CJC-1295 (Mod GRF 1-29)
Growth Hormone / IGF-1 AxisPreclinicalAlso known as: CJC no DAC, CJC-1295 no DAC, Modified GRF 1-29
CJC-1295 without DAC (also called Modified GRF 1-29 or MOD-GRF 1-29) is a 30-amino-acid analog of the first 29 residues of endogenous Growth Hormone Releasing Hormone (GHRH), with four strategic substitutions (D-Ala² for DPP-4 resistance, Gln⁸, Ala¹⁵, Leu²⁷) that extend its plasma half-life from <2 minutes (native GHRH) to ~30 minutes. It was developed by ConjuChem Biotechnologies as the non-albumin-binding companion to CJC-1295 with DAC. This is the physiologic version of CJC-1295.
Reconstitution Calculator for CJC-1295 (Mod GRF 1-29)
Pre-filled · 2mg vial · 100mcg dose
Overview
At A Glance
MOD-GRF 1-29 exerts its effect through a single, well-characterized receptor: the GHRH receptor (GHRHR) on anterior-pituitary somatotroph cells. The signaling cascade is the same as endogenous GHRH; the difference is pharmacokinetics.…
Mechanism of Action
MOD-GRF 1-29 exerts its effect through a single, well-characterized receptor: the GHRH receptor (GHRHR) on anterior-pituitary somatotroph cells. The signaling cascade is the same as endogenous GHRH; the difference is pharmacokinetics.
1. GHRH receptor agonism (Gs/cAMP/PKA pathway)
- GHRHR is a Class B1 G-protein-coupled receptor with high-affinity binding for the N-terminal fragment of GHRH
- Ligand binding activates Gs, elevating intracellular cAMP
- cAMP activates PKA, which phosphorylates CREB
- Phospho-CREB upregulates GH-1 gene transcription and mobilizes preformed GH from secretory granules
- Result: acute GH release within 15-30 minutes of injection
MOD-GRF 1-29 has ~15-fold higher potency at GHRHR than native GHRH due to its DPP-4 resistance and extended circulating half-life (Teichman et al., 2006).
2. Pulsatile GH release (key physiologic advantage)
Because MOD-GRF 1-29 clears from plasma in ~30 min (vs ~8 days for CJC-1295 with DAC), it produces a sharp, transient GH pulse rather than sustained elevation. This preserves:
- Somatotroph sensitivity — continuous GHRH exposure desensitizes pituitary receptors; pulsatile exposure does not
- Negative-feedback regulation — somatostatin (GHIH) can appropriately suppress GH between pulses
- Circadian integration — amplifies rather than replaces the natural nocturnal GH burst
This is the reason most clinicians prefer MOD-GRF 1-29 over the DAC variant for long-term protocols.
3. Synergy with ghrelin-receptor agonists
The combination MOD-GRF 1-29 + ipamorelin (or hexarelin, or MK-677) is the backbone of modern GH secretagogue protocols:
- GHRH pathway: Gs → cAMP → PKA → CREB
- Ghrelin pathway: Gq/11 → PLC → IP₃ → Ca²⁺ mobilization
- Pathways converge on the same somatotroph but through distinct second messengers
- Net GH pulse is 3-5x larger than either drug alone (Bowers et al., 1991; Raun et al., 1998)
This synergy is the primary reason biohackers dose them together; using MOD-GRF 1-29 alone produces a measurable but modest GH rise.
4. Downstream IGF-1 elevation
- Released GH binds hepatic GH receptors (JAK2/STAT5 signaling)
- Induces hepatic IGF-1 mRNA expression
- Plasma IGF-1 rises with a 1-3 day lag after chronic dosing
- Multi-week dosing achieves 1.5-2x baseline IGF-1 (less than CJC-1295 with DAC's 1.5-3x because MOD-GRF 1-29 is pulsatile, not sustained)
5. What MOD-GRF 1-29 does NOT do
- Does not bind ghrelin receptor (GHS-R1a) — this is ipamorelin's role
- Does not stimulate cortisol, prolactin, or ACTH at therapeutic doses (unlike older GHRPs)
- Does not cross blood-brain barrier in appreciable quantities (effects are peripheral)
- Does not bypass endogenous feedback — very high somatostatin tone (e.g., postprandial, hyperglycemia) blunts the GH response
Practical implication: Take MOD-GRF 1-29 in a fasted state or >2 hours post-carbohydrate meal to avoid somatostatin-mediated blunting.
