What Is Ipamorelin?
Ipamorelin is a synthetic pentapeptide growth hormone releasing peptide (GHRP) and selective ghrelin receptor agonist developed by Novo Nordisk in the late 1990s. It stimulates growth hormone secretion from the anterior pituitary through the GHSR-1a (growth hormone secretagogue receptor) pathway, but with a highly selective profile that distinguishes it from earlier GHRPs — notably its minimal effect on cortisol and prolactin at research doses, which made it a preferred research tool for isolated GH secretion studies.
Ipamorelin is frequently studied in combination with CJC-1295 Without DAC (Modified GRF 1-29), a GHRH analogue that acts on the complementary GHRH receptor pathway. This dual-receptor approach produces synergistic GH secretion in research models by simultaneously engaging both the GHRP and GHRH receptor systems.
Ipamorelin Mechanism of Action
Ipamorelin acts as a selective agonist at the GHSR-1a receptor (ghrelin receptor) in the pituitary and hypothalamus:
- GH pulse amplification: Enhances the amplitude of natural GH pulses rather than producing continuous elevation, preserving physiological pulsatility
- Cortisol selectivity: Unlike GHRP-2 and GHRP-6, ipamorelin does not significantly stimulate ACTH or cortisol release at research doses — a key selectivity advantage in metabolic and body composition research models
- Prolactin sparing: Minimal prolactin stimulation compared to earlier GHRP compounds, reducing confounds in reproductive and endocrine research models
- Appetite effects: As a ghrelin receptor agonist, ipamorelin may influence appetite-related signaling pathways, relevant to metabolic research applications
Ipamorelin Research Data
Ipamorelin has been studied across multiple research contexts with published preclinical and limited clinical data:
- GH secretion (original Novo Nordisk studies): Demonstrated robust dose-dependent GH release in both rodent models and human Phase 1 studies, with a favorable safety profile and high selectivity versus other pituitary hormones
- Bone density research: Preclinical studies in ovariectomized rats demonstrated ipamorelin preserved bone mineral density and increased bone formation markers, supporting research interest in osteoporosis models
- Gastrointestinal motility: A published clinical trial studied ipamorelin for postoperative ileus (bowel motility disorder), demonstrating accelerated gastrointestinal transit compared to placebo — an unexpected research direction for a GHRP compound
- Body composition: Animal studies consistently show increased lean mass and reduced adiposity with ipamorelin, proportionate to GH elevation
Ipamorelin Dosage Reference
| Research Context | Dose from Published Data | Route |
|---|---|---|
| GH secretion (human Phase 1) | 1–3 mcg/kg | IV bolus |
| Postoperative ileus trial | 30–200 mcg doses | IV infusion |
| Bone density (rodent) | 40–200 mcg/kg/day | Subcutaneous |
| Body composition (rodent) | 200–300 mcg/kg | Subcutaneous |
Published study data provided for research reference only. Not dosing guidance for human use.
Side Effects from Research Data
Ipamorelin has demonstrated a favorable safety profile in published studies:
- Mild flushing or warmth at injection site in human Phase 1 studies
- Transient headache reported by some subjects in clinical studies
- Possible water retention at higher doses (GH-mediated)
- No significant cortisol, ACTH, or prolactin elevation at standard research doses — a key safety advantage over earlier GHRPs
Ipamorelin vs. GHRP-2 — Research Comparison
| Parameter | Ipamorelin | GHRP-2 |
|---|---|---|
| Receptor target | GHSR-1a (selective) | GHSR-1a (less selective) |
| Cortisol stimulation | Minimal | Significant |
| Prolactin stimulation | Minimal | Moderate |
| GH release potency | Moderate-high | High |
| Research selectivity | High — preferred for clean GH studies | Lower — more confounders |
Where to Buy Ipamorelin for Research
Ipamorelin’s selectivity profile makes purity especially important for research validity. Supplier criteria:
- HPLC purity ≥99% with batch certificate
- MS/MS peptide sequence verification
- Third-party independent COA
- Lyophilized format for stability
Core Power Peptides supplies the Ipamorelin / CJC-1295 No DAC 10mg blend at ≥99% purity per component, HPLC and MS/MS verified, with third-party COA available. This dual-compound format supports simultaneous GHRP and GHRH receptor pathway research.
Research Disclaimer: All information on this page is for educational and scientific reference purposes only. Ipamorelin is not approved for human use. This product is sold strictly for in vitro research and laboratory use. Not for human consumption. Not medical advice.