multiple dose cohorts.
Population: n=65 healthy adults (males and females). Age range not fully specified in published data; subjects with normal baseline GH axis function.
Doses tested: 30, 60, 90, 120 mcg/kg SC and IV; additional cohorts at higher doses in the full data set. Primary analysis focused on SC route.
GH response: GH area-under-curve increased 2–10× above baseline in dose-dependent fashion. GH secretion maintained characteristic pulsatile pattern throughout the observation period — not blunted to flat-line.
IGF-1 response: Serum IGF-1 elevated 1.5–3.0× above individual baseline. Duration: IGF-1 remained elevated for 9–11 days after a single injection — the longest sustained IGF-1 elevation documented for any synthetic GHRH analog in a published human trial.
Dose-response: Clear dose-dependent relationship between CJC-1295 dose (mcg/kg) and both GH AUC and peak IGF-1 elevation. Plateau effect appeared at higher doses consistent with receptor saturation or somatostatin counterregulation.
Safety: No serious adverse events. Adverse effects observed: mild-to-moderate injection site reactions (most common), facial flushing (transient, minutes after injection — likely NO-mediated vasodilation), headache (small number of subjects), nausea (rare). No evidence of organ toxicity. Antibody assessment: low-titer anti-CJC-1295 antibodies detected in a subset of subjects; neutralizing effect not clearly demonstrated within the trial duration.
Pulsatility confirmation: Serial GH sampling demonstrated that the high-frequency GH pulse pattern was maintained, not replaced by a flat-line elevation — a key mechanistic claim confirmed in human subjects for the first time for a long-acting GHRH analog.
Evidence Limitations — What the Teichman 2006 Trial Did and Did Not Show
Surrogate endpoints only: IGF-1 and GH-AUC are pharmacodynamic markers, not clinical outcomes. The trial demonstrated that CJC-1295 raises IGF-1 — it did not demonstrate that this IGF-1 elevation produces measurable improvements in body composition, muscle mass, strength, or any patient-relevant outcome in humans.
No placebo-controlled functional outcome data: No published RCT has compared CJC-1295 vs. placebo on DXA-measured body composition, VO2max, bone density, or any other functional endpoint in human subjects.
Short observation window: The trial characterized single-injection PK/PD; it did not examine repeated dosing over months (the typical clinical research context) or long-term effects on pituitary function or IGF-1 receptor regulation.
Development discontinued: ConjuChem Technologies restructured after Phase II. No pharmaceutical sponsor has advanced CJC-1295 to Phase III. This creates a permanent Level IIb ceiling for this specific compound unless a new sponsor emerges.
Dose translation uncertainty: Trial doses (30–120 mcg/kg) translate to 2,100–8,400 mcg for a 70 kg adult per single injection. Clinician-reported doses (typically 1–2 mg/week) are substantially below even the lowest trial dose on a per-injection basis, though frequency differs.
Endogenous GH is secreted in discrete pulses — approximately 6–12 per 24 hours in healthy adults, with the largest pulse occurring in early slow-wave sleep. These pulses are not merely a delivery mechanism; they are pharmacologically meaningful. GH receptor sensitivity is higher during peak-to-trough cycling than under continuous exposure, and physiological pulsatility is associated with better anabolic-to-metabolic response ratios. Understanding this shapes the clinical comparison between CJC-1295 and exogenous hGH.
Schematic GH Profile: CJC-1295 with DAC vs. Exogenous hGH (Illustrative — Not to Scale)
CJC-1295 DAC — elevated pulsatile GH profile over 6 days
Exogenous hGH — single sharp peak, returns near baseline
CJC-1295 with DAC
Physiological Pattern
Pulsatile GH secretion maintained — somatostatin oscillations continue to cycle normally, creating pulse amplitude on top of elevated baseline
GH receptor recycling preserved — receptor downregulation is minimized by peak/trough cycling, maintaining downstream sensitivity
IGF-1 elevation is GH-axis-mediated — hepatic IGF-1 responds to pulsatile stimulation, which is the physiological signal pathway
Once weekly dosing — the DAC depot maintains the effect between doses; no daily injection required
Exogenous hGH
Non-Physiological Pattern
Flat-line IGF-1 elevation — daily subcutaneous hGH produces sustained non-pulsatile IGF-1 elevation; this pattern does not occur physiologically
GH axis suppression — exogenous GH inhibits endogenous GH secretion via negative feedback; pituitary somatotrophs become quiescent with prolonged use
Higher supraphysiological risk — direct GH supplementation bypasses pituitary regulatory control; doses are harder to titrate to physiological range
FDA Schedule II status — synthetic hGH (somatropin) is an FDA-approved drug for specific indications (GHD, HIV wasting, Prader-Willi); unapproved use is a Schedule II violation
Daily injection required — standard protocol is once-daily SC injection, often timed to evening to mimic endogenous GH rhythm
The CJC-1295 / Ipamorelin combination is the most frequently prescribed peptide pairing in clinical peptide medicine. The two agents act through different receptors on the same cell population (somatotrophs) to produce GH release that is larger than either agent alone — not merely additive but mechanistically synergistic. This section covers the Mod-GRF 1-29 + Ipamorelin protocol (the most common formulation) alongside the CJC-1295 DAC option.
