Overview
Overview
GHRP-2 (Growth Hormone-Releasing Peptide-2) is a synthetic hexapeptide that stimulates potent, dose-dependent growth hormone release by activating ghrelin receptors[1]. Clinical studies predominantly employ once-daily subcutaneous administration to elicit robust pulsatile GH release while minimizing receptor desensitization[2][3]. This educational protocol presents a practical gradual titration approach with clear insulin-syringe measurements. Reconstitute: Add 3.0 mL bacteriostatic water → ~1.
- Category
- Growth Hormone
- Routes
- subcutaneous
Mechanism
GHRP-2
Mechanism of action
Mechanism of action
GHRP-2 is a synthetic growth hormone secretagogue that binds to and activates ghrelin (GH secretagogue) receptors [1] . This activation triggers potent, pulsatile release of growth hormone from the pituitary gland in a dose-dependent manner [4] . Clinical studies in GH-deficient children demonstrated meaningful GH increases even at low doses (0.3–3.0 mcg/kg), with escalating doses over several months showing sustained efficacy [2] . In healthy adults, doses of 100 mcg SC daily produce acute GH stimulation [3] , while routine protocols typically maintain 100–300 mcg/day to balance efficacy with receptor sensitivity. The peptide has been well tolerated in clinical trials with no significant adverse effects or toxicity reported at these dosage ranges [2] [7] .
Key research findings
- 01
Synthetic hexapeptide (also known as pralmorelin) that acts as an agonist at the growth hormone secretagogue receptor (GHS-R1a, the ghrelin receptor), stimulating GH release through a pathway distinct from GHRH analogs (pharmacology; foundational GHRP work by Bowers and colleagues).
- 02
In human research it produces a marked, dose-related rise in GH and has been used as a provocative GH-secretagogue stimulus in GH-axis testing (human study).
- 03
Approved in Japan (PMDA, 2004) as pralmorelin (brand 'GHRP Kaken,' Kaken Pharmaceutical) for use as a diagnostic stimulation agent for growth hormone deficiency; it is the only GHRP with regulatory approval anywhere and is not FDA-approved (regulatory fact).
- 04
Through ghrelin-pathway activity it may also modestly raise other pituitary hormones (e.g., prolactin, ACTH/cortisol) and stimulate appetite (animal and human pharmacology).
Primary source: Supported by foundational GH-secretagogue pharmacology (Bowers and colleagues) and human GH-stimulation studies; pralmorelin has a defined clinical-research role as a GH-axis test agent and holds a diagnostic approval in Japan. Long-term controlled outcome trials beyond GH-stimulation testing are limited.
Pharmacokinetic profile
Single-dose plasma curve over 24h. Shaded band = commonly-cited therapeutic window. Illustrative only.
Researched Effects
Protocol Reference
Protocol reference
Commonly cited research range: 100–300 mcg, daily.
Reference figures reported in the research literature — not a dosing recommendation. For interactive vial math and scheduling, see the Calculator and Schedule tabs.
Cited protocol & reconstitution guide
Source-backed reference fields by phase, including any volume fields authored in the cited guide.
Weeks 1–2
100 mcg
Weeks 3–4
150 mcg
Weeks 5–8
200 mcg
Weeks 9–12
200 mcg
Weeks 13–16
200 mcg
| Phase | Reference amount | Units / volume |
|---|---|---|
| Weeks 1–2 | 100 mcg | 6 units (0.06 mL) |
| Weeks 3–4 | 150 mcg | 9 units (0.09 mL) |
| Weeks 5–8 | 200 mcg | 12 units (0.12 mL) |
| Weeks 9–12 | 200 mcg | 12 units (0.12 mL) |
| Weeks 13–16 | 200 mcg | 12 units (0.12 mL) |
Storage & Handling
Storage requirements(typical for most peptides)
Can be stored for extended periods. Protect from moisture.
Store in refrigerator door. Never freeze after reconstitution.
Label vials with reconstitution date. Discard if cloudy.