Overview
CJC-1295 without DAC (also called Modified GRF 1-29 or MOD-GRF 1-29) is a 30-amino-acid analog of the first 29 residues of endogenous Growth Hormone Releasing Hormone (GHRH), with four strategic substitutions (D-Ala² for DPP-4 resistance, Gln⁸, Ala¹⁵, Leu²⁷) that extend its plasma half-life from <2 minutes (native GHRH) to ~30 minutes. It was developed by ConjuChem Biotechnologies as the non-albumin-binding companion to CJC-1295 with DAC.
This is the physiologic version of CJC-1295. Because its half-life is short, each subcutaneous injection produces a single sharp GH pulse peaking at 30-60 minutes and returning to baseline within 2-3 hours — a pattern nearly identical to the body's natural nocturnal GH burst. This is in deliberate contrast to CJC-1295 with DAC, which produces continuous, non-pulsatile GH elevation over 1-2 weeks and is considered by many clinicians to be supra-physiologic.
MOD-GRF 1-29 is almost always stacked with a ghrelin receptor agonist (ipamorelin, hexarelin, or MK-677) because the two signaling pathways converge synergistically on pituitary somatotrophs: GHRH activates the Gs/cAMP/PKA pathway while ghrelin-receptor activation triggers phospholipase-C/IP₃/calcium mobilization. Dual activation produces a GH pulse 3-5x greater than either agent alone (Bowers et al., GH synergy).
Typical dosing: 100 mcg SC 1-3x daily (pre-bed is most common; fasted state optimizes GH response), often alongside 100-200 mcg ipamorelin at the same injection.
Key regulatory note: CJC-1295 is not FDA-approved for any indication. Clinical development was halted at Phase 2. It is used extensively in integrative and anti-aging medicine via compounding pharmacy and is widely available as research-use peptide. The related molecule sermorelin (GRF 1-29 without the substitutions) was FDA-approved for pediatric GHD and is available as a compounded prescription in the US (Tesar, 2010).
See our CJC-1295 Dosage Guide and Reconstitution Tool for protocol specifics. The DAC variant is documented separately at /compound/cjc-1295-dac.
Potential Research Fields
Chemical Information
IUPAC Name
Modified GRF(1-29) with 4 amino acid substitutions
CAS Number
863288-34-0
Molecular Formula
C165H271N47O46
Molecular Mass
3367.9 g/mol
Dosing & Protocols
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Interactions
Interaction Matrix
Contraindications
Absolute contraindications
- Active malignancy of any type — GH/IGF-1 axis stimulation is theoretically pro-tumorigenic; substantive epidemiologic signal for prostate, colorectal, and premenopausal breast cancer (Renehan et al., 2004)
- Diabetic retinopathy (active or history) — IGF-1 promotes retinal neovascularization
- Pregnancy and lactation — no safety data, GH axis alterations during pregnancy have unknown consequences
- Children with open growth plates — unintended longitudinal growth
- Critical illness requiring ICU care — exogenous GH increased mortality in critically ill patients (Takala et al., 1999, NEJM)
Relative contraindications (clinician-guided)
- History of cancer within 5 years — individualize risk/benefit with oncology
- Type 2 diabetes with poor control (HbA1c >8) — GH worsens insulin resistance
- Severe hypothyroidism — suboptimal GH response; optimize thyroid first
- Intracranial pathology / elevated ICP — theoretical concern with GH
- Obstructive sleep apnea — GH may exacerbate upper-airway soft tissue
Drug interactions
- Glucocorticoids (prednisone, dexamethasone) — blunt GHRH response; minimize if possible
- Somatostatin analogs (octreotide, lanreotide) — direct GH suppression; incompatible use
- Insulin and insulin secretagogues — GH is counter-regulatory; monitor glucose
- Oral estrogens (high-dose) — blunt hepatic IGF-1 response
- Chemotherapy agents — avoid concurrent use during active chemo
Surgery and procedure considerations
- Hold for 1-2 weeks before elective major surgery (conservative)
- Disclose use to all clinicians, particularly oncology, ophthalmology, endocrinology
- Not a concern for routine procedures (dental, dermatologic)
Disclosure obligations
- All clinicians, especially oncology, ophthalmology, endocrinology
- Insurance and life-insurance applications (material in some jurisdictions)
- Anti-doping: GH-releasing peptides are WADA-prohibited at all times — not appropriate for competitive athletes subject to testing
Research Disclaimer
This interaction data is compiled from published research and community reports. It may not be exhaustive. Always consult a healthcare professional before combining compounds.