Binds GHS-R1a (ghrelin receptor) → Gαq → PLC → IP3 → intracellular Ca²⁺ release → GH vesicle exocytosis from same somatotroph population
Increases GH pulse frequency (number of pulses) in addition to amplitude
Independently suppresses somatostatin release from hypothalamus — "opening the gate" for GHRH-stimulated pulses
Highly GH-selective — minimal cortisol or prolactin elevation vs. older GHRPs (GHRP-6, GHRP-2)
Why the Combination Produces Synergistic GH Release
Dual intracellular signaling: GHRHR (Gαs/cAMP) and GHS-R1a (Gαq/IP3/Ca²⁺) converge on GH vesicle exocytosis through separate second messenger pathways. Both must occur simultaneously for maximal GH release — the combination fires both triggers at once.
Somatostatin suppression: Ipamorelin reduces somatostatin release from hypothalamic neurons, which GHRH cannot do alone. Lower somatostatin tone allows a larger net GH response to GHRH stimulation — removing the brake while the GHRH accelerator is pressed.
Amplitude + frequency: GHRH primarily amplifies GH pulse magnitude; GHRPs primarily increase GH pulse frequency. Combining them increases both parameters simultaneously, resulting in greater total GH AUC per day than either alone.
Human evidence for Ipamorelin separately: Raun et al. (1998, Eur J Endocrinol) published Phase I human pharmacokinetic and pharmacodynamic data for Ipamorelin, establishing its human GH-stimulating profile and favorable safety data relative to GHRP-6. The combination with CJC-1295/Mod-GRF has not been studied in a published human RCT — the synergy rationale is mechanistic, not empirically confirmed in humans.
Mod-GRF + Ipamorelin vs. CJC-1295 DAC + Ipamorelin — Key Difference: Mod-GRF (without DAC) + Ipamorelin is designed for pulsatile bolus dosing (2–4× daily, or pre-sleep), creating discrete GH pulses that mimic the physiological pattern. CJC-1295 with DAC provides a sustained elevated GH baseline over days — adding Ipamorelin to this produces a different pharmacodynamic profile (elevated baseline + additional acute pulses on dosing days). Both approaches have clinical rationale but serve different goals: the Mod-GRF approach prioritizes GH pulse fidelity; the DAC approach prioritizes convenience and sustained IGF-1 elevation.
CJC-1295 with DAC is supplied as a lyophilized (freeze-dried) powder and must be reconstituted before use. The DAC linker's reactive maleimide group is the pharmacological engine of the compound — without an intact maleimide, CJC-1295 DAC cannot bind albumin and reverts to a short-acting Mod-GRF-like profile. Reconstitution conditions, diluent choice, and cold chain management directly determine whether the compound performs as the Teichman 2006 trial data suggests.
Reconstitution Diluent
Bacteriostatic Water
0.9% benzyl alcohol in sterile water (BW) is the standard diluent. The benzyl alcohol preservative extends the reconstituted peptide's shelf life vs. plain sterile water by inhibiting microbial growth in multi-dose vials. Sterile water for injection (SWFI) may be used for single-use reconstitution. Avoid acetic acid solutions used for some peptides — the DAC maleimide is sensitive to pH extremes.
Storage — Lyophilized
−20°C Preferred
Lyophilized CJC-1295 DAC is stable at 2–8°C (refrigerator) for several months if kept sealed and away from light. Longer-term storage at −20°C minimizes degradation. Critical: protect from moisture — lyophilized peptides absorb atmospheric water (hygroscopic), which can initiate hydrolysis of the DAC maleimide group. Keep the vial sealed until reconstitution.
Storage — Reconstituted
2–8°C, ≤28 Days
Reconstituted CJC-1295 DAC in bacteriostatic water should be stored refrigerated (2–8°C) and used within 28 days, preferably within 14–21 days for best potency. Do not freeze the reconstituted solution — freeze-thaw cycles denature the peptide and can fragment the DAC linker. Protect from light; amber vials are preferred by compounding pharmacies.