Reconstitution steps
- 01🌡️Draw 3.0 mL bacteriostatic water with a sterile syringe.
- 02🧴Inject slowly down the vial wall; avoid foaming.
- 03💉Gently swirl or roll until completely dissolved (do not shake).
- 04💧Label and refrigerate at 2–8 °C (35.6–46.4 °F), protected from light.
- 05🔄Important: This guide is for educational purposes only and is not medical advice. For research use only. Not for human consumption.
Additional storage notes
Store at −20 °C (−4 °F) in dry, dark conditions; powder is stable at room temperature for short periods but freezer storage maximizes shelf life [8] .
Refrigerate at 2–8 °C (35.6–46.4 °F); use within 2–3 weeks for optimal integrity [9] . For longer storage, consider aliquoting and freezing at −20 °C (−4 °F) with carrier protein; avoid repeated freeze–thaw cycles.
Allow vials to reach room temperature before opening to reduce condensation uptake.
Always protect from light and heat.
Clinical Evidence
Clinical evidence
Studied as a potent GH secretagogue in endocrine research, including GH-stimulation testing contexts.
Supported by foundational GH-secretagogue pharmacology (Bowers and colleagues) and human GH-stimulation studies; pralmorelin has a defined clinical-research role as a GH-axis test agent and holds a diagnostic approval in Japan. Long-term controlled outcome trials beyond GH-stimulation testing are limited.
- 01Synthetic hexapeptide (also known as pralmorelin) that acts as an agonist at the growth hormone secretagogue receptor (GHS-R1a, the ghrelin receptor), stimulating GH release through a pathway distinct from GHRH analogs (pharmacology; foundational GHRP work by Bowers and colleagues).
- 02In human research it produces a marked, dose-related rise in GH and has been used as a provocative GH-secretagogue stimulus in GH-axis testing (human study).
- 03Approved in Japan (PMDA, 2004) as pralmorelin (brand 'GHRP Kaken,' Kaken Pharmaceutical) for use as a diagnostic stimulation agent for growth hormone deficiency; it is the only GHRP with regulatory approval anywhere and is not FDA-approved (regulatory fact).
- 04Through ghrelin-pathway activity it may also modestly raise other pituitary hormones (e.g., prolactin, ACTH/cortisol) and stimulate appetite (animal and human pharmacology).
Evidence maturity varies by compound; much peptide research is preclinical (in vitro or animal-model). Where human data are limited, findings should be read as research observations, not clinical conclusions.
References
Literature references
Published research articles and sources related to GHRP-2.
- 01Domest Anim Endocrinol — Effects of GHRP-2 on GH release and growth performance in swine (mechanism and receptor activation) View Source
- 02J Clin Endocrinol Metab — Effects of eight months treatment with graded doses of GHRP-2 in GH-deficient children View Source
- 03Eur J Endocrinol — Five-day treatment with daily subcutaneous GHRP-2: response attenuation and IGF-I effects in healthy young men View Source
- 04Endocrine — GH/IGF-1 response to acute and chronic GHRP-2, GHRH 1-44, and their combination in older adults View Source
- 05Am J Men’s Health — Growth hormone secretagogue treatment in hypogonadal men raises serum IGF-1 levels View Source
- 06Sex Med Rev (PMC) — The safety and efficacy of growth hormone secretagogues: comprehensive review View Source
- 07Genaxxon Bioscience — Product Information: Growth Hormone-Releasing Peptide-2 (GHRP-2), technical specifications View Source
- 08Genaxxon Bioscience — Storage and stability guidelines for research peptides (lyophilized storage recommendations) View Source
- 09Genaxxon Bioscience — Reconstituted peptide storage: refrigeration and stability considerations View Source
- 10Nurseslabs — Subcutaneous administration technique: comprehensive nursing guide View Source
- 11Medicine LibreTexts (BCcampus) — Intradermal and subcutaneous injections: clinical procedures for safer patient care View Source
- 12Chartwell Pennsylvania — Administering medication via subcutaneous injection: patient teaching guide View Source
- 13Medicine LibreTexts (BCcampus) — Site rotation and lipodystrophy prevention in subcutaneous injections View Source
- 14Pure Lab Peptides — GHRP-2 (5 mg) product page (quality documentation and batch COAs) View Source
Research Considerations
Research considerations
Research Use Only - not for human or veterinary therapeutic use. Has been studied in clinical research; on this platform it is handled strictly as a research material. Consult a licensed healthcare professional for any clinical decisions.
