GHRP-2

Typical use cases

Dosing guidelines

Titration

Community protocols commonly describe beginning at a lower per-dose amount to assess tolerance (appetite surge, water retention, head-rush) before adjusting frequency or pairing with a GHRH analog. This is educational only and not a recommendation.

Reconstitution

Lyophilized powder is typically reconstituted with bacteriostatic 0.9% sodium chloride or sterile/bacteriostatic water; a common research approach is ~1-2 mL per 5 mg vial, swirled gently (not shaken) and added down the vial wall.

Injection sites

Subcutaneous injection, typically into the abdominal fat (rotating sites) or other subcutaneous areas such as the thigh; intranasal and IV routes have been used in research/diagnostic settings.

Storage & handling

Lyophilized powder stored refrigerated (2-8 C) or frozen for long-term; once reconstituted, kept refrigerated and protected from light, generally used within a few weeks. Avoid repeated freeze-thaw of the solution.

Side effects

• Increased appetite / hunger Mild · Common
• Water retention and mild edema Mild · Common
• Transient increases in cortisol and prolactin Mild · Uncommon
• Injection-site reaction (redness, itching) Mild · Uncommon
• Head-rush, flushing, or tingling shortly after dosing Mild · Uncommon
• Reduced insulin sensitivity / elevated blood glucose with sustained use Moderate · Uncommon

Research summary

GHRP-2 (pralmorelin, KP-102) is a synthetic C-terminally amidated hexapeptide that acts as an agonist at the growth-hormone secretagogue receptor (GHS-R1a), the same receptor bound by the endogenous gut hormone ghrelin. Human pharmacology studies (largely small acute-infusion and diagnostic-testing trials in healthy adults, GH-deficient children, and the elderly) consistently show that GHRP-2 produces a sharp, dose-dependent rise in serum GH by both amplifying GHRH signaling and reducing somatostatin tone at the hypothalamus while directly stimulating pituitary somatotrophs. A controlled study in healthy men also demonstrated that GHRP-2 infusion increased food intake by roughly a third, mirroring ghrelin's orexigenic action. A phase I pharmacokinetic study in children reported a relatively short plasma half-life (terminal t1/2 ~0.55 h) alongside a robust, predictable GH peak. Because of its reliable GH response, GHRP-2 has been investigated as a diagnostic agent for GH deficiency and was developed under the name pralmorelin in Japan for that indication. The evidence base is dominated by short-term mechanistic and provocative-test studies; long-term, large-scale efficacy and safety data for sustained therapeutic or performance use in humans are lacking, and the compound is not FDA-approved for general therapeutic use. Reviews of growth-hormone secretagogues note generally good acute tolerability but flag incompletely characterized chronic effects on glucose handling/insulin sensitivity, cortisol/prolactin, and appetite-driven weight gain.

Key references

• https://pmc.ncbi.nlm.nih.gov/articles/PMC2824650/
• https://pubmed.ncbi.nlm.nih.gov/9543135/
• https://pmc.ncbi.nlm.nih.gov/articles/PMC5632578/
• https://pubchem.ncbi.nlm.nih.gov/compound/5493556
• https://drugs.ncats.io/drug/pralmorelin

Related compounds