Ipamorelin is a pentapeptide widely studied in GH-axis research for receptor-selective secretagogue behavior. Unlike broad secretagogue profiles, ipamorelin is commonly investigated for cleaner GHSR-1a targeting and predictable pulse-oriented GH signaling. It is frequently compared with, or paired alongside, GHRH analogs such as sermorelin or CJC variants in protocols focused on pulse architecture and downstream IGF-1 trends.
Technical Specifications
CAS Number
170851-70-4
Molecular Formula
C38H49N9O5
Molecular Weight
711.85 g/mol
Amino Acids
5
Sequence
Aib-His-D-2-Nal-D-Phe-Lys-NH2
Purity
>=99% (HPLC)
Appearance
White lyophilized powder
Salt Form
Acetate
Solubility
Soluble in water
Storage
-20C lyophilized, 2-8C reconstituted
Origin & Discovery
Ipamorelin was developed as a selective growth-hormone secretagogue peptide to stimulate GH release through the ghrelin receptor (GHSR-1a) with reduced off-target endocrine activity relative to earlier secretagogue classes.
Mechanism of Action
Ipamorelin primarily acts as a ghrelin receptor (GHSR-1a) agonist.
GHSR-1a Activation: Binding at pituitary and hypothalamic ghrelin receptors promotes GH release in a pulsatile manner.
Pulse-Oriented Signaling: The compound is often studied for temporal GH pulse support rather than sustained baseline elevation.
Axis-Combination Logic: Because ipamorelin enters through the ghrelin pathway, it is frequently used in combination designs with GHRH analogs that signal through different receptor pathways.
Comparator Importance: Its value in research is often less about absolute GH output alone and more about pathway selectivity, timing behavior, and protocol reproducibility.
Selective Secretagogue Characterization
Early pharmacology work positioned ipamorelin as a receptor-selective GH secretagogue candidate with favorable profile characteristics for pulse-oriented GH-axis studies. Investigators used it to model ghrelin-pathway stimulation without relying on broad non-specific endocrine triggers.
Citations
Raun K, et al. (1998) "Ipamorelin, the first selective growth hormone secretagogue." Eur J Endocrinol, 139(5), 552-561.
Pituitary Signaling and Pulse Research
Ipamorelin has been studied in both preclinical and translational settings to evaluate GH pulse induction and downstream endocrine trends. A central use-case is understanding how ghrelin-pathway signaling can be timed and compared against GHRH-driven stimulation frameworks.
Citations
Pietra C, et al. (2001) "Growth hormone secretagogue receptor-mediated effects of ipamorelin." J Endocrinol Invest, 24(10), RC41-RC45.
Frequently Asked Questions
What is ipamorelin?▼
Ipamorelin is a synthetic pentapeptide studied as a selective ghrelin receptor (GHSR-1a) agonist for growth-hormone-axis signaling research.
How is ipamorelin different from sermorelin?▼
Ipamorelin is primarily a GHSR agonist, while sermorelin is a GHRH analog. They stimulate GH-axis pathways from different receptor entry points.
Can ipamorelin be studied with CJC-1295?▼
Yes. Combination protocols are common because ghrelin-pathway and GHRH-pathway signals can be complementary in pulse-design studies.