CJC-1295: The Complete Growth Hormone Secretagogue Guide
Last updated: April 14, 2026 · 16 min read · Reviewed by Grey Peptides Editorial Board
TL;DR
CJC-1295 is a synthetic analog of growth hormone releasing hormone (GHRH) that stimulates the pituitary gland to produce and release more growth hormone. It exists in two forms: CJC-1295 with DAC (Drug Affinity Complex), which has a ~6–8 day half-life and allows weekly dosing, and CJC-1295 without DAC (also called Modified GRF 1–29 or Mod GRF), which has a ~30-minute half-life and requires daily dosing but preserves natural pulsatile GH release. The no-DAC version is preferred for most use cases, particularly when stacked with Ipamorelin. Published human data demonstrates that CJC-1295 produces sustained, dose-dependent increases in GH and IGF-1 levels, with IGF-1 elevations of 1.5–3x baseline lasting up to 14 days after a single injection (DAC version).
→ Explore CJC-1295 in the Peptide Encyclopedia.
→ Calculate your dosing with the Reconstitution Calculator.
Table of Contents
- What Is CJC-1295?
- Origin & Development
- Molecular Profile
- Mechanism of Action
- DAC vs No DAC: The Critical Distinction
- Human Clinical Data
- Dosing Protocols
- Reconstitution & Administration
- Side Effects & Safety
- Legal & Regulatory Status
- Stacking CJC-1295
- CJC-1295 vs Other GH Peptides
- Frequently Asked Questions
- Sources
What Is CJC-1295?
CJC-1295 is a synthetic peptide consisting of 29 amino acids that mimics the action of growth hormone releasing hormone (GHRH) — the hypothalamic hormone responsible for signaling the anterior pituitary to synthesize and secrete growth hormone. By activating the GHRH receptor on pituitary somatotroph cells, CJC-1295 amplifies the body's natural GH production without bypassing the regulatory feedback mechanisms that govern hormone release.
This makes CJC-1295 fundamentally different from exogenous growth hormone (HGH) injections. HGH introduces external growth hormone directly, overriding the pituitary's role entirely. CJC-1295 instead tells the pituitary to produce more of its own GH, maintaining the body's natural pulsatile release pattern and feedback regulation.
The peptide was originally developed by ConjuChem Biotechnologies (now ConjuChem LLC) as a potential therapeutic for growth hormone deficiency and age-related GH decline. It advanced through Phase 1 and 2 clinical trials before development was paused due to a serious adverse event during testing.
Origin & Development
CJC-1295 was designed by modifying the first 29 amino acids of GHRH (the biologically active portion) to create a peptide with dramatically improved stability and half-life. Natural GHRH (also called GRF 1–44 or sermorelin for the first 29 amino acids) is rapidly degraded by the enzyme dipeptidyl peptidase IV (DPP-IV) after injection, giving it a half-life of only ~7 minutes — far too short for practical therapeutic use.
ConjuChem's modification involved four amino acid substitutions at positions 2, 8, 15, and 27 that confer resistance to DPP-IV degradation while preserving full biological activity at the GHRH receptor. This modified peptide — sometimes called tetrasubstituted GRF 1–29 or Modified GRF 1–29 — has a half-life of approximately 30 minutes.
To extend the half-life further, ConjuChem conjugated this modified peptide to a Drug Affinity Complex (DAC) — a maleimidopropionic acid linker that covalently bonds to albumin in the bloodstream after injection. This albumin-bound form circulates for days rather than minutes, resulting in a half-life of approximately 6–8 days.
Both forms — with and without DAC — are commonly referred to as "CJC-1295," which causes significant confusion in the peptide community. Understanding the distinction is critical for proper use.
Molecular Profile
| Property | CJC-1295 (no DAC / Mod GRF 1–29) | CJC-1295 with DAC |
|---|---|---|
| Amino acids | 29 | 29 + DAC conjugate |
| Molecular weight | ~3,367 Da | ~3,647 Da (with linker) |
| 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-NH₂ | Same peptide + MPA-DAC |
| Half-life | ~30 minutes | ~6–8 days |
| Bioavailability | SubQ injection | SubQ injection |
| Target receptor | GHRH-R (pituitary) | GHRH-R (pituitary) |
| DPP-IV resistant | Yes (4 substitutions) | Yes (4 substitutions + albumin binding) |
| GH release pattern | Pulsatile (acute spike, returns to baseline in hours) | Sustained (elevated baseline for days) |
| Storage | Lyophilized: room temp stable. Reconstituted: refrigerate, use within 28 days. | Same |
Mechanism of Action
CJC-1295's mechanism is straightforward: it binds to the GHRH receptor on pituitary somatotroph cells and initiates the same intracellular signaling cascade as natural GHRH.
