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Research Catalog

Molecular mechanism

Growth hormone secretagogue receptor

A G-protein-coupled receptor distinct from the GHRH receptor. Antagonist profiling reported that ipamorelin releases growth hormone through a GHRP-like receptor rather than through the GHRH receptor, establishing the two pathways as separate.

Type: receptorPublished: 2026-09-04Literature/identifier verification: 2026-08-23

See this target on the receptor map

GHS-R1aGhrelin receptorGHSR

01

Neutral molecular overview

A G-protein-coupled receptor distinct from the GHRH receptor. Antagonist profiling reported that ipamorelin releases growth hormone through a GHRP-like receptor rather than through the GHRH receptor, establishing the two pathways as separate.

02

Target identifiers

Gene symbols
GHSR

03

Related compounds

Compound

Anamorelin

Anamorelin is a nonpeptide small-molecule agonist at the ghrelin receptor, structurally unrelated to the peptide secretagogues that share its target.

Compound

Examorelin (Hexarelin)

Examorelin, widely supplied as hexarelin, is a synthetic hexapeptide growth hormone secretagogue carrying a 2-methylated D-tryptophan.

Compound

Human Octanoyl-Ghrelin

Human octanoyl-ghrelin is the endogenous 28-residue acylated peptide ligand of the ghrelin receptor, carrying an n-octanoyl ester on serine 3.

Compound

GHRP-6

GHRP-6 is a synthetic hexapeptide with a C-terminal amide, characterized as an agonist at the growth hormone secretagogue receptor.

Compound

Ipamorelin

Ipamorelin is a synthetic pentapeptide with a C-terminal amide, characterized in its original report as a growth hormone secretagogue acting through a GHRP-like receptor rather than the GHRH receptor.

Compound

Macimorelin

Macimorelin is a gem-diamino peptidomimetic agonist at the ghrelin receptor.

Compound

Pralmorelin (GHRP-2)

Pralmorelin is a synthetic hexapeptide growth hormone secretagogue acting at the ghrelin receptor, containing three D-configured residues and a naphthylalanine substitution.

04

Related mechanisms

receptor

GHRH receptor

A class B G-protein-coupled receptor expressed on anterior pituitary somatotrophs. Synthetic growth hormone-releasing factor analogs are characterized by their activity at this receptor.

receptor

CD36 scavenger receptor

A multifunctional scavenger receptor, distinct from the growth hormone secretagogue receptor, reported as a binding target for certain synthetic secretagogue peptides. It is recorded separately here precisely because collapsing it into the ghrelin-receptor mechanism would erase the finding that these compounds are not pharmacologically interchangeable.

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Verified bibliography

  1. Reference 1

    Ipamorelin, the first selective growth hormone secretagogue.

    Raun K, Hansen BS, Johansen NL, Thøgersen H, Madsen K, Ankersen M, Andersen PH

    European journal of endocrinology · 1998-11 · Journal Article

    current
    PMID 9849822DOI 10.1530/eje.0.1390552IpamorelinGHRP-6GHS-R1a

  2. Reference 2

    Ghrelin and glucose homeostasis.

    Delhanty PJ, van der Lely AJ

    Peptides · 2011-03-21 · Review

    current
    PMID 21396419DOI 10.1016/j.peptides.2011.03.001IpamorelinGHS-R1a

  3. Reference 3

    Structure of an antagonist-bound ghrelin receptor reveals possible ghrelin recognition mode.

    Shiimura Y, Horita S, Hamamoto A, Asada H, Hirata K, Tanaka M, Mori K, Uemura T, Kobayashi T, Iwata S, Kojima M

    Nature communications · 2020-08-19 · Journal Article

    current
    PMID 32814772PMC7438500DOI 10.1038/s41467-020-17554-1IpamorelinGHRP-6GHS-R1a

  4. Reference 4

    Growth hormone secretagogue receptor family members and ligands.

    Smith RG, Leonard R, Bailey AR, Palyha O, Feighner S, Tan C, Mckee KK, Pong SS, Griffin P, Howard A

    Endocrine · 2001-02 · Review

    current
    PMID 11322507DOI 10.1385/ENDO:14:1:009GHRP-6IpamorelinGHS-R1a

  5. Reference 5

    Highly potent growth hormone secretagogues: hybrids of NN703 and ipamorelin.

    Hansen TK, Ankersen M, Raun K, Hansen BS

    Bioorganic & medicinal chemistry letters · 2001-07-23 · Journal Article

    current
    PMID 11459660DOI 10.1016/s0960-894x(01)00345-6IpamorelinGHS-R1a

  6. Reference 6

    Effect of GHRH and GHRP-2 treatment in vitro on GH secretion and levels of GH, pituitary transcription factor-1, GHRH-receptor, GH-secretagogue-receptor and somatostatin receptor mRNAs in ovine pituitary cells.

