GH Axis Research | GHRH vs GHSR
CJC-1295 vs Ipamorelin — GHRH Analog vs GHSR Agonist
A research-focused comparison of CJC-1295 (No DAC, GHRH analog) and Ipamorelin (selective GHSR-1a agonist) — two complementary GH axis research peptides that target distinct receptors in the growth hormone secretion pathway and are frequently co-studied in combination protocols.
CJC-1295 vs Ipamorelin: Complementary GH Axis Mechanisms
CJC-1295 (No DAC) and Ipamorelin are among the most co-studied peptides in growth hormone axis research precisely because they target different receptors in the same regulatory pathway. CJC-1295 is a GHRH analog acting at the GHRH receptor (GHRHR) on pituitary somatotrophs. Ipamorelin is a selective GHSR-1a agonist (growth hormone secretagogue receptor), acting as a ghrelin mimetic. These distinct receptor targets mean the two compounds are studied together for synergistic GH axis co-activation protocols.
Receptor Mechanism Comparison
| Parameter | CJC-1295 (No DAC) | Ipamorelin |
|---|---|---|
| Receptor target | GHRHR (GHRH receptor) | GHSR-1a (ghrelin receptor) |
| Peptide class | GHRH analog | GHS (growth hormone secretagogue) |
| Sequence length | 29 amino acids | 5 amino acids (pentapeptide) |
| MW | 3,367.9 g/mol | 711.9 g/mol |
| Half-life | ~30 min (No DAC) | ~2 hours |
| ACTH/cortisol effects | Minimal | Highly selective — minimal |
| GH pulse type | Pulsatile (mimics GHRH) | Pulsatile (mimics ghrelin) |
| Combination synergy | ✓ Excellent with GHSR agonists | ✓ Excellent with GHRH analogs |
CJC-1295 (No DAC) Mechanism
CJC-1295 (No DAC), also referred to as Mod GRF(1-29), is a 29-amino-acid modified analog of growth hormone-releasing hormone (GHRH). It binds and activates the GHRH receptor on anterior pituitary somatotrophs, stimulating growth hormone release. Without the Drug Affinity Complex (DAC) modification, the half-life is approximately 30 minutes — designed to mimic the natural pulsatile rhythm of GHRH secretion rather than produce sustained, non-physiological GH elevation. This makes it valuable for pulsatile GH secretion modeling and rhythm research.
Ipamorelin Mechanism
Ipamorelin is a synthetic pentapeptide GHS (growth hormone secretagogue) that selectively agonizes GHSR-1a (the ghrelin receptor) on pituitary somatotrophs and hypothalamic neurons. Unlike earlier non-selective GHS compounds (GHRP-2, GHRP-6, hexarelin), ipamorelin does not significantly stimulate ACTH, cortisol, or prolactin release — a receptor selectivity profile that makes it the preferred tool compound for clean GH secretagogue studies without confounding hormonal side effects.
Combination Protocol Research
The CJC-1295 + Ipamorelin combination is one of the most studied GH axis dual-peptide protocols in research because the two compounds activate GH release through distinct, synergistic mechanisms. GHRH receptor activation (CJC-1295) and GHSR agonism (Ipamorelin) work through different intracellular pathways — Gαs/cAMP for GHRHR and Gαq/IP3 for GHSR — and their concurrent activation produces a synergistic amplification of GH pulse amplitude that exceeds either compound alone.
Research note: The combination is used to model the physiological synergy between the two natural GH secretagogue inputs (GHRH and ghrelin) that control pulsatile GH release. Researchers studying GH axis regulation, pituitary pharmacology, or IGF-1 pathway downstream signaling frequently employ both compounds in parallel protocols.
CJC-1295 & Ipamorelin Research Peptides
Related GH Axis Research
- GH Axis Peptides Catalog — Full GH axis research peptide collection
- GH Axis Research Stack — CJC-1295 + Ipamorelin + Tesamorelin bundle
- Research Library — GH axis research guides and protocols
Research Use Only: All compounds referenced on this page are strictly for laboratory and in vitro research purposes only. Not intended for human use, veterinary use, or diagnostic/treatment purposes. OligoPoly Labs sells research-grade peptides exclusively to qualified researchers.
Research Compounds Referenced in This Guide
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