Vial Size
Diluent Added
Concentration
Volume per 1 mg Dose
Volume per 2 mg Dose
2 mg vial
2 mL bacteriostatic water
1,000 mcg / mL
1.00 mL
Full vial
2 mg vial
1 mL bacteriostatic water
2,000 mcg / mL
0.50 mL
1.00 mL
5 mg vial
2.5 mL bacteriostatic water
2,000 mcg / mL
0.50 mL
1.00 mL
5 mg vial
5 mL bacteriostatic water
1,000 mcg / mL
1.00 mL
Full vial
10 mg vial
5 mL bacteriostatic water
2,000 mcg / mL
0.50 mL
1.00 mL
Reconstitution Technique — Protecting the DAC Maleimide: Unlike some peptides that tolerate vigorous mixing, CJC-1295 DAC should be reconstituted gently. Inject bacteriostatic water down the side of the vial wall — not directly onto the lyophilized cake — and swirl gently. Do not vortex or shake the vial. The maleimide group in the DAC linker is susceptible to hydrolysis under agitation and at pH extremes. Vigorous mixing of the reconstituted solution risks maleimide ring-opening before the peptide is administered, which converts CJC-1295 DAC into a non-albumin-binding fragment with dramatically shortened half-life. Gentle inversion 5–10 times until fully dissolved is sufficient and sufficient to preserve linker integrity.
Compounding Source Quality and DAC Linker Verification: An intact, reactive maleimide group cannot be verified by the end user. A compound supplied with a hydrolyzed maleimide will appear identical (clear solution after reconstitution) but will not bind albumin after injection — it behaves pharmacokinetically like Mod-GRF with a ~30-minute half-life rather than 6–8 days. High-performance liquid chromatography (HPLC) purity and mass spectrometry (for correct MW and intact maleimide) are the only methods to verify DAC linker integrity. Request a Certificate of Analysis from the compounding pharmacy that includes: (1) HPLC purity percentage, (2) mass spec confirmation of molecular weight consistent with intact DAC conjugate (~3,636 Da), and (3) lot number traceable to these analyses.
Investigational Dosing Reference
Trial Doses vs. Clinician-Reported Ranges · Two Protocols · No FDA-Approved Protocol
Dosing Framework: The Teichman 2006 trial used 30–120 mcg/kg as single doses — far above the weekly doses used in clinical compounding practice. No dose-ranging human study has been conducted in the clinician-reported weekly-dosing context. The protocols below represent clinician-reported practice, which differs substantially from the published pharmacological data. There is no FDA-approved dosing protocol for CJC-1295.
Protocol A
CJC-1295 with DAC
DoseSet and individualized by the prescribing physician based on baseline IGF-1, body weight, and treatment goals — there is no reader-facing dose for self-administration
FrequencyPhysician-directed; the DAC depot effect supports a less frequent injection interval than Mod-GRF, with the specific schedule determined and adjusted by the treating clinician
TimingNot critical — DAC depot effect makes timing less important than Mod-GRF
With GHRP?Some physician-directed protocols pair CJC-1295 with Ipamorelin for additional pulse amplitude; if used, the dose and timing are determined by the prescribing physician
Cycle lengthDetermined by the prescribing physician and adjusted to monitoring results
MonitoringIGF-1 at baseline and 4–6 weeks; fasting glucose; HbA1c if diabetic risk
Protocol B
Mod-GRF (1-29) + Ipamorelin
Mod-GRF doseSet and individualized by the prescribing physician — there is no reader-facing dose for self-administration
Ipamorelin doseSet and individualized by the prescribing physician, co-administered per the physician's protocol
FrequencyPhysician-directed; this combination is typically administered more frequently than DAC-linked CJC-1295 given its short half-life, with the exact schedule set by the treating clinician
TimingCritical — on empty stomach, per the treating physician's instructions; food (especially carbohydrates) blunts GH release via insulin-mediated somatostatin increase
Cycle lengthDetermined by the prescribing physician and adjusted to monitoring results
MonitoringIGF-1 at 4–6 weeks; target upper-normal range for age (not supranormal); fasting glucose
IGF-1 Monitoring — Upper Limit Target: The goal of GH secretagogue therapy in anti-aging or body composition contexts is to raise IGF-1 into the upper-normal range for age — typically the 75th–90th percentile for the patient's age/sex. Targeting above the age-adjusted upper limit of normal runs the theoretical risk of promoting IGF-1-sensitive tissue growth, including dysplastic or neoplastic tissue. Clinical convention is to check IGF-1 at baseline, 4–6 weeks, and dose-adjust to maintain the target range. Both IGF-1 and IGFBP-3 levels provide a more complete picture of IGF-1 bioavailability than total IGF-1 alone.