    Yan M, Hernandez M, Xu R, Chen C

    European journal of endocrinology · 2004-02 · Journal Article

    current
    PMID 14763922DOI 10.1530/eje.0.1500235Pralmorelin (GHRP-2)GHS-R1a

  7. Reference 7

    1H NMR structural analysis of human ghrelin and its six truncated analogs.

    Silva Elipe MV, Bednarek MA, Gao YD

    Biopolymers · 2001-12 · Journal Article

    current
    PMID 11745115DOI 10.1002/1097-0282(200112)59:7<489::aid-bip1054>3.0.co;2-sHuman Octanoyl-GhrelinGHS-R1a

  8. Reference 8

    Ghrelin is a growth-hormone-releasing acylated peptide from stomach.

    Kojima M, Hosoda H, Date Y, Nakazato M, Matsuo H, Kangawa K

    Nature · 1999-12-09 · Journal Article

    current
    PMID 10604470DOI 10.1038/45230Human Octanoyl-GhrelinGHS-R1a

  9. Reference 9

    Molecular recognition of an acyl-peptide hormone and activation of ghrelin receptor.

    Wang Y, Guo S, Zhuang Y, Yun Y, Xu P, He X, Guo J, Yin W, Xu HE, Xie X, Jiang Y

    Nature communications · 2021-08-20 · Journal Article

    current
    PMID 34417468PMC8379176DOI 10.1038/s41467-021-25364-2Human Octanoyl-GhrelinMacimorelinGHRP-6GHS-R1a

  10. Reference 10

    In vitro pharmacological characterization of growth hormone secretagogue receptor ligands using the dynamic mass redistribution and calcium mobilization assays.

    Sturaro C, Ruzza C, Ferrari F, Pola P, Argentieri M, Frezza A, Marzola E, Bettegazzi B, Cattaneo S, Pietra C, Malfacini D, Calò G

    European journal of pharmacology · 2024-08-10 · Journal Article

    current
    PMID 39128804DOI 10.1016/j.ejphar.2024.176880Human Octanoyl-GhrelinAnamorelinGHS-R1a

  11. Reference 11

    New active series of growth hormone secretagogues.

    Guerlavais V, Boeglin D, Mousseaux D, Oiry C, Heitz A, Deghenghi R, Locatelli V, Torsello A, Ghé C, Catapano F, Muccioli G, Galleyrand JC, Fehrentz JA, Martinez J

    Journal of medicinal chemistry · 2003-03-27 · Journal Article

    current
    PMID 12646029DOI 10.1021/jm020985qMacimorelinGHS-R1a

  12. Reference 12

    Molecular recognition of two approved drugs Macimorelin and Anamorelin by the growth hormone secretagogue receptor.

    Wang RL, Sun J, Liu H, Guo SM, Zhang Y, Hu W, Wang J, Liu H, Zhuang YW, Jiang Y, Xie X, Xu HE, Wang Y

    Acta pharmacologica Sinica · 2025-06-20 · Journal Article

    current
    PMID 40542284PMC12552520DOI 10.1038/s41401-025-01606-7MacimorelinAnamorelinGHS-R1a

  13. Reference 13

    The structure and function of the ghrelin receptor coding for drug actions.

    Shiimura Y, Im D, Tany R, Asada H, Kise R, Kurumiya E, Wakasugi-Masuho H, Yasuda S, Matsui K, Kishikawa JI, Kato T, Murata T, Kojima M, Iwata S, Masuho I

    Nature structural & molecular biology · 2025-01-20 · Journal Article

    current
    PMID 39833471DOI 10.1038/s41594-024-01481-6AnamorelinGHS-R1a

Study models of these references

What kind of experiment each cited paper reports, taken from its abstract unless marked. Not a summary of results.

ReferenceStudy models
Raun K et al. 1998Study models reported: in vitro; animal (rat, swine) · from the abstract
Delhanty PJ et al. 2011Review article
Shiimura Y et al. 2020Study models reported: in vitro · from the abstract
Smith RG et al. 2001Review article
Hansen TK et al. 2001Study models reported: in vitro; animal (pig) · from the abstract
Yan M et al. 2004Study models reported: in vitro · from the abstract
Silva Elipe MV et al. 2001Chemical, structural or analytical study; no biological model reported
Kojima M et al. 1999Study models reported: in vitro; in vivo (subject not stated) · from the abstract
Wang Y et al. 2021Study models reported: in vitro · from the abstract
Sturaro C et al. 2024Study models reported: in vitro · from the abstract
Guerlavais V et al. 2003Study models reported: in vitro; animal (rat, beagle dog) · from the abstract
Wang RL et al. 2025Study models reported: in vitro · from the abstract
Shiimura Y et al. 2025Study models reported: in vitro · from the abstract

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Related glossary terms

AgonistLigandG-protein-coupled receptor

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Related Purely Peptides research articles

No existing Research Article is mapped to this mechanism seed record.