$29.00
up to $49.99
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vial, blend
| Vendor | Product | Form | Qty | Price | $/mg | Coupon | |
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CJC-1295/Ipamorelin | blend | 1 vial● In Stock | $49.99BEST | $4.999 | ||
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CJC-1295 (No DAC) 5mg | vial | 1 vial● Out of Stock | $29.00 | $5.800 | — | Sign in for stock alert |
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CJC-1295 (No DAC) 10mg | vial | 1 vial● In Stock | $49.00 | $4.900 | — | |
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CJC/Ipa 5+5mg | blend | 1 vial● In Stock | $46.99 | $4.699 | — | |
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CJC No DAC 2mg | vial | 2mg vial● In Stock | $29.99 | $14.995 | ||
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CJC No DAC 5mg | vial | 5mg vial● In Stock | $39.99 | $7.998 |
Tracking since Apr 6, 2026 · 4 data points
Price History
2 data pointsVendors Selling CJC-1295 (Mod GRF 1-29)
Ion Peptide
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ResearchChemHQ
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Related Compounds
View AllCJC-1295 with DAC
Growth Hormone / IGF-1 AxisPhase 2CJC-1295 with DAC (Drug Affinity Complex) is a modified form of CJC-1295 that incorporates a maleimidopropionic acid (MPA) reactive group at the C-terminus.
GHRP-2
Growth Hormone / IGF-1 AxisPhase 2GHRP-2 (growth hormone-releasing peptide-2), also known as pralmorelin and KP-102, is a synthetic hexapeptide growth hormone secretagogue that was among the first GHRPs developed in the seminal research of Cyril Bowers and colleagues at Tulane University in the late 1980s and early 1990s.
GHRP-6
Growth Hormone / IGF-1 AxisPhase 2GHRP-6 (growth hormone-releasing peptide-6) is a synthetic hexapeptide with the sequence His-D-Trp-Ala-Trp-D-Phe-Lys-NH2 that binds the ghrelin receptor (GHS-R1a) to stimulate endogenous growth hormone release.
Hexarelin
Growth Hormone / IGF-1 AxisPhase 2Hexarelin (also called examorelin) is a potent synthetic hexapeptide growth hormone secretagogue with the sequence His-D-2-methyl-Trp-Ala-Trp-D-Phe-Lys-NH2.
IGF-1 LR3
Growth Hormone / IGF-1 AxisPhase 2IGF-1 LR3 (Long R3 IGF-1) is a synthetic analog of human insulin-like growth factor 1 modified at two positions to dramatically extend its serum half-life and amplify its tissue bioactivity compared to native IGF-1.
Ipamorelin
Growth Hormone / IGF-1 AxisPreclinicalIpamorelin is a selective pentapeptide ghrelin receptor (GHS-R1a) agonist — one of the most studied growth hormone secretagogues (GHS) in the biohacking community and the modern companion to CJC-1295 / MOD-GRF 1-29.