GH secretagogue therapy requires active IGF-1 monitoring — not as a formality but as the primary mechanism of dose titration and safety surveillance. CJC-1295 response is highly individual due to variation in baseline pituitary sensitivity, somatostatin tone, body composition, and endogenous GH axis function. IGF-1 measurement at structured intervals is how clinical efficacy and safety are operationally tracked; without it, dose selection is uncalibrated.
①Baseline — Pre-Start
Fasting morning IGF-1 and IGFBP-3. Fasting glucose and HbA1c. Lipid panel. Clinical exam for contraindications. Document the age/sex-adjusted IGF-1 percentile — this is the titration anchor. Patients whose baseline IGF-1 already exceeds the 85th percentile for age are poor candidates.
②4–6 Weeks
Repeat fasting morning IGF-1. For CJC-1295 DAC: sample 4–5 days after the last injection (trough, not immediately post-injection) to capture the sustained elevation, not an acute spike. Fasting glucose. Compare to baseline percentile; adjust dose based on target range.
③12 Weeks
Full panel: IGF-1, IGFBP-3, fasting glucose, HbA1c. Clinical assessment for GH class effects (peripheral edema, joint stiffness, carpal tunnel symptoms, facial fullness). If IGF-1 exceeds upper limit of normal for age, reduce dose or extend injection interval before continuing.
④Cycle End / Washout
Recheck IGF-1 and fasting glucose 4–6 weeks after last dose (washout). Confirms the GH axis has reset; documents the patient's natural post-cycle baseline before any subsequent cycle. Optional: anti-CJC-1295 antibody screening for patients planning repeated long cycles.
IGF-1 Target Range — Research Protocol Context
Sub-OptimalBelow 50th percentile for age/sexConsider dose increase. First verify injection technique, reconstitution quality, DAC maleimide integrity, and cold chain compliance — sub-optimal response may reflect formulation issues rather than pharmacological non-response.
Target Zone75th–90th percentile for age/sexUpper-normal range. Clinical convention for GH secretagogue research protocols: associated with anabolic effects (lean mass, fat reduction, connective tissue) without supraphysiological IGF-1 exposure or its associated risks.
Above TargetAbove age/sex upper limit of normalDose-reduce or extend injection interval immediately. Assess clinically for GH class effects. Avoid sustained supranormal IGF-1 given theoretical neoplasia association in epidemiological cohort literature. Do not continue at current dose.
IGFBP-3 — A More Complete IGF-1 Bioavailability Picture: Insulin-like growth factor binding protein 3 (IGFBP-3) is the primary carrier protein for circulating IGF-1 — approximately 75–90% of IGF-1 in plasma is bound to IGFBP-3 in a ternary complex with ALS (acid-labile subunit). Only free (unbound) IGF-1 is pharmacologically active at the receptor level. Measuring both IGF-1 and IGFBP-3 allows estimation of the free IGF-1 fraction: a patient with normal total IGF-1 but markedly low IGFBP-3 may have disproportionately elevated free IGF-1 bioavailability. Both analytes have well-established age/sex-adjusted reference ranges at most clinical laboratories. Order both at baseline and at the 12-week assessment minimum for a complete GH axis response profile.
Safety Profile
Phase I/II Human Data Available · Surrogate Endpoint Trial · No Long-Term Human Safety Data
📊
Phase I/II Trial Safety
No Serious AEs in Published Trial
Teichman 2006 reported no serious adverse events in n=65 subjects across dose cohorts. Most common: injection site reactions (mild-to-moderate redness, swelling), transient facial flushing post-injection (minutes), occasional headache. No cardiovascular events, no liver enzyme elevations, no pituitary structural changes documented.
📈
IGF-1 Elevation / Neoplasia Risk
Theoretical Concern — No Human Long-Term Data
Chronically elevated IGF-1 is associated with increased risk of colorectal, breast, and prostate cancer in epidemiological cohort studies (not proven causal). Whether the modest IGF-1 elevation produced by research doses of CJC-1295 over months-to-years increases neoplastic risk is unknown — no long-term safety trial has been conducted. Active or recent malignancy is a contraindication.
🩸
Glucose / Insulin Resistance
GH Counter-Regulatory Effect
GH is counter-regulatory to insulin: elevated GH increases hepatic glucose output and reduces peripheral insulin sensitivity. In the Teichman trial, a modest transient increase in fasting glucose was noted. Patients with type 2 diabetes, impaired fasting glucose, or metabolic syndrome should have fasting glucose and HbA1c monitored. CJC-1295 is relatively contraindicated in poorly controlled T2DM.