The GHRH receptor signaling pathway:
- CJC-1295 binds to the GHRH receptor (a G protein-coupled receptor) on the surface of pituitary somatotroph cells
- This activates adenylyl cyclase via the Gs alpha subunit
- Intracellular cAMP levels rise
- cAMP activates protein kinase A (PKA)
- PKA phosphorylates transcription factors that drive GH gene expression and triggers calcium influx that triggers vesicle release
- Stored GH is released from secretory granules into the bloodstream, and new GH synthesis is upregulated
The key pharmacological advantage: The four amino acid substitutions make CJC-1295 resistant to DPP-IV — the enzyme that normally breaks down GHRH within minutes. This means CJC-1295 continues activating the GHRH receptor long after natural GHRH would have been cleared, producing a larger and more sustained GH pulse.
Pulsatile vs sustained GH release: This is where the DAC vs no-DAC distinction becomes mechanistically important. Without DAC, CJC-1295 creates a large pulse that resolves within 2–3 hours — closely mimicking a natural GHRH pulse but bigger. With DAC, the albumin-bound peptide creates a sustained GHRH signal lasting days, producing a chronically elevated GH baseline rather than discrete pulses.
The distinction matters because pulsatile GH release (the no-DAC pattern) is more effective for lipolysis and IGF-1 signaling than continuous GH elevation. The body responds to GH pulses differently than to sustained GH levels — this is why endogenous GH is released in bursts rather than continuously.
DAC vs No DAC: The Critical Distinction
This section expands on the most important practical decision anyone using CJC-1295 faces.
CJC-1295 Without DAC (Modified GRF 1–29)
Half-life: ~30 minutes GH release pattern: Sharp pulse, peaks within 15–30 minutes, returns near baseline within 2–3 hours Dosing frequency: Daily (typically at bedtime) Advantages:
- Preserves natural pulsatile GH dynamics
- Lower risk of insulin resistance and side effects associated with sustained GH elevation
- Can be precisely timed to amplify the natural sleep-associated GH pulse
- Synergizes optimally with Ipamorelin (both create simultaneous pulses)
- Allows full pituitary recovery between doses
Disadvantages:
- Requires daily injection
- Each dose creates a relatively short-lived effect
CJC-1295 With DAC
Half-life: ~6–8 days GH release pattern: Sustained elevation above baseline for 5–7 days after injection Dosing frequency: 1–2x per week Advantages:
- Fewer injections (1–2x/week vs daily)
- Convenient for people who find daily injection burdensome
- Produces stronger sustained IGF-1 elevation
Disadvantages:
- Non-pulsatile GH elevation (less physiological)
- Higher risk of dose-dependent side effects (water retention, insulin resistance)
- Suboptimal synergy with Ipamorelin (mismatched temporal profiles)
- Pituitary cannot fully "rest" between doses — potential for desensitization with prolonged use
The Recommendation
For most users, the no-DAC version is preferred. The pulsatile GH release pattern is more physiological, produces fewer side effects, and synergizes properly with Ipamorelin in the gold standard GH stack. The daily injection requirement is a minor inconvenience for a significantly better pharmacological profile.
The DAC version makes sense only when injection frequency is a major barrier and you're using CJC-1295 as a standalone (not stacked with a ghrelin mimetic).
→ Detailed analysis: CJC-1295 DAC vs No DAC.
Human Clinical Data
Teichman et al. (2006) — The Key Study
The most frequently cited human study of CJC-1295 was published by Teichman et al. in the Journal of Clinical Endocrinology & Metabolism. This was a single-blind, placebo-controlled, dose-escalation study of CJC-1295 with DAC in healthy subjects aged 21–61.
