Is GHRP-2 an approved drug?

No. GHRP-2 (pralmorelin) is supplied for research use only and is not an approved drug in Canada or the United States. Its only regulatory approval is in Japan, where it is used as a single-injection diagnostic agent for growth hormone deficiency, not as a therapeutic. It is not intended for human or veterinary use.

How does GHRP-2 work?

Researchers reported that GHRP-2 is an agonist at the growth hormone secretagogue receptor (GHS-R1a) — the same receptor targeted by the natural peptide ghrelin — and that it stimulates pituitary growth hormone release in published pharmacology studies.

What did human studies report?

In a small study of 7 healthy men, subcutaneous GHRP-2 infusion raised serum growth hormone and increased food intake by about 36% versus saline. In 10 growth-hormone-deficient children, long-term oral GHRP-2 was associated with a transient increase in appetite. These are reported research observations, not directions for use.

What is its molecular formula and weight?

Per PubChem (CID 6918245), GHRP-2 has the molecular formula C45H55N9O6 and a molecular weight of 818.0 g/mol, with CAS number 158861-67-7.

GHRP-2 Dosage, Half-Life & Research

Q: What is the evidence grade?

Grade B: limited human data (a single-country diagnostic approval plus small short-term studies) supported by strong, reproducible animal pharmacology. No large long-term randomized controlled trials have established therapeutic efficacy or safety.

GHRP-2 (pralmorelin) is a synthetic hexapeptide growth hormone secretagogue developed from the GHRP-6 scaffold by Cyril Bowers and colleagues at Tulane University.⁵ It is the only growth hormone-releasing peptide to have reached regulatory approval anywhere: in Japan it is marketed by Kaken Pharmaceutical (GHRP Kaken 100) strictly as a single-injection diagnostic agent for growth hormone deficiency, and it was never approved as a therapeutic in any jurisdiction.² It is not an approved drug in Canada or the United States. This material is offered for laboratory research use only; the information below summarizes what published studies have reported and is not directions for use in humans.

Structure

Sequence & identity

H-D-Ala-D-2-Nal-Ala-Trp-D-Phe-Lys-NH₂ · C₄₅H₅₅N₉O₆ · 818.0 g/mol

Hexapeptide C-terminal amide containing the non-proteinogenic residue D-2-naphthylalanine. Identity per PubChem CID 6918245 (InChIKey HRNLPPBUBKMZMT-RDRUQFPZSA-N).³

What the research shows

Mechanisms studied

Researchers reported that GHRP-2 acts as an agonist at the growth hormone secretagogue receptor (GHS-R1a), the same receptor later identified as the target of the endogenous peptide ghrelin.⁴ In pharmacology studies of KP-102 (GHRP-2), investigators observed potent, dose-dependent stimulation of pituitary growth hormone release, acting at both pituitary and hypothalamic sites and synergizing with GHRH.⁵ Because the receptor is shared with ghrelin, studies also reported activation of other ghrelin-linked pathways — most notably stimulation of appetite/food intake.⁶ In conscious swine, researchers reported that GHRP-2 (like GHRP-6) raised plasma ACTH and cortisol, in contrast to the more GH-selective analog ipamorelin.¹

Reported in studies

Dosing in the research literature

The figures below summarise regimens as reported in published research — they are not recommendations or directions for use.

Source / model	Regimen reported	Notes
Laferrère et al., J Clin Endocrinol Metab 2005 (PMID 15699539)	1 µg/kg/h continuous subcutaneous infusion over 270 minutes in 7 lean healthy men	As reported in this study, not a usage direction. Serum GH AUC rose markedly (5550 ± 1090 vs 412 ± 161 µg/L/240 min, p=0.003) and food intake increased 35.9 ± 10.9% vs saline.⁶
Mericq et al., J Pediatr Endocrinol Metab 2003 (PMID 14513874)	900 µg/kg orally twice daily for 12 months in 10 GH-deficient prepubertal children (mean age 10.4 yr)	Reported in a clinical research setting only. 7/10 reported increased appetite in the first 6 months; BMI SDS trended upward without reaching significance.⁷
Japanese diagnostic labeling (pralmorelin, Kaken)	Single 100 µg intravenous bolus as a GH-stimulation diagnostic test	Approved use in Japan is diagnostic and single-dose; not a therapeutic regimen and not approved in Canada/US.²

Research use only. Peptigo products are sold to qualified researchers for laboratory use. This information summarises published research for reference and is not medical advice, a dosing recommendation, or directions for human or animal use.