🦠
Antibody Formation
Low-Titer — Significance Unclear
Low-titer anti-CJC-1295 antibodies were detected in a subset of trial subjects. Whether these antibodies neutralize peptide activity or cause immunological harm with repeated dosing over months is not documented. Peptide immunogenicity is generally low for short sequences but cannot be excluded for long-term multi-dose regimens.
💦
Fluid Retention / Edema
GH Class Effect
GH promotes sodium and water retention via renal mineralocorticoid-like effects. Peripheral edema, joint stiffness, and carpal tunnel syndrome are well-documented GH class effects at higher doses (seen with exogenous hGH). These effects are dose-dependent and generally reversible on discontinuation. Risk is lower with CJC-1295 vs. direct hGH due to the axis-mediated (regulated) GH increase.
🏋️
Acromegalic Features
Not Expected at Research Doses
Acromegaly requires sustained supraphysiological GH elevation over years. Research doses of CJC-1295 are expected to produce IGF-1 in the upper-normal to mildly elevated range, not the 3–5× elevations seen in acromegaly. Periodic IGF-1 monitoring and clinical examination for subtle features (jaw changes, hand/foot growth) are reasonable precautions for multi-year use.
Research Candidate Framework
Surrogate Human Data Available · IGF-1 Monitoring Required · GH Axis Assessment First
Baseline Assessment Requirement: Before initiating any GH secretagogue research protocol, baseline assessment should include: IGF-1 level (age/sex-adjusted), fasting glucose and HbA1c, lipid panel, and a clinical screen for conditions where GH-axis stimulation is contraindicated (active malignancy, diabetic retinopathy, untreated acromegaly, intracranial hypertension). A patient whose baseline IGF-1 is already at the 90th+ percentile for their age is not a strong candidate for additional GH axis stimulation.
✓Stronger Research Candidate Profile
Age-related GH decline (physiological decline begins age 30–35, accelerates after 50): patients with low-normal IGF-1 for age represent the mechanistically strongest candidate profile for GHRH analog use
Body composition goals (increased lean mass, reduced fat mass) in combination with resistance training: GH/IGF-1 axis supports protein synthesis and lipolysis — the evidence base for IGF-1-mediated body composition effects is mechanistically strong even without functional CJC-1295-specific RCT data
Recovery from musculoskeletal injury or surgery: IGF-1 promotes fibroblast proliferation and collagen synthesis; mechanistic rationale for connective tissue and bone healing is supported by IGF-1 biology
Sleep quality optimization goals: GH is the major sleep-architecture-dependent hormone; patients with poor slow-wave sleep may have blunted nocturnal GH pulses; pre-sleep GHRH agonism has theoretical benefit
Normal baseline glucose tolerance and normal-to-low IGF-1 for age: minimizes the glucose counter-regulatory risk and maximizes the likelihood that additional IGF-1 elevation reaches an optimal (not supranormal) range
✗Relative Contraindications / Poor Candidates
Active or recent malignancy: IGF-1 is a known tumor growth promoter; VEGF is also upregulated downstream of IGF-1; this is a hard contraindication — not a relative one
Poorly controlled type 2 diabetes (HbA1c >7.5%): GH counter-regulation will worsen glycemic control; CJC-1295 is not appropriate until diabetes is well-managed
Baseline IGF-1 already in the upper quartile for age: additional stimulation risks driving IGF-1 above physiological range; no benefit if the axis is not limited by GHRH signaling
Active intracranial pathology or elevated intracranial pressure: GH/IGF-1 can worsen intracranial hypertension; contraindicated in patients with benign intracranial hypertension (pseudotumor cerebri) or active CNS lesions
Patients seeking validated clinical outcome data: the strongest evidence is a surrogate endpoint PK/PD trial, n=65. Patients who require Level I evidence for their care decisions should be counseled accordingly — GH secretagogues of any kind lack Phase III functional outcome RCTs.
Comparator Landscape
GH Secretagogues · By Evidence Level, Mechanism, and Regulatory Status
Compound
Evidence
Mechanism
t½
Key Distinction vs. CJC-1295 DAC
CJC-1295 with DAC
Level IIb
GHRHR agonist + DAC albumin depot
6–8 days
This compound. Once-weekly dosing; sustained IGF-1 elevation for 9–11 days per injection; human Phase I/II data available.
Mod-GRF (1-29) / CJC-1295 without DAC
Level V
GHRHR agonist — no albumin binding
~20–30 min
Same receptor, no DAC linker. Level V only — no human clinical trial. Requires pulsatile daily dosing. Almost always combined with Ipamorelin. Lower per-injection cost.