Factors noted in the research literature; not patient-specific medical advice.
Regulatory Status
Regulatory status
RUO
Comparisons
Comparisons
| Compound | Mechanism | Route | Status |
|---|---|---|---|
| GHRP-2this | A synthetic hexapeptide that activates the ghrelin/GHS receptor (GHS-R1a) to stimulate dose-dependent growth hormone release; it also mildly engages prolactin and cortisol pathways. | subcutaneous | Investigational / RUO |
| GHRP-6 | A synthetic hexapeptide GH secretagogue that binds the ghrelin receptor (GHS-R1a) to stimulate pulsatile GH release and appetite via central ghrelin signaling. | subcutaneous | Investigational / RUO |
| HGH 191AA | Recombinant human growth hormone (somatropin), a 191-amino-acid protein identical to endogenous GH, acting on GH receptors to drive IGF-1 production and influence growth, metabolism, and tissue repair. | subcutaneous | Investigational / RUO |
| IGF-1 LR3 | A modified analog of insulin-like growth factor-1 with reduced binding to IGF-binding proteins, giving a markedly extended half-life and prolonged activation of IGF-1 receptor anabolic signaling. | subcutaneous | Investigational / RUO |
| Ipamorelin | Binds to ghrelin receptors to stimulate pituitary gland to release growth hormone. Highly selective with minimal side effects. | subcutaneous | Investigational / RUO |
| Glutathione | An endogenous tripeptide (gamma-L-glutamyl-L-cysteinyl-glycine) functioning as a major intracellular antioxidant and redox buffer, supporting phase-II detoxification conjugation and neutralization of reactive oxygen species. | subcutaneous | Investigational / RUO |
| Gonadorelin | A synthetic form of gonadotropin-releasing hormone (GnRH) acting on pituitary GnRH receptors to stimulate luteinizing hormone (LH) and follicle-stimulating hormone (FSH) release, supporting the hypothalamic-pituitary-gonadal axis. | subcutaneous | Investigational / RUO |
Attributes shown for research comparison only; not a statement of efficacy or therapeutic equivalence.
FAQ
Frequently asked questions
Growth hormone-releasing peptide-2, a synthetic hexapeptide (also called pralmorelin) that mimics ghrelin at the GHS-R1a receptor to stimulate GH release. Presented here as a research material; not medical advice.
GHRH analogs act at the GHRH receptor, while GHRP-2 acts at the separate ghrelin (GHS-R1a) receptor. The two pathways are complementary, which is why they are often studied together in GH-axis research.
Both are hexapeptide ghrelin-receptor agonists characterized in the early GHRP literature; in research GHRP-2 is generally reported as a more potent GH stimulus, while GHRP-6 is noted for stronger appetite stimulation. Selectivity profiles differ.
It has an established role as a GH-stimulation test agent and is approved in Japan as a diagnostic (pralmorelin). It remains unapproved in the US and is handled here as research-use-only.
Research-reported ranges vary; this workspace does not provide dosing instructions or medical advice. See the protocol reference materials and qualified sources.
Stored lyophilized and frozen, protected from light; reconstituted with bacteriostatic water and refrigerated (2-8C), avoiding freeze-thaw cycles. Follow the supplier certificate of analysis.
Research-use notice
Research Use Only. This educational content and calculation support is intended for private research documentation. It does not provide medical advice, human-use directions, or claims of safety or effectiveness.