Ipamorelin
Also known as NNC 26-0161
Ipamorelin is a selective ghrelin-receptor pentapeptide studied as a GH secretagogue. A research profile focused on why 'selective' is the word that defines it against the older GHRPs.
Ipamorelin belongs to the other branch of this product family. Where CJC-1295, sermorelin and tesamorelin are GHRH analogs, ipamorelin is a ghrelin mimetic — it works through the growth-hormone secretagogue receptor, not the GHRH receptor. That mechanistic split is the single most useful thing to understand about the whole cluster.
The word that follows ipamorelin around the literature is 'selective,' and this page is largely about what that means. As always here: research contexts and chemistry only, no outcomes or dosing.
A short synthetic pentapeptide built around non-natural residues (including aminoisobutyric acid and a D-2-naphthylalanine), with an amidated C-terminus. It is a selective agonist of the growth-hormone secretagogue receptor (GHS-R), the same receptor the hormone ghrelin acts on — a different target from the GHRH analogs.
A ghrelin mimetic, not a GHRH analog
Ghrelin is the hormone best known for hunger signaling, but it also drives growth-hormone release through its own receptor, GHS-R. Ipamorelin is a synthetic agonist of that receptor — a 'secretagogue' — which places it alongside GHRP-2, GHRP-6, hexarelin and the non-peptide MK-677, and apart from the GHRH-analog group.
Because the two receptor systems are separate, researchers frequently study a secretagogue like ipamorelin together with a GHRH analog. Each represents one of the two inputs to the pituitary.
Why selectivity is the headline
The earlier growth-hormone-releasing peptides were effective GHS-R agonists but not clean ones — in research they were noted for also nudging other pituitary outputs such as ACTH, cortisol and prolactin. Ipamorelin was developed and is described in the literature as a notably more selective agonist, associated in study models with a narrower profile than the first-generation GHRPs.
That reputation for selectivity is why ipamorelin, rather than GHRP-6, is the secretagogue most often reached for in the popular research pairings — it is the reason 'CJC-1295 / ipamorelin' became the canonical combination rather than 'CJC-1295 / GHRP-6.'
Structure and identification
Ipamorelin is only five residues long, but several are non-natural — the sequence includes aminoisobutyric acid and a D-configured naphthylalanine, and the C-terminus is amidated. That means it will not resolve to a tidy string of standard amino-acid codes, and a certificate of analysis is read by mass and HPLC purity rather than by a familiar residue list.
A clean single HPLC peak and a mass matching the pentapeptide are the basic checks; every lot should be tied to its own batch certificate.
These are research areas the compound is associated with in the literature — not medical claims or intended uses.
Handling & storage
Supplied lyophilized. Stored sealed and cold; reconstituted with bacteriostatic water only as a protocol requires, then refrigerated. Handle per accepted laboratory practice.
Verify a certificate by lot →Common questions
No. Ipamorelin is a ghrelin mimetic — it acts on the growth-hormone secretagogue receptor (GHS-R), a different target from the GHRH receptor used by sermorelin, tesamorelin and CJC-1295.
In research models it is associated with a narrower pituitary profile than the older GHRPs, which were noted for also affecting outputs such as ACTH, cortisol and prolactin. That selectivity is its defining characteristic.
The two act on different receptors — GHS-R for ipamorelin, the GHRH receptor for CJC-1295 — so they are studied together as complementary inputs to the growth-hormone axis.
This monograph is a research-use reference. It describes composition and the contexts in which the compound has been studied — it is not medical advice, a description of effects, or a recommendation for use. Sold strictly for laboratory and research use; not for human or animal consumption.