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Protocols, calculator & safety for CJC-1295 (Mod GRF 1-29)
Research Score
29 PubMed studies
Quality Indicators
Data Completeness
100%COA Verification
6
Verified COAs
1
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High verification rate (100%)
Latest test: 12/5/2024
Research Credibility
Quick Facts
Half-Life
~30 minutes (without DAC / MOD-GRF 1-29); 8+ days (with DAC, due to covalent albumin binding)
Molecular Weight
3367.9 g/mol
Administration
Subcutaneous
CAS Number
863288-34-0
Trial Phase
Preclinical
Safety Profile
Common Side Effects
- • Injection site redness, swelling, or itching
- • Flushing and warmth sensation (vasodilation) 15-30 minutes post-injection
- • Water retention and mild edema during initial weeks
- • Transient hunger increase
- • Headache (typically resolves with continued use)
Research Disclaimer
This information is for educational and research purposes only. Not intended as medical advice. Consult a healthcare professional before use.
Frequently Asked Questions
What's the difference between CJC-1295 and CJC-1295 with DAC?
CJC-1295 without DAC (also called MOD-GRF 1-29) has a ~30-minute plasma half-life and produces a sharp, pulsatile GH release similar to natural physiology. CJC-1295 with DAC has a maleimide linker that binds serum albumin, extending the half-life to ~8 days and producing continuous, non-pulsatile GH elevation. Most modern clinicians prefer the non-DAC version because pulsatile release preserves somatotroph sensitivity and endogenous negative feedback. The DAC version is more convenient (once-weekly) but carries higher risk of receptor desensitization and sustained supraphysiologic IGF-1. See the /compound/cjc-1295-dac page for the DAC-specific profile.
Why do I need to stack MOD-GRF 1-29 with ipamorelin?
Used alone, MOD-GRF 1-29 produces a measurable but modest GH pulse (~2-3x baseline). When combined with a ghrelin-receptor agonist like ipamorelin, the two signaling pathways converge synergistically on pituitary somatotrophs — GHRH activates Gs/cAMP/PKA while ghrelin activates Gq/PLC/IP₃/Ca²⁺. The net GH pulse is 3-5x larger than either agent alone. This synergy is well-documented (Bowers 1991) and is the mechanistic rationale for every modern GH secretagogue protocol. Dosing MOD-GRF 1-29 without a ghrelin-axis partner is leaving efficacy on the table.
Will CJC-1295 help me build muscle?
Modestly, and only in combination with resistance training and adequate protein intake. GH and IGF-1 elevation alone produce minimal hypertrophy — the signal supports protein synthesis but does not substitute for mechanical stimulus. Expect improved recovery (which allows higher training frequency), modest lean-mass preservation during fat loss, and subtle 'fullness' in the first 2-3 weeks (glycogen and water retention). For dramatic physique changes, you need training, nutrition, and sleep on top of the peptide — the peptide optimizes baseline physiology, not outcomes by itself.
Do I have to inject on an empty stomach?
Yes — this is the single most important dosing detail. Postprandial somatostatin (the GH-inhibiting hormone) blunts the GH response by 30-70%. Inject in a fasted state: at least 2 hours after the last carbohydrate-containing meal, and before eating afterward. Pre-bed dosing works because most users have a 2-4 hour gap between dinner and bed. AM dosing works because it's pre-breakfast. Taking MOD-GRF 1-29 after a protein shake or with food substantially reduces its effect — it's not dangerous, just wasteful.
Is CJC-1295 legal?
In the United States, CJC-1295 is not FDA-approved and is not a controlled substance. It is legally available through compounding pharmacies with a prescription for specific patient use. Research-grade peptides are sold for 'research use only' and are not intended for human use — this is the regulatory gray zone that most biohackers operate in. CJC-1295 (and ipamorelin) were removed from the FDA's compoundable bulk substances list in 2023, which has limited prescription availability. WADA prohibits GH-releasing peptides at all times for competitive athletes. Check your jurisdiction's current regulations.
How soon will I notice effects?