Ipamorelin
Level IIb
GHS-R1a / ghrelin receptor agonist
~2 hrs
Different receptor — complements CJC-1295 rather than replacing it. Human Phase I PK/PD data (Raun 1998). Highly GH-selective; minimal cortisol/prolactin. Typically combined with Mod-GRF rather than used with CJC-1295 DAC.
Sermorelin
Level IIb
GHRHR agonist — GHRH(1-29) without stability modifications
~10–20 min
FDA-approved as diagnostic (withdrawn from market 2008); prior compounding use as anti-aging peptide. Shorter t½ than Mod-GRF; less degradation-resistant than CJC-1295; some human safety data from diagnostic era. Less potent per injection than Mod-GRF due to DPP-IV susceptibility at Ala².
Tesamorelin
Level I
GHRH analog — trans-3-hexenoic acid N-terminal modification
~26 min
FDA-approved for HIV-associated lipodystrophy (Egrifta). The only GHRH analog with Level I evidence and FDA approval. Daily SC injection; approved indication is visceral fat reduction in HIV/ART patients specifically. Level I evidence does NOT extend to other body composition indications in non-HIV populations.
Exogenous hGH (Somatropin)
Level I
Direct GH replacement — GH receptor agonist
~3.8 hrs
FDA-approved for GH deficiency, pediatric short stature, HIV wasting. Bypasses the pituitary; suppresses endogenous axis; flat-line IGF-1 vs. pulsatile CJC-1295 profile. Daily injection. Level I evidence for approved indications only. Unapproved use is a federal violation (Schedule II); significantly higher regulatory and safety profile risk at higher doses.
Tesamorelin — The Evidence Standard for GHRH Analogs: Tesamorelin (Egrifta) underwent the full drug development pathway and achieved Level I evidence and FDA approval for HIV-associated lipodystrophy. Its mechanism is essentially identical to CJC-1295 (GHRH receptor agonist, similar N-terminal modifications for stability). Tesamorelin's success in achieving Level I evidence for a specific indication establishes that GHRH analogs can clear the clinical trial bar — but only for the exact indication studied (HIV lipodystrophy). Extrapolating Tesamorelin's Level I evidence to general body composition, anti-aging, or musculoskeletal indications for CJC-1295 is not scientifically defensible. The two molecules and the two evidence bases are distinct.
A side-by-side comparison of three GH secretagogues — receptor mechanisms, half-lives, evidence levels, and how they differ in clinical research contexts.
Path to Level I Evidence — Why the Ceiling Is Level IIb
ConjuChem Development History · Phase III Requirements · Research Gap Analysis
CJC-1295 occupies a structurally unusual position in the peptide evidence landscape: it has human pharmacodynamic proof-of-concept data that most compounding-market research peptides entirely lack, but it remains well short of the Level I evidence and functional efficacy demonstration required for FDA approval. Understanding why this ceiling exists — and what it would take to raise it — matters for how clinicians and patients interpret the compound's status and its relationship to Tesamorelin, which crossed the same bar that CJC-1295 has not.
IIb
Achieved — Current Level
Phase I/II Human Pharmacodynamic Data
Teichman et al. 2006 (JCEM, PMID 16352683, n=65) established human PK/PD proof of concept: CJC-1295 DAC raises IGF-1 1.5–3× above baseline, maintains pulsatile GH secretion over 6–8 days after a single injection, and was well-tolerated across dose cohorts. This is the current Level IIb achievement — the highest evidence level in the Metabolic Hub outside Tesamorelin. The ceiling: all endpoints are surrogate pharmacodynamic markers (IGF-1, GH-AUC), not functional clinical outcomes (body composition, strength, bone density, quality of life). ConjuChem did not advance beyond Phase II before restructuring.
IIa
Missing — Critical Gap
Controlled Functional Outcome Pilot RCT
A pilot RCT (n=80–120) comparing CJC-1295 DAC vs. placebo with functional endpoints over 6 months in a clinically defined population (e.g., adults 50–70 with low-normal IGF-1 and documented lean mass reduction). Primary endpoint: DXA-measured change in appendicular lean mass. Secondary endpoints: grip strength, 6-minute walk test, fat mass, and IGF-1. This is the critical missing step: it would determine whether CJC-1295-induced IGF-1 elevation translates into measurable functional benefit in humans, and at what dose — neither of which the Teichman trial addressed.