Key findings:
- Single subcutaneous doses (30–300 μg/kg) produced dose-dependent increases in mean GH levels of 2–10x above baseline
- IGF-1 levels increased 1.5–3x above baseline and remained elevated for 6–14 days after a single injection
- After multiple weekly doses, IGF-1 elevation was sustained at 1.5–3x baseline for the duration of the dosing period
- GH and IGF-1 responses were consistent across age groups
- The pulsatile pattern of GH release was preserved (important: even the DAC version maintained some pulsatility, just with an elevated baseline)
Safety Signals
Clinical development of CJC-1295 with DAC was halted after a serious adverse event during Phase 2 trials. While the specifics are not fully public, this event has led some researchers and practitioners to prefer the no-DAC version, which has a shorter duration of action and thus a more controllable safety profile.
No serious adverse events have been specifically attributed to Modified GRF 1–29 (no DAC) in published literature, though formal clinical trial data for this version is limited.
Limitations
The published human data has significant limitations: small sample sizes, short durations, and focus on GH/IGF-1 biomarkers rather than clinical outcomes like body composition, muscle mass, or fat loss. Most of the clinical endpoints that users care about (how much fat will I lose, how much muscle will I gain, how will my sleep improve) have not been formally studied in controlled trials.
Dosing Protocols
Standard Protocol (No DAC — Most Common)
| Parameter | Value |
|---|---|
| Dose | 100 mcg per injection |
| Frequency | Once daily |
| Timing | Bedtime, on empty stomach (no food 1.5+ hours prior) |
| Route | Subcutaneous (abdominal preferred) |
| Cycle length | 8–16 weeks |
| Off-cycle | 4–8 weeks |
Stack Protocol (With Ipamorelin — Gold Standard)
| Peptide | Dose | Frequency | Timing |
|---|---|---|---|
| CJC-1295 (no DAC) | 100 mcg | Daily | Bedtime, empty stomach |
| Ipamorelin | 200–300 mcg | Daily | Bedtime, empty stomach (same injection) |
Both peptides are drawn into the same insulin syringe and injected together. The dual GHRH + ghrelin receptor activation produces a synergistic GH pulse.
→ Full stack guide: CJC-1295 + Ipamorelin Stack.
Twice-Daily Protocol (Enhanced)
| Dose | Timing | Condition |
|---|---|---|
| 100 mcg CJC + 200 mcg Ipamorelin | Morning (fasted) | At least 8 hours after last meal |
| 100 mcg CJC + 200 mcg Ipamorelin | Bedtime | 1.5+ hours after last food |
Two GH pulses per day — morning fasted and bedtime. This protocol is used by advanced users seeking maximum GH optimization.
DAC Protocol (For Those Who Choose It)
| Dose | Frequency |
|---|---|
| 2 mg | Once weekly (or 1 mg twice weekly) |
Inject subcutaneously, any time of day. Food timing is less critical with the DAC version because the sustained release makes individual meal timing less impactful on the GH response.
→ Calculate your exact reconstitution volumes and syringe units: Reconstitution Calculator.
Reconstitution & Administration
CJC-1295 arrives as a lyophilized white powder in sealed glass vials, typically in 2 mg or 5 mg sizes.
Standard Reconstitution
- Swab the vial stopper with an alcohol pad
- Draw 2 mL bacteriostatic water into a mixing syringe (21–25g needle)
- Insert needle into the vial and direct water down the inside wall
- Allow water to flow slowly — never spray directly onto powder
- Remove syringe, gently swirl until completely dissolved (do not shake)
- Label with peptide name, concentration, and date
- Refrigerate immediately
Concentration Reference
| Vial Size | BAC Water | Concentration | 100 mcg = |
|---|---|---|---|
| 2 mg | 2 mL | 1 mg/mL | 10 units |
| 5 mg | 2 mL | 2.5 mg/mL | 4 units |
Injection Technique
Use a fresh U-100 insulin syringe (29–31 gauge). Inject subcutaneously into a pinch of abdominal fat. Rotate injection sites to prevent lipodystrophy. Dispose of needles in a sharps container.
→ Step-by-step technique: How to Inject Peptides Subcutaneously.
→ Full reconstitution walkthrough: How to Reconstitute Peptides.
