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Compound Evidence InstituteEvidence synthesis · established 2023Graded assessments of compounds, trials, methods and supply
Document set current to 30 July 2026
Compound monograph · §2

Ipamorelin — pharmacology

Molecular targets, mechanism of action, pharmacokinetics and interactions as characterised in humans.

Document identifier
CEI-MN-024/2
Series
Compound monograph
Version
3.3
Published
20 Feb 2026
Last reviewed
20 Feb 2026
Next review
20 Feb 2028
Identifier
10.71829/cei.mono.24
Certainty
Low
Cycle
2026 Q1

§2Pharmacology

§2.1Molecular targets

Table 2. Molecular targets recorded for Ipamorelin, with the character of the interaction and the potency where the Institute holds it.

TargetInteractionNote
Growth hormone secretagogue receptor (GHSR-1a, ghrelin receptor)AgonistSelective for growth-hormone release without the adrenocorticotropin, cortisol or prolactin elevation seen with earlier secretagogues such as GHRP-6

§2.2Mechanism of action

Ipamorelin activates the ghrelin receptor on pituitary somatotrophs, producing growth-hormone release through a pathway distinct from and complementary to GHRH receptor signalling. Its defining pharmacological characteristic, established in the original preclinical work, is selectivity: unlike GHRP-6 and hexarelin it does not meaningfully raise cortisol or prolactin, and unlike ghrelin itself it does not stimulate appetite at growth-hormone-releasing doses.[1,2]

§2.3Pharmacokinetics

Terminal half-life
≈2 h
Time to maximum concentration
not reliably published in humans
Volume of distribution
not published
Plasma protein binding
not published
Clearance
not published
Bioavailability
not published

Assumed proteolytic and renal. Human pharmacokinetic data are sparse.

Reconstructed plasma concentration–time profilePlasma concentration plotted against time after dosing, reconstructed from published pharmacokinetic parameters.0.00.20.40.602468Time after first dose (hours)Relative concentrationt max ≈ 1 ht½ ≈ 2 h
Modelled profileSimulated observationsDose administration
Figure 2. Illustrative. Plasma concentration–time profile reconstructed by the Institute from the published half-life and time-to-maximum-concentration parameters using a one-compartment model with first-order absorption. The curve is not digitised from a published figure and its vertical scale is relative. It is published to convey the shape of the profile and the approach to steady state, not to supply a concentration at any time point.

§2.4Interactions

  • Not characterised

References cited on this page

References are numbered in order of first citation in this document. Each superscript in the text links to its entry below.

  1. Raun K, Hansen BS, Johansen NL, Thøgersen H, Madsen K, Ankersen M, Andersen PH. Ipamorelin, the first selective growth hormone secretagogue. European Journal of Endocrinology 1998;139(5):552–561. doi:10.1530/eje.0.1390552 · PMID 9849822
  2. Teichman SL, Neale A, Lawrence B, Gagnon C, Castaigne JP, Frohman LA. Prolonged stimulation of growth hormone (GH) and insulin-like growth factor I secretion by CJC-1295, a long-acting analog of GH-releasing hormone, in healthy adults. Journal of Clinical Endocrinology & Metabolism 2006;91(3):799–805. doi:10.1210/jc.2005-1536 · PMID 16352683

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