Ib
Aspirational
Phase III Randomized Controlled Trial — Specific Functional Indication
A powered Phase III trial with a functional primary endpoint (DXA lean body mass, VO2max, or another validated clinical measure) over 12+ months in a narrowly defined patient population would establish Level Ib evidence if positive. The Tesamorelin precedent demonstrates the achievability of this pathway for GHRH analogs — the Egrifta Phase III program used DXA-measured visceral fat in HIV/ART patients with lipodystrophy. A narrow, imageable, measurable indication cleared the FDA bar; the same strategic logic would apply to a CJC-1295 Phase III program if a sponsor emerged.
I
Aspirational
FDA Approval / Systematic Review of Multiple RCTs
Level I designation requires either a systematic review of multiple Phase III RCTs or regulatory drug approval. For CJC-1295 specifically, this pathway is effectively closed without a pharmaceutical sponsor who holds IP rights and can fund a full Phase III program. The compounding market provides no regulatory pathway to FDA approval; compounding pharmacies operate under 503A/503B exemptions, not as drug developers. Unless a sponsor acquires and develops CJC-1295 through FDA, Level I evidence for this specific compound will not exist.
Hypothetical Phase IIa Functional Efficacy Trial — What It Would Take
IndicationAge-related sarcopenic GH axis decline in adults 50–70 with baseline IGF-1 ≤50th percentile for age/sex and DXA-confirmed low appendicular lean mass index (ALMI)
DesignRandomized, double-blind, placebo-controlled, 3-arm parallel: CJC-1295 DAC 1 mg/week SC vs. 2 mg/week SC vs. placebo; 24 weeks duration plus 8-week follow-up
Primary EndpointChange in DXA-measured appendicular lean mass (ALM) from baseline to week 24; meaningful threshold: ≥0.5 kg difference vs. placebo (established sarcopenia threshold)
Safety EndpointsHbA1c and fasting glucose monthly; IGF-1 and IGFBP-3 monthly; anti-CJC-1295 antibody titers at baseline, week 12, week 24; OGTT at week 24; clinical AE monitoring; DXA bone density secondary
Sample Sizen=90–120 (30–40/arm); 80% power to detect 0.5 kg ALM difference vs. placebo; allowing 20% dropout rate
Estimated Budget$3–7M for Phase IIa scale. NIH NIA (National Institute on Aging) has historically funded GH secretagogue research — a plausible academic grant pathway; no active pharmaceutical sponsor has announced intent as of the last public records
No Active Development Sponsor
ConjuChem Technologies, the original developer, discontinued CJC-1295 development after Phase II. No pharmaceutical company has publicly announced plans to advance CJC-1295 DAC through Phase III as of current records. Without a sponsor holding IP rights and funding, the compound stays at Level IIb regardless of pharmacological merit.
Regulatory Indication Challenge
FDA approval requires a specific, diagnosable indication with a clinically meaningful, measurable primary endpoint. "Anti-aging," "body composition optimization," and "GH axis decline" are not valid regulatory indications. Sponsors must choose a narrow population with an objective, validated endpoint — exactly what Tesamorelin did with HIV lipodystrophy and DXA-measured visceral fat. The right indication exists; what's missing is sponsor commitment.
Compounding Market Economic Mismatch
A synthetic peptide available through compounding pharmacies cannot be patent-protected in a way that makes a Phase III investment commercially attractive. A sponsor who funds $50–200M in Phase III trials for CJC-1295 would be competing against compounding pharmacies selling the same peptide for a fraction of an approved product's price. The compounding exemption that makes CJC-1295 accessible is the same structure that makes clinical development economically irrational.
Competitive Therapeutic Landscape
GLP-1 receptor agonists (semaglutide, tirzepatide) have dramatically shifted commercial and regulatory attention in metabolic medicine. In a landscape where GLP-1 agents produce 15–22% body weight reduction with Level I evidence, a GH secretagogue targeting lean mass — a narrower and harder endpoint — competes for development resources and clinical attention at a significant disadvantage. This is a market timing problem, not a pharmacological one.
Editorial Position — PeptideReport.ai: CJC-1295 with DAC has more human evidence than the vast majority of compounding-market research peptides. Level IIb is an honest designation that acknowledges both its published human data and the functional efficacy gap. Tesamorelin's regulatory success demonstrates that GHRH receptor agonists can achieve Level I evidence for a well-defined indication — the mechanism is not the barrier. The gap between CJC-1295's current Level IIb status and Level I is commercially and structurally explained, not scientifically unbridgeable. A compound without a sponsor is not the same as a compound without pharmacological promise. But it is definitionally not a compound with clinical trial-grade efficacy evidence — and that distinction must be stated explicitly in evidence-graded clinical practice.
Frequently Asked Questions
CJC-1295 Research Profile — Common Questions
Is CJC-1295 FDA-approved?