Side Effects & Safety
Common (Mild, Transient)
Facial flushing / head rush (15–20%). Occurs within minutes of injection due to acute GH release. Resolves spontaneously in 5–15 minutes. Generally considered a sign the peptide is active.
Injection site reactions. Mild redness or welting at the injection site. Resolves within an hour. Rotate sites to minimize.
Water retention. Mild fluid retention in the first 1–2 weeks. Usually resolves as the body adjusts. May show as 1–3 lbs on the scale.
Uncommon
Tingling in extremities. Occasional numbness or tingling, usually transient. May indicate fluid retention pressing on peripheral nerves. Reduce dose if persistent.
Increased appetite. Some users report modest hunger increase, though this is more commonly associated with ghrelin mimetics (Ipamorelin, GHRP-6) than with CJC-1295 alone.
Dose-Dependent Concerns
Insulin resistance. Growth hormone has counter-regulatory effects on insulin. Elevated GH can reduce insulin sensitivity, particularly at higher doses or with the DAC version's sustained elevation. Monitor fasting insulin and glucose via bloodwork.
Joint stiffness / carpal tunnel symptoms. Indicators of excessive GH elevation. Reduce dose or extend time between cycles if these appear.
Long-Term Considerations
Long-term safety data for CJC-1295 in humans is limited. Cycling (8–16 weeks on, 4–8 weeks off) is recommended to prevent pituitary desensitization and allow metabolic parameters to normalize. Regular bloodwork (IGF-1, fasting insulin, glucose) is essential for safe use.
Legal & Regulatory Status
CJC-1295 is not FDA-approved for any indication. Its legal status varies by jurisdiction:
- United States: Available as a research chemical. Not approved for human therapeutic use. Some compounding pharmacies produce it under 503A/503B regulations for physician-prescribed use.
- Australia: Schedule 4 (prescription only). Available through anti-aging and TRT clinics.
- United Kingdom: Not licensed. Available through research chemical suppliers.
- Canada: Not approved by Health Canada. Available through research channels.
- WADA: Prohibited at all times (S2: Peptide Hormones, Growth Factors). Not permitted in any tested competitive sport.
→ Full legal breakdown: Are Peptides Legal? 2026 Guide.
Stacking CJC-1295
CJC-1295 (no DAC) is most effective as part of a stack. It provides the GHRH component — the "ignition" for GH release — but benefits significantly from a ghrelin mimetic that provides the "amplification."
Primary Stack: CJC-1295 + Ipamorelin (Gold Standard)
The most widely used and recommended combination. Dual-pathway GH stimulation with Ipamorelin's clean selectivity profile.
→ Full guide: CJC-1295 + Ipamorelin Stack Guide.
Recovery Stack: CJC-1295 + Ipamorelin + BPC-157
Adding BPC-157 introduces localized tissue repair and GH receptor upregulation, potentially amplifying the benefit of elevated GH from the secretagogue stack.
Full Optimization: CJC-1295 + Ipamorelin + BPC-157 + TB-500
Maximum GH optimization with comprehensive repair signaling — both localized (BPC-157) and systemic (TB-500).
→ Verify any combination: Interaction Checker.
→ Build custom protocols: Protocol Builder.
CJC-1295 vs Other GH Peptides
| Peptide | Type | Half-life | GH Pattern | Selectivity | Human Data |
|---|---|---|---|---|---|
| CJC-1295 (no DAC) | GHRH analog | ~30 min | Pulsatile | High | Limited |
| CJC-1295 (DAC) | GHRH analog | ~6–8 days | Sustained | High | Phase 1/2 |
| Sermorelin | GHRH analog | ~7 min | Pulsatile | High | FDA-approved (discontinued) |
| Tesamorelin | GHRH analog | ~26 min | Pulsatile | High | FDA-approved |
| Ipamorelin | Ghrelin mimetic | ~2 hours | Pulsatile | Very high | Phase 2 |
| GHRP-6 | Ghrelin mimetic | ~20 min | Pulsatile | Low (↑cortisol, prolactin) | Limited |
| GHRP-2 | Ghrelin mimetic | ~25 min | Pulsatile | Moderate | Limited |
| MK-677 | Ghrelin mimetic (oral) | ~24 hours | Sustained | Low (↑cortisol, appetite) | Phase 2 |
| HGH | Exogenous GH | ~2–3 hours | Spike | N/A | Extensive |
CJC-1295 vs Sermorelin: Both are GHRH analogs, but CJC-1295 has a ~4x longer half-life due to DPP-IV resistance. Sermorelin requires more frequent dosing and produces a smaller GH pulse per injection. CJC-1295 has largely replaced sermorelin in practice.
