Selective pentapeptide ghrelin receptor (GHSR-1a) agonist. Studied for clean pulsatile growth-hormone release without significant cortisol or prolactin co-elevation in preclinical models.
Ipamorelin is a synthetic pentapeptide developed by Novo Nordisk in the late 1990s as a selective ghrelin-mimetic. Unlike GHRP-2 and GHRP-6, it binds GHSR-1a with high specificity without measurable affinity for receptors that mediate prolactin, cortisol, or aldosterone release.
The compact pentapeptide engages the GHSR-1a transmembrane domain with selective high affinity. The Aib (2-aminoisobutyric acid) residue enhances proteolytic resistance.
Gq/11 → PLCβ activation → IP3 release triggers ER Ca²⁺ mobilization. The Ca²⁺ pulse drives somatotroph degranulation and rapid GH release into the portal circulation.
Ipamorelin and GHRH activate independent receptor systems (GHSR-1a vs GHRHR) producing synergistic — rather than additive — GH pulse amplitude when administered concurrently in research protocols.
In rodent and canine models, Ipamorelin produces dose-dependent GH peaks at 100–300 mcg subcutaneous doses with peak elevation at 30–60 minutes post-administration. Repeated daily administration over weeks does not desensitise the GHSR-1a receptor in published protocols.
Refs: Raun K et al., Eur J Endocrinol (1998); Andersen NH et al., Mol Endocrinol (2001)
Chronic Ipamorelin administration in juvenile rat models accelerated longitudinal bone growth, increased femoral cortical bone density, and modulated body-composition parameters via IGF-1-dependent pathways. Adult models show subtler but consistent effects on lean mass and visceral adiposity.
Refs: Svensson J et al., J Endocrinol (2000); Aagaard NK et al., JCEM (2014)
Each batch is independently tested by a third-party ISO-accredited laboratory. The analysis below reflects Batch AV-2025-IPA-029, tested 10 February 2025.
| Test Parameter | Method | Specification | Result | Status |
|---|---|---|---|---|
| Identity (sequence) | ESI-MS / MS-MS | Matches theoretical m/z | Confirmed (711.9 Da) | PASS |
| Purity (HPLC) | RP-HPLC C18, 210nm | ≥98.0% | 99.4% | PASS |
| Water content | Karl Fischer | ≤8.0% | 5.4% | PASS |
| Heavy metals | ICP-MS (EPA 200.8) | ≤10 ppm | <2 ppm | PASS |
| Bacterial endotoxins | LAL chromogenic | ≤10 EU/mg | <1 EU/mg | PASS |
| Form | Temperature | Duration |
|---|---|---|
| Lyophilised powder | −20°C (preferred) or 2–8°C | 24 months / 12 months |
| Reconstituted (BAC water) | 2–8°C | ≤28 days |
| Reconstituted (saline) | 2–8°C | ≤7 days |
Wipe vial with 70% IPA, allow to dry.
For 5 mg vial, add 2 mL BAC water → 2.5 mg/mL stock. Inject slowly along the inner vial wall.
Swirl gently — never vortex. Ipamorelin is highly soluble; dissolution typically complete within 30–60 seconds.
Refrigerate at 2–8°C. Aliquot for repeated use to minimise membrane penetration of stock vial.
Ipamorelin is more selective than GHRP-2 and GHRP-6, both of which elevate cortisol and prolactin in addition to GH. GHRP-6 also induces marked hunger via ghrelin's appetite axis. Ipamorelin avoids these effects while maintaining comparable GH pulse amplitude — making it the preferred GHRP for isolated GH-axis research.
Ipamorelin (GHSR-1a agonist) and CJC-1295 (GHRH analogue) act on different pituitary receptors via independent signal cascades, producing synergistic rather than additive GH release. This combination is widely used in preclinical GH-axis studies to maximise pulse amplitude while preserving natural pulse architecture.
Published rodent studies of repeated daily administration over 4–8 weeks did not demonstrate functional receptor desensitisation — peak GH responses were preserved through the study duration. Some protocols employ pulse-cycling (5 days on, 2 off) to model physiological ghrelin patterns, but receptor maintenance does not appear to require it.
Most published protocols administer Ipamorelin in a fasted state, typically pre-sleep or pre-exercise, to align with endogenous GH pulse peaks and avoid blunting from somatostatin tone. Glucose and free fatty acid elevation can suppress GH response, so insulin and meal timing matter for protocol design.
Independently verified by third-party ISO-accredited laboratory. COA available on request.
View Ipamorelin in Store → Reconstitution Protocol Guide