Reported in studies

Effects observed in research

In healthy men, researchers observed that subcutaneous GHRP-2 infusion produced a large, significant rise in serum growth hormone and increased ad libitum food intake by roughly 36% versus saline, with greater pre-meal appetite ratings.⁶ In growth-hormone-deficient children, investigators reported that long-term oral GHRP-2 was associated with a transient increase in appetite in most participants over the first six months.⁷ Animal pharmacology studies characterized GHRP-2 as a highly potent GH releaser; in swine, ED50 was reported at ~0.6 nmol/kg with a maximal effect of 56 ± 6 ng GH/mL plasma.¹ Studies also reported that, unlike the GH-selective analog ipamorelin, GHRP-2 elevated ACTH and cortisol, and other GHS-R agonists in this class can produce modest, transient increases in prolactin.¹ Long-term human safety and efficacy for any therapeutic indication have not been established.

Honest assessment

Strength of evidence

Grade B

Grade B. Human data exist but are limited: a single approved indication in one country (diagnostic, single-dose GH stimulation),² a small acute infusion study in 7 healthy men,⁶ and a 12-month open-label study in 10 GH-deficient children focused on appetite/BMI rather than controlled growth outcomes.⁷ These are supported by strong, reproducible animal pharmacology.¹⁵ There are no large, long-term randomized controlled trials establishing therapeutic efficacy or safety, and Phase II development for GH deficiency and short stature was discontinued.² Reported half-life figures vary widely across non-primary sources and should be treated as approximate; a precise, peer-reviewed human elimination half-life is not well established in the public literature. Effects described here are what researchers reported in the cited models, not anticipated outcomes in any individual.

Handling

Reconstitution & storage

Reconstitute with bacteriostatic water for laboratory handling. Store lyophilised material frozen and reconstituted material refrigerated. Use Peptigo’s reconstitution calculator and storage cheat sheet for working figures.

References

Raun K, Hansen BS, Johansen NL, et al. Ipamorelin, the first selective growth hormone secretagogue. Eur J Endocrinol. 1998;139(5):552-561. (comparative GHRP-2 swine data, ACTH/cortisol) PMID: 9849822
Pralmorelin (GHRP-2, KP-102, GPA-748): approved in Japan (Kaken Pharmaceutical, GHRP Kaken 100) as a diagnostic agent for growth hormone deficiency; not approved as a therapeutic; not approved in Canada or the US. AdisInsight/Drugs in R&D drug profile, PMID: 15230633; Wikipedia: Pralmorelin (https://en.wikipedia.org/wiki/Pralmorelin)
National Center for Biotechnology Information. PubChem Compound Summary for CID 6918245, Pralmorelin (GHRP-2). MolecularFormula C45H55N9O6; MolecularWeight 818.0 g/mol; InChIKey HRNLPPBUBKMZMT-RDRUQFPZSA-N; CAS 158861-67-7. https://pubchem.ncbi.nlm.nih.gov/compound/6918245
Bowers CY. Growth hormone-releasing peptide (GHRP). Cell Mol Life Sci. 1998;54(12):1316-1329 — GHRP-2 as GHS-R agonist; GHS-R later identified as the ghrelin receptor (Howard AD, et al. Science. 1996;273:974-977).
Pharmacological characteristics of KP-102 (GHRP-2), a potent growth hormone-releasing peptide. PMID: 15646370 (Arzneimittelforschung, 2004).
Laferrère B, Abraham C, Russell CD, Bowers CY. Growth hormone releasing peptide-2 (GHRP-2), like ghrelin, increases food intake in healthy men. J Clin Endocrinol Metab. 2005;90(2):611-614. PMID: 15699539
Mericq V, Cassorla F, Bowers CY, Avila A, Gonen B, Merriam GR. Changes in appetite and body weight in response to long-term oral administration of the ghrelin agonist GHRP-2 in growth hormone deficient children. J Pediatr Endocrinol Metab. 2003;16(7):981-985. PMID: 14513874

Written by the Peptigo Research Team · scientifically reviewed by Peter, Peptigo Research Team · Last reviewed June 2026. We cite primary literature and flag where evidence is limited. Our sourcing & RUO policy →