GHRP-2

Overview

GHRP-2 (pralmorelin) is a synthetic hexapeptide ghrelin receptor agonist that stimulates pituitary growth hormone release. It is approved in Japan (Kaken Pharmaceutical, 2004) as a single-dose diagnostic agent for GH deficiency, but is NOT FDA-approved in the US and is research-only. Unlike ipamorelin, GHRP-2 is non-selective and modestly raises ACTH, cortisol, and prolactin.

Mechanism of Action

GHRP-2 binds the ghrelin/GHS-R1a receptor on pituitary somatotrophs and in the hypothalamus, triggering Gq-coupled calcium signaling and pulsatile GH release while also suppressing somatostatin tone. At therapeutic and supratherapeutic doses it produces measurable rises in ACTH, cortisol, and prolactin (less than GHRP-6 or hexarelin, but more than ipamorelin) and stimulates appetite through ghrelin-pathway activation.

Research Summary

GHRP-2 is approved in Japan (Kaken Pharmaceutical, 2004) as pralmorelin for single-dose diagnostic GH-stimulation testing; Chihara et al. (2007, PMID 17609397) validated a 100 mcg IV dose with a peak-GH <15 mcg/L cut-off against the insulin tolerance test. Arvat et al. (1997, PMID 9285939) showed GHRP-2 raises GH, prolactin, ACTH, and cortisol in healthy men, with hormonal effects similar to hexarelin. Laferrère et al. (2005, PMID 15699539) demonstrated that IV GHRP-2 significantly increases food intake in healthy men, consistent with its ghrelin-like activity. Pralmorelin review: Drugs R D 2004 (PMID 15230633). GHRP-2 is more potent than ipamorelin for raw GH output but is non-selective; grey-market anti-aging, muscle-gain, and performance use is not clinically validated in the US.

Vendors selling GHRP-2

Scored vendors carrying GHRP-2, ranked by trust grade. Grades are computed from indexed Certificates of Analysis. Full $/mg pricing is on the comparison page.

Prescribers who offer GHRP-2

13 prescribers in our directory work with GHRP-2, each confirmed from their own website. Peptides like GHRP-2 require a prescription from a licensed provider.

Reported Side Effects

• Increased appetite (ghrelin effect)
• Water retention
• Facial flushing
• Transient ACTH, cortisol, and prolactin elevation
• Tingling/numbness in extremities
• Injection-site reactions
• Insulin resistance / hyperglycemia risk with sustained GH elevation

Compare GHRP-2 with Others

Research References

• Pralmorelin: GHRP 2, GPA 748, growth hormone-releasing peptide 2, KP 102 (2004)
• A simple diagnostic test using GH-releasing peptide-2 in adult GH deficiency (Chihara et al.) (2007)
• Effects of GHRP-2 and hexarelin, two synthetic GH-releasing peptides, on GH, prolactin, ACTH and cortisol levels in man (Arvat et al.) (1997)
• Growth Hormone Releasing Peptide-2 (GHRP-2), like ghrelin, increases food intake in healthy men (Laferrère et al.) (2005)

Frequently asked questions

Has GHRP-2 been independently lab-tested?

Disclosed Labs has collected 13 Certificates of Analysis (COA) for GHRP-2 from 6 independent testing labs. 8 vendors have submitted material for testing. Products average 99.3% tested purity across the corpus. Full testing data is available at https://www.disclosedlabs.com/peptides/ghrp-2/testing.

What is the average purity of GHRP-2 on the market?

Based on 13 COAs analyzed by Disclosed Labs, GHRP-2 products average 99.3% (±0.5%) tested purity. Individual vendor results vary; see per-vendor COA data at https://www.disclosedlabs.com/peptides/ghrp-2/coas.

Which labs have tested GHRP-2?

Independent labs that have tested GHRP-2 include: ILS Labs (Grade A). Full lab credibility grades and profiles are at https://www.disclosedlabs.com/labs.

Where can researchers source GHRP-2?

6 vendors with Disclosed Labs trust grades currently list GHRP-2, including Peptidology, Real Peptides, Verified Peptides. Compare live prices and lab-verified COAs at https://www.disclosedlabs.com/prices/ghrp-2.

Which prescribers offer GHRP-2 with a prescription?

13 prescribers in the Disclosed Labs directory work with GHRP-2, each confirmed from their own website. GHRP-2 requires a prescription from a licensed provider. Browse them at https://www.disclosedlabs.com/prescribers?peptide=GHRP-2.

How does GHRP-2 work?

GHRP-2 binds the ghrelin/GHS-R1a receptor on pituitary somatotrophs and in the hypothalamus, triggering Gq-coupled calcium signaling and pulsatile GH release while also suppressing somatostatin tone. At therapeutic and supratherapeutic doses it produces measurable rises in ACTH, cortisol, and prolactin (less than GHRP-6 or hexarelin, but more than ipamorelin) and stimulates appetite through ghrelin-pathway activation.

What does the research say about GHRP-2?

GHRP-2 is approved in Japan (Kaken Pharmaceutical, 2004) as pralmorelin for single-dose diagnostic GH-stimulation testing; Chihara et al. (2007, PMID 17609397) validated a 100 mcg IV dose with a peak-GH <15 mcg/L cut-off against the insulin tolerance test. Arvat et al. (1997, PMID 9285939) showed GHRP-2 raises GH, prolactin, ACTH, and cortisol in healthy men, with hormonal effects similar to hexarelin. Laferrère et al. (2005, PMID 15699539) demonstrated that IV GHRP-2 significantly increases food intake in healthy men, consistent with its ghrelin-like activity. Pralmorelin review: Drugs R D 2004 (PMID 15230633). GHRP-2 is more potent than ipamorelin for raw GH output but is non-selective; grey-market anti-aging, muscle-gain, and performance use is not clinically validated in the US.