Acute effects (flushing, vivid dreams, sleep quality) within 1-2 weeks. Subjective energy and recovery improvements usually by week 3-4. Measurable IGF-1 rise by week 4-6 (this is why we test at week 8-12). Body composition changes (if they happen) by month 2-3. If you feel nothing by week 6-8 with appropriate timing, check: vendor COA (is the peptide real?), reconstitution technique, meal timing, baseline IGF-1 (if already high-normal, there's little room to rise). The flushing sensation at injection is usually the first signal that the peptide is biologically active.
Can I use CJC-1295 if I've had cancer in the past?
Active malignancy is an absolute contraindication. History of cancer within 5 years is a relative contraindication — the risk/benefit calculation depends on cancer type, time since treatment, and current surveillance. Hormone-sensitive cancers (breast, prostate, endometrial) warrant particular caution because IGF-1 is epidemiologically associated with their risk. This is a conversation to have with your oncologist, not to self-decide. Most longevity-focused clinicians recommend at least 5 years of disease-free status before considering GH-axis interventions, with ongoing surveillance thereafter.
Do I need to cycle off?
Not strictly, but many clinicians prefer structured cycling. Sermorelin (the FDA-approved analog with identical receptor activity) has been used continuously for years in pediatric GH deficiency without somatotroph exhaustion. For adults using MOD-GRF 1-29 with ipamorelin, 6-12 month continuous use with monitoring is reasonable. Conservative cycling patterns include 5-days-on/2-off weekly or 3-months-on/1-month-off quarterly. The main reasons to cycle are: preserve pulsatile physiology, reduce receptor desensitization risk, and manage IGF-1 drift upward. An annual break of 4-6 weeks is a reasonable default.
Will my body stop making its own growth hormone?
No — this is one of the advantages of secretagogues vs exogenous rhGH. MOD-GRF 1-29 stimulates the pituitary to release endogenous GH; it does not replace it. Negative feedback remains intact (somatostatin can still suppress GH when appropriate), and the pulsatile dosing pattern does not desensitize somatotroph receptors in the way that continuous CJC-1295 with DAC might. When you stop, the axis returns to baseline within days to weeks. Contrast this with exogenous rhGH, which does suppress endogenous GH production through negative feedback.
Research Tools
Related Compounds
View AllCJC-1295 with DAC
Growth Hormone / IGF-1 AxisPhase 2CJC-1295 with DAC (Drug Affinity Complex) is a modified form of CJC-1295 that incorporates a maleimidopropionic acid (MPA) reactive group at the C-terminus.
GHRP-2
Growth Hormone / IGF-1 AxisPhase 2GHRP-2 (growth hormone-releasing peptide-2), also known as pralmorelin and KP-102, is a synthetic hexapeptide growth hormone secretagogue that was among the first GHRPs developed in the seminal research of Cyril Bowers and colleagues at Tulane University in the late 1980s and early 1990s.
GHRP-6
Growth Hormone / IGF-1 AxisPhase 2GHRP-6 (growth hormone-releasing peptide-6) is a synthetic hexapeptide with the sequence His-D-Trp-Ala-Trp-D-Phe-Lys-NH2 that binds the ghrelin receptor (GHS-R1a) to stimulate endogenous growth hormone release.
Hexarelin
Growth Hormone / IGF-1 AxisPhase 2Hexarelin (also called examorelin) is a potent synthetic hexapeptide growth hormone secretagogue with the sequence His-D-2-methyl-Trp-Ala-Trp-D-Phe-Lys-NH2.
IGF-1 LR3
Growth Hormone / IGF-1 AxisPhase 2IGF-1 LR3 (Long R3 IGF-1) is a synthetic analog of human insulin-like growth factor 1 modified at two positions to dramatically extend its serum half-life and amplify its tissue bioactivity compared to native IGF-1.
Ipamorelin
Growth Hormone / IGF-1 AxisPreclinicalIpamorelin is a selective pentapeptide ghrelin receptor (GHS-R1a) agonist — one of the most studied growth hormone secretagogues (GHS) in the biohacking community and the modern companion to CJC-1295 / MOD-GRF 1-29.
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