Ipamorelin is a synthetic pentapeptide (five amino acids) classified as a growth hormone secretagogue (GHS). It is one of the most selective GHS peptides studied to date, meaning it stimulates growth hormone release from the pituitary gland with minimal effect on other hormones such as cortisol, prolactin, or ACTH. This selectivity has made it a popular choice in growth hormone research.
How Ipamorelin Works
Ipamorelin acts as a ghrelin mimetic — it binds to the growth hormone secretagogue receptor (GHS-R) in the pituitary gland, triggering a pulse of growth hormone release. Unlike some other GHS peptides, Ipamorelin does not significantly increase appetite (a common side effect of ghrelin receptor activation) at the doses typically used in research protocols.
Ipamorelin vs Other GHS Peptides
| Peptide | GH Release | Cortisol Impact | Appetite Effect | Selectivity |
|---|---|---|---|---|
| Ipamorelin | Moderate | Minimal | Minimal | High |
| GHRP-2 | Strong | Moderate | Strong | Moderate |
| GHRP-6 | Strong | Moderate | Very strong | Low |
| Hexarelin | Very strong | Moderate | Moderate | Moderate |
Ipamorelin's high selectivity makes it particularly useful in studies where researchers want to isolate growth hormone effects without the confounding variables introduced by cortisol elevation or appetite changes.
Combination Research
Ipamorelin is most commonly studied in combination with growth hormone-releasing hormone (GHRH) analogues. The rationale is synergistic: GHRH analogues stimulate GH synthesis, while Ipamorelin triggers its release.
- CJC-1295 (no DAC) + Ipamorelin — the most popular combination, providing a sustained GH pulse with high selectivity
- Tesamorelin + Ipamorelin — Tesamorelin is a stabilised GHRH analogue with a longer track record in clinical research
- Sermorelin + Ipamorelin — a shorter-acting combination that more closely mimics natural pulsatile GH release
Research Context
The body of published research on Ipamorelin spans several areas including body composition changes in animal models, bone density research, and gut motility studies. It was originally developed by Novo Nordisk and has been the subject of multiple Phase I and Phase II clinical trials, making it one of the better-characterised GHS peptides in terms of safety and pharmacokinetic data.
Read our full Ipamorelin Research Guide
Reconstitution and Storage
Ipamorelin is supplied as a lyophilised powder and should be reconstituted with bacteriostatic water. Store at 2-8°C after reconstitution. See our reconstitution guide for step-by-step instructions and use the dosage calculator for volume calculations.
All Ipamorelin from Regen Peptides is independently tested at ≥99% purity. View our COAs.
This article is for educational and informational purposes only. All peptides sold by Regen Peptides are strictly for in-vitro research and laboratory use. Not for human consumption.
