Quick summary
GHRP-2 (Pralmorelin) is a potent growth hormone releasing peptide approved in Japan as a diagnostic agent for GH deficiency. It stimulates GH release via the ghrelin receptor with moderate appetite and cortisol effects, sitting between Ipamorelin and GHRP-6 in side effect profile.
Overview
GHRP-2 (Pralmorelin) is a synthetic hexapeptide ghrelin receptor agonist and potent growth hormone secretagogue. Approved in Japan as a diagnostic agent for GH deficiency, it is the most selective of the first-generation GHRPs, producing strong GH release with less appetite stimulation than GHRP-6 and lower cortisol/prolactin elevation than other peptides in its class.
Mechanism of action
GHRP-2 acts as a selective agonist at the ghrelin receptor (GHSR-1a) in the pituitary and hypothalamus. Binding triggers calcium mobilization and protein kinase C activation, resulting in pulsatile GH release from somatotroph cells. Simultaneously, GHRP-2 suppresses somatostatin tone, which normally inhibits GH secretion, thereby amplifying net GH output. It also activates hypothalamic neuropeptide Y (NPY) neurons, contributing to mild appetite stimulation — though this effect is significantly less pronounced than with GHRP-6. At standard doses GHRP-2 produces modest cortisol and prolactin elevation, which some users manage by pairing it with a GHRH analog. Its short plasma half-life (~15 minutes) requires multiple daily injections to maintain elevated GH pulsatility.
Dosing protocols
| Purpose | Route | Dosage | Frequency | Notes |
|---|---|---|---|---|
| GH secretion and body composition | subcutaneous | 100–300 mcg | 2–3 times daily | Users commonly inject 100–300 mcg per dose on an empty stomach, 3 times daily (morning, pre-workout, and pre-sleep). Often paired with a GHRH analog (CJC-1295, Mod-GRF 1-29) for synergistic effect. |
| diagnostic GH stimulation test (clinical use) | intravenous | 100–100 mcg | single dose | Japanese PMDA-approved diagnostic protocol: 100 mcg IV bolus, GH measured at 30, 60, and 90 minutes. Peak GH >16 ng/mL (children) or >9 ng/mL (adults) rules out deficiency. |
Dosing information is for educational purposes only. Consult a qualified healthcare professional before using any peptide.
Research summary
Approved by Japan's PMDA in 2004 as a diagnostic agent for GH deficiency assessment; a single 100 mcg IV bolus is the established clinical test dose. Preclinical and Phase 2 studies demonstrate robust GH and IGF-1 elevation in healthy adults and GH-deficient patients. Limited published data on long-term anabolic or body composition outcomes. Community use is widespread for muscle building, recovery, and anti-aging, but evidence is largely from user-reported protocols rather than controlled clinical trials.[1][2][3][4][5][6]
Evidence grading
Each claimed benefit is graded by the strength of available evidence. Grades reflect study quality, not effect size.
Strong = multiple RCTs · Moderate = limited trials or observational · Preliminary = animal or in vitro only · Insufficient = anecdotal or no published data
Side effects
Side effects vary by individual. This is not an exhaustive list. Report unusual symptoms to a healthcare professional.
Common stacks
Peptides commonly paired with GHRP-2 for synergistic effects.
Legal status
GHRP-2 was placed on the FDA Category 2 bulk drug substance list in September 2023, banning compounding pharmacy preparation in the US. Industry analysis as of February 2026 suggests GHRP-2 is among the peptides expected to remain on Category 2 (due to cortisol and prolactin elevation concerns) rather than returning to compounding-eligible status. No formal FDA update published as of April 2026. Approved as a diagnostic agent in Japan.
Sourcing & access
Reclassification in progress
GHRP-2 is one of 14 peptides under FDA reclassification review. Access may be restored through licensed compounding pharmacies if reclassification is formalized. Check our regulatory timeline for the latest status.
Frequently asked questions
GHRP-2 (Pralmorelin) is a synthetic hexapeptide that stimulates growth hormone secretion via the ghrelin receptor (GHS-R1a). It is approved in Japan as a diagnostic agent for GH deficiency testing and is widely used in the research community for body composition optimization.
GHRP-2 produces slightly less appetite stimulation than GHRP-6 while maintaining potent GH release. Both elevate cortisol and prolactin transiently. GHRP-2 is considered more selective, sitting between the clean profile of Ipamorelin and the strong appetite effects of GHRP-6.
GHRP-2 was placed on the FDA Category 2 bulk drug substance list in September 2023, banning compounding pharmacy preparation in the US. As of 2026, it is expected to remain on Category 2 due to cortisol and prolactin elevation concerns.
Research protocols commonly use 100 to 300 mcg per dose injected subcutaneously on an empty stomach, 2 to 3 times daily. It is often paired with a GHRH analog like CJC-1295 or Mod GRF 1-29 for synergistic GH release.
Side effects include mild increased appetite, transient cortisol and prolactin elevation, injection site redness, water retention, headache, and flushing. These effects are generally dose-dependent and resolve within hours as the short 15-minute plasma half-life clears. The cortisol and prolactin profile is the main reason GHRP-2 is expected to remain on FDA Category 2.
Research references
- Growth hormone-releasing peptides: clinical and basic aspectsPubMed
- Pharmacokinetics and pharmacodynamics of growth hormone-releasing peptide-2: a phase I study in childrenPubMed
- Growth hormone releasing peptide-2 (GHRP-2), like ghrelin, increases food intake in healthy menPubMed
- Growth hormone-releasing peptide-2 stimulates GH secretion in GH-deficient patients with mutated GH-releasing hormone receptorPubMed
- Clinical Usefulness of the Growth Hormone-Releasing Peptide-2 Test for Hypothalamic-Pituitary DisorderPubMed
- Two ghrelin receptor agonists for adults with malnutrition: a systematic review and meta-analysisPubMed