No. CJC-1295 with DAC is not FDA-approved for any indication. ConjuChem Technologies completed Phase I/II human trials (Teichman et al. 2006, JCEM) but discontinued development before Phase III, leaving the compound at Level IIb evidence — human pharmacodynamic data without FDA review. It remains accessible only through compounding pharmacies operating under 503A/503B exemptions, not as an approved drug.
What is the difference between CJC-1295 with DAC and CJC-1295 without DAC (Mod-GRF 1-29)?
CJC-1295 with DAC uses a Drug Affinity Complex linker that binds serum albumin, extending its half-life to roughly 6–8 days and supporting once- or twice-weekly dosing. CJC-1295 without DAC is more accurately called Modified GRF (1-29) or Mod-GRF — it lacks the albumin-binding linker, has a half-life of only about 20–30 minutes, and requires more frequent, timing-sensitive dosing. Only CJC-1295 with DAC has the published human trial data (Teichman 2006); Mod-GRF's evidence is Level V, preclinical only.
What does research show about CJC-1295's effect on GH and IGF-1 levels?
The Teichman 2006 Phase I/II trial (n=65 healthy adults) found that CJC-1295 with DAC raised IGF-1 levels 1.5–3× above baseline for 9–11 days after a single injection, and increased GH area-under-curve 2–10× in a dose-dependent manner while preserving the body's natural pulsatile GH secretion pattern. These are pharmacodynamic (surrogate) markers, not clinical outcomes — no published trial has shown that this IGF-1 elevation translates into measurable improvements in muscle mass, fat loss, or other functional endpoints.
Why is CJC-1295 often paired with Ipamorelin?
CJC-1295 (typically the Mod-GRF form in this pairing) and Ipamorelin act on two different receptors — GHRHR and GHS-R1a — on the same pituitary somatotroph cells, triggering separate signaling pathways that converge on GH release. Ipamorelin also suppresses somatostatin tone, which amplifies the GH response to GHRH stimulation. This receptor-level mechanistic rationale is well-supported, but the combination itself has not been evaluated in a published human randomized controlled trial.
What are the main safety and regulatory concerns with CJC-1295?
In the Teichman 2006 trial, reported adverse effects were mild — injection site reactions, transient facial flushing, occasional headache — with no serious adverse events in n=65 subjects. Longer-term concerns include GH's counter-regulatory effect on insulin sensitivity, low-titer antibody formation of unclear significance, and the theoretical association between chronically elevated IGF-1 and neoplastic risk seen in epidemiological cohorts. Because CJC-1295 is compounded rather than FDA-regulated, any use should be supervised by a physician who can order baseline and follow-up IGF-1 and metabolic labs.
Is CJC-1295 the same as human growth hormone (HGH)?
No. CJC-1295 does not supply growth hormone directly — it stimulates the pituitary gland's own GHRH receptor to release GH in the body's natural pulsatile pattern, while exogenous HGH (somatropin) bypasses the pituitary entirely and produces a flat-line, non-pulsatile elevation. Because CJC-1295 works through the intact feedback axis, published data suggest it does not suppress endogenous GH secretion the way direct HGH administration can. Somatropin is FDA-approved for specific indications; CJC-1295 is not.
SD
Dr. Scott DelBoccio, DMD
Founder, PeptideReport.ai · Physician-Authored Research Platform
Dr. Scott DelBoccio, DMD is a retired dentist with thirty years of clinical practice — including a hormone-therapy and regenerative wellness practice built around individual bloodwork, national lecturing on advanced dental and surgical techniques, mentoring new dentists on practice management, and innovating dental and laser procedures now used throughout North America — who is now heavily involved in peptide research and development, building beginner-to-advanced optimization frameworks calibrated to the individual, and holds workshops and lectures on peptide therapeutics for other clinicians and researchers. CJC-1295 occupies a unique position in the Metabolic Hub — it has published human pharmacodynamic data (Level IIb), which distinguishes it from Level V compounds like BPC-157, while remaining far from the Level I evidence and FDA approval achieved by Tesamorelin. The profile covers: critical disambiguation of CJC-1295 with DAC vs. Mod-GRF 1-29; molecular architecture and DAC maleimide chemistry; the Teichman 2006 Phase I/II trial with honest limitations analysis; GH pulsatility and the CJC-1295 + Ipamorelin dual-axis stack; reconstitution and storage protocols specific to the DAC linker; a structured IGF-1 lab monitoring framework; and a research gap analysis examining why the Level IIb ceiling exists and what a path to Level I would require. PeptideReport.ai is committed to honest, evidence-graded content. Nothing on this page constitutes prescribing guidance, clinical recommendation, or a patient-provider relationship.