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GH Axis · Reference monograph

Growth hormone-releasing peptide-2 (ghrelin-receptor agonist)

Reference compound — not available from Purity Peptides. Shown for research context.

Overview

GHRP-2 is a synthetic hexapeptide belonging to the family of growth hormone-releasing peptides developed in the 1980s and 1990s, before the endogenous hormone ghrelin had been discovered. These peptides were found empirically to release growth hormone through a receptor distinct from that of GHRH; the receptor was later cloned and named GHS-R1a, and ghrelin was identified as its natural ligand.

Under the name pralmorelin, GHRP-2 has been used in Japan as a diagnostic agent for assessing pituitary GH reserve. Research studies have characterised its potent GH-releasing activity, its smaller effects on cortisol and prolactin, and its stimulation of appetite. It has not been approved as a therapy by the FDA or EMA and is prohibited in sport. Our GHRP-2 is a research reference peptide for receptor pharmacology and GH-axis experiments.

Mechanism studied

  1. GHRP-2
  2. GHS-R1a
  3. Pituitary GH release
  4. IGF-1

GHRP-2 binds and activates GHS-R1a, the ghrelin receptor, on pituitary somatotrophs and in the hypothalamus. Receptor activation signals through Gq and phospholipase C, increasing intracellular calcium and triggering GH exocytosis. At the hypothalamic level, ghrelin-receptor agonists enhance GHRH release and functionally oppose somatostatin, which helps explain the synergy observed when they are combined with GHRH analogues. Activation of ghrelin receptors in appetite centres accounts for the hunger signalling observed in research subjects.

Research highlights

  • 01Developed before ghrelin was discovered and helped identify its receptor
  • 02Used in Japan as a diagnostic agent for GH reserve (pralmorelin)
  • 03Potent GH release with modest cortisol and prolactin increases
  • 04Stimulates appetite via central ghrelin-receptor signalling
  • 05Prohibited in sport under WADA class S2

Latest published research

238 papers on PubMed →

  1. Peptides in urology and sexual medicine: clinical effectiveness, dosing, indications, and safety: a narrative review

    Vasylieva V et al. · Sexual medicine reviews · 2026 Sep 30 · PMID 42862021

  2. Differentiating hypothalamic from pituitary adrenal insufficiency: underlying causes and diagnostic utility of the corticotropin-releasing hormone and growth hormone-releasing peptide-2 stimulation tests

    Okada N et al. · Endocrine journal · 2026 Sep 11 · PMID 42732957

  3. The emerging landscape of performance-enhancing peptides modulating GH-IGF1 axis: bridging the gap between clinical evidence and patient self-administration

    Dominikowski A et al. · Frontiers in endocrinology · 2026 · PMID 42395176

  4. Possible Involvement of Hypothalamic Dysfunction in Long COVID Patients Characterized by Delayed Response to Gonadotropin-Releasing Hormone

    Otsuka Y et al. · International journal of molecular sciences · 2026 Jan 14 · PMID 41596479

  5. Diurnal and Daily Variations in Growth Hormone and Growth Hormone Stimulation Test in Male Cynomolgus Monkeys

    Taniguchi Y et al. · In vivo (Athens, Greece) · 2026 Jan-Feb · PMID 41482410

  6. Growth Hormone-Releasing Peptide 2 May Be Associated With Decreased M1 Macrophage Production and Increased Histologic and Biomechanical Tendon-Bone Healing Properties in a Rat Rotator Cuff Tear Model

    Li Y et al. · Arthroscopy : the journal of arthroscopic & related surgery : official publication of the Arthroscopy Association of North America and the International Arthroscopy Association · 2025 Jul · PMID 39672241

  7. One Case of Sudden Isolated Adrenocorticotropic Hormone (ACTH) Deficiency Diagnosed Based on Repeated Hypoglycemic Attacks

    Sato T et al. · Cureus · 2025 Jun · PMID 40677481

  8. Benchmark for Setting ACTH Cell Dosage in Clinical Regenerative Medicine for Post-Operative Hypopituitarism

    Kondo T et al. · Diseases (Basel, Switzerland) · 2025 Apr 10 · PMID 40277822

Live feed from PubMed (NCBI) for “GHRP-2”, updated 2026-10-30. Listing a paper is not an endorsement of its findings.

Key references

  1. [1]Bowers, 1998 — Cell Mol Life Sci
  2. [2]PubMed — reviews on GHRP-2 and GH secretion
  3. [3]WADA — Prohibited List of Substances and Methods

FAQ

  • Both activate the ghrelin receptor, but GHRP-2 is generally more potent at releasing growth hormone and produces measurable increases in cortisol and prolactin, whereas ipamorelin is noted for its selectivity. Researchers choose between them depending on whether potency or receptor selectivity matters most for the study design.

  • Lyophilized GHRP-2 is normally kept sealed at −20 °C, protected from light and moisture. Once reconstituted for laboratory work, aliquots are held at 2–8 °C for short-term use or frozen, avoiding repeated freeze–thaw. Follow the lot-specific guidance on the certificate of analysis.

  • Every lot of GHRP-2 ships with a certificate of analysis reporting HPLC purity, mass-spectrometry identity against the expected molecular weight, appearance and lot number. Match the COA lot to the vial label and keep it with your experimental records.

FOR RESEARCH USE ONLY.Not for human or veterinary use. Not intended to diagnose, treat, cure, or prevent any disease.

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