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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

GHRP-6 — pharmacology

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

Document identifier
CEI-MN-027/2
Series
Compound monograph
Version
4.0
Published
21 Nov 2024
Last reviewed
21 Sep 2025
Next review
21 Sep 2027
Identifier
10.71829/cei.mono.27
Certainty
Very low
Cycle
2024 Q4

§2Pharmacology

§2.1Molecular targets

Table 2. Molecular targets recorded for GHRP-6, with the character of the interaction and the potency where the Institute holds it.

TargetInteractionNote
Growth hormone secretagogue receptor (GHSR-1a)AgonistThe original synthetic ligand for this receptor, characterised before the endogenous ligand ghrelin was identified

§2.2Mechanism of action

Ghrelin receptor agonism with pronounced growth-hormone release, marked appetite stimulation, and concomitant elevation of cortisol and prolactin. Its historical importance is substantial — it was the pharmacological tool that led to the discovery of the ghrelin receptor and subsequently of ghrelin itself — but its selectivity profile makes it the least attractive member of the class for any practical purpose.[1,2]

§2.3Pharmacokinetics

Terminal half-life
≈20 min
Time to maximum concentration
≈15 min
Volume of distribution
not published
Plasma protein binding
not published
Clearance
not published
Bioavailability
not published

Rapid proteolytic degradation. Tachyphylaxis with continued dosing is documented.

Reconstructed plasma concentration–time profilePlasma concentration plotted against time after dosing, reconstructed from published pharmacokinetic parameters.0.00.20.40.60.801122Time after first dose (hours)Relative concentrationt max ≈ 0 ht½ ≈ 1 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. Thevis M, Thomas A, Schänzer W. Detecting peptidic drugs, drug candidates and analogs in sports doping: current status and future directions. Expert Review of Proteomics 2019;11(6):663–673. doi:10.1586/14789450.2014.965158

Identifiers are reproduced only where the Institute holds them. Where a digital object identifier or PubMed identifier is not shown, the Institute has recorded the journal and year and has not constructed an identifier.

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