CJC-1295 vs Tesamorelin: Tesamorelin has the advantage of FDA approval (for HIV-associated lipodystrophy) and more robust clinical trial data. CJC-1295 is available at lower cost through research channels. Mechanism is similar — both are GHRH analogs with DPP-IV resistance.
→ Run any head-to-head comparison: Comparison Tool.
Frequently Asked Questions
How do I know if CJC-1295 is working? The most reliable indicator is IGF-1 blood levels — test at baseline and again at weeks 4–6. An increase of 25–50%+ above baseline confirms effective GH stimulation. Subjective signs include improved sleep quality (within 1–2 weeks), enhanced recovery, and gradual body composition changes (weeks 6–12).
Can women use CJC-1295? Yes. CJC-1295 does not affect sex hormones (testosterone, estrogen, progesterone). Women can expect the same benefits — improved sleep, body recomposition, recovery, skin quality. Dosing is typically identical to men's protocols.
Does CJC-1295 affect testosterone? No. CJC-1295 acts exclusively on the GHRH receptor to stimulate GH release. It does not interact with gonadotropin pathways (LH, FSH) or androgen receptors. It has no impact on testosterone production.
What happens when I stop taking CJC-1295? GH and IGF-1 levels return to baseline within 1–2 weeks after stopping (no DAC) or 2–4 weeks (DAC). There is no "crash" or withdrawal. No post-cycle therapy is needed. Your pituitary resumes normal function.
Why not just take HGH directly? CJC-1295 maintains natural pulsatile GH release and pituitary function, costs significantly less ($100–200/month vs $500–2,000+/month for HGH), and carries lower risk of the side effects associated with supraphysiological GH levels. HGH provides more precise GH dosing and has extensive clinical data. The choice depends on budget, goals, and access.
Related Tools & Articles
- Reconstitution Calculator — Calculate CJC-1295 dosing
- Protocol Builder — Build a GH optimization protocol
- Interaction Checker — Verify stack safety
- Comparison Tool — Compare CJC-1295 vs alternatives
- CJC-1295 + Ipamorelin Stack Guide
- Best Peptides for Muscle Growth 2026
Sources
- Teichman, S. L. et al. (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. Journal of Clinical Endocrinology & Metabolism, 91(3), 799–805. PMID: 16352683
- Alba, M. et al. (2006). Once-daily administration of CJC-1295, a long-acting growth hormone-releasing hormone (GHRH) analog, normalizes growth in the GHRH knockout mouse. American Journal of Physiology, 291(6), E1290–E1294. PMID: 16822960
- Ionescu, M. & Bhatt, D. L. (2008). Sustained stimulation of growth hormone by CJC-1295, a synthetic GHRH analog. Growth Hormone & IGF Research, 18(Suppl 1), S1–S45.
- Bowers, C. Y. (2012). History to the discovery of ghrelin. Methods in Enzymology, 514, 3–32. PMID: 22975044
- Veldhuis, J. D. et al. (2006). Joint mechanisms of impaired growth-hormone pulse renewal in aging men. Journal of Clinical Endocrinology & Metabolism, 91(12), 4792–4799. PMID: 16984991
- Sigalos, J. T., & Pastuszak, A. W. (2018). The Safety and Efficacy of Growth Hormone Secretagogues. Sexual Medicine Reviews, 6(1), 45–53. PMID: 29174957
- Van Cauter, E., & Plat, L. (1996). Physiology of growth hormone secretion during sleep. Journal of Pediatrics, 128(5), S32–S37. PMID: 8627466
Medical Disclaimer: This article is for educational and informational purposes only. CJC-1295 is not FDA-approved for any indication. Growth hormone optimization should be pursued under the supervision of a licensed healthcare professional with regular bloodwork monitoring. Do not begin any GH-modulating protocol without medical guidance.
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This article is for educational purposes only and does not constitute medical advice. Consult a licensed medical professional before considering any peptide therapy.