Ipamorelin Research Guide: Selective GHRP Mechanism & Half-Life
Ipamorelin is a pentapeptide GHRP prized in research for its selective growth-hormone release without cortisol or prolactin spikes.
Mechanism and selectivity
Ipamorelin's clinical interest stems from its selectivity: unlike other GHRPs, it does not meaningfully activate corticotroph or lactotroph pathways, meaning cortisol and prolactin remain at baseline while GH release is amplified.
In pulsatile GH research it is commonly paired with a GHRH analog such as CJC-1295 (No DAC) — the two act on separate receptors and produce a larger combined GH pulse than either alone.
Sourcing & purity
Research-grade material should be ≥99% pure by HPLC with peptide content confirmed via mass spectrometry. Redline Bio material ships with batch documentation; independent third-party COAs are published on the lab reports page as testing returns.
Compliance reminder
Sold and distributed for laboratory research use only. Not approved by the FDA for human consumption, diagnosis, treatment, or cure of any disease. Researchers are responsible for compliance with all applicable institutional, state, and federal regulations.
Frequently asked questions
What is Ipamorelin?
Ipamorelin is a synthetic pentapeptide (Aib-His-D-2-Nal-D-Phe-Lys-NH₂) that acts as a selective agonist at the ghrelin/growth-hormone-secretagogue receptor (GHSR-1a).
Why is it called 'selective'?
Unlike earlier GHRPs (GHRP-2, GHRP-6, hexarelin), Ipamorelin drives a strong, clean GH pulse without measurable increases in cortisol, ACTH, or prolactin in published research.
What is the half-life?
Roughly 2 hours in published animal pharmacokinetic studies — long enough to sustain a distinct GH pulse but short enough to preserve pulsatility.