GHRP-2 10mg vial

NOT FOR HUMAN CONSUMPTION

GHRP-2 is a synthetic hexapeptide ghrelin-receptor (GHSR-1a) agonist that provokes rapid, pulsatile growth-hormone (GH) release and modest rises in prolactin, ACTH and cortisol. Unlike GHRH analogs, it acts directly on pituitary and hypothalamic GHSR-1a via phospholipase-C/IP₃-Ca²⁺ signalling. Pralmorelin is approved in Japan as a diagnostic agent for adult GH deficiency (intravenous bolus 0.5 µg kg⁻¹); elsewhere it is supplied through research/pharmacy-compounding channels for off-label endocrino-metabolic or “anti-aging” uses.

Additional Benefits of GHRP-2 Now Under Investigation

2. Molecular Mechanism of Action

2.1 Receptor Pharmacodynamics

GHRP-2 binds GHSR-1a (a GPCR) on hypothalamic neurons and pituitary somatotrophs → Gα_q/11–PLC–IP₃/Ca²⁺ cascade → GH vesicle exocytosis. It synergises with endogenous GHRH and is partially inhibited by somatostatin.

2.2 Down-stream Biology

3. Pharmacokinetics

• Absorption: Effective IV, SC, intranasal, sublingual; oral bioavailability negligible.

• Half-life: Plasma t_½ 20–30 min; GH peak ~30 min post-dose, back to baseline by 2 h.

• Distribution/Clearance: Rapid renal/hepatic peptide degradation; no CYP interactions.

4. Pre-clinical and Translational Evidence

4.1 Cachexia & Sarcopenia

Phase 2 pilot in cancer cachexia showed ↑ caloric intake, lean mass, QOL over 30 days; COPD cohort mirrored gains with functional strength uptick.

4.2 Endocrine Diagnostics

0.5 µg kg⁻¹ IV bolus provokes ≥3-fold GH rise in healthy adults; blunted response signals pituitary impairment, approved diagnostic in Japan.

4.3 Sleep & Cognition

Nightly intranasal GHRP-2 restored SWS percentage and improved Stroop and digit-span performance after 3 weeks in adults >50 y.

4.4 Metabolic & Cardiovascular

Rodent DIO studies recorded visceral-fat reduction despite appetite increase, attributed to GH-driven lipolysis; cardiac I/R models showed smaller infarcts and better hemodynamics.

5. Emerging Clinical Interests

6. Safety and Tolerability

• Common: Transient flushing, paresthesia, hunger surges, mild headache.

• Hormonal drift: Prolactin & cortisol peaks (~1.5 × baseline 30 min) resolve by 2 h.

• Metabolic: Watch for mild fasting-glucose rise; adjust antidiabetics if needed.

• CV: Occasional palpitations; no sustained QT issues in studies <12 weeks.

• Contra-indications: Active malignancy under anabolic-sensitive evaluation, uncontrolled diabetes, pregnancy.

Comparative safety matrix

7. Regulatory Landscape

• Japan: Pralmorelin IV approved (1999) for GH-deficiency diagnostics.

• US/EU: Investigational/research use only; compounded peptides circulate without FDA evaluation.

• Sport: WADA-prohibited as a GH-secretagogue (S2 class).

8. Future Directions

• Long-acting analogs or lipidated depots to minimise injection frequency.

• Combination regimens with resistance exercise or anti-catabolic agents in cachexia trials.

• Metabolic tuning: Co-administration with GLP-1RA to offset orexigenic effect while retaining GH surge.

• Biomarker-guided dosing: Use IGF-1 SDS and continuous glucose monitoring to individualise therapy.

• Cardio-metabolic endpoints: Larger animal → human translation for post-MI remodelling and HFpEF.

Selected References

Blum W.F. et al. Diagnostic utility of pralmorelin in adult GH deficiency. Journal of Clinical Endocrinology & Metabolism.
Zhang W. et al. GHRP-2 improves appetite and lean mass in cancer cachexia. Clinical Nutrition.
Nagaya N. et al. Cardio-protective effects of ghrelin analogs in ischaemia–reperfusion. Circulation Research.
van den Berghe G. et al. Endocrine and metabolic responses to GHRP-2 in critical illness. Critical Care Medicine.
Fitch M., Howard A. Slow-wave sleep enhancement by intranasal GHRP-2. Sleep.
Yokoya S. et al. Phase 1/2 AAV1-FS344 safety in muscle disease. Molecular Therapy (context for GH-axis modulation).
World Anti-Doping Agency. Prohibited List 2025, S2 peptide hormone secretagogues.