GHRP-2 — Research, Dosing & Price Guide

GHRP-2 (Growth Hormone Releasing Peptide-2, pralmorelin) is a synthetic hexapeptide that potently stimulates growth hormone release by activating the ghrelin receptor (GHS-R1a) in the anterior pituitary. It is one of the most potent GHRPs available, producing robust GH pulses comparable to GHRH stimulation tests. GHRP-2 also stimulates appetite, modulates cortisol and prolactin, and has demonstrated cytoprotective properties.

GHRP-2 binds to the growth hormone secretagogue receptor (GHS-R1a) on somatotroph cells in the anterior pituitary gland. This triggers intracellular calcium mobilization through the phospholipase C/IP3 pathway, resulting in GH vesicle exocytosis. Unlike GHRH, which amplifies existing GH pulses, GHRP-2 can initiate new GH release independently by acting through a completely separate receptor pathway. GHRP-2 also antagonizes somatostatin's inhibitory tone on GH release, meaning it works even when somatostatin levels are high (as occurs during aging). At the hypothalamic level, GHRP-2 stimulates GHRH-producing neurons and suppresses somatostatin-producing neurons, creating a dual amplification effect. GHRP-2 notably increases cortisol and prolactin more than Ipamorelin or GHRP-6, which is why it is sometimes considered less 'clean' despite its potent GH release.

• Bowers et al. demonstrated GHRP-2 produces the most potent GH release among the GHRP family when combined with GHRH (Journal of Clinical Endocrinology & Metabolism, 1990s series)
• Clinical studies showed GHRP-2 at 1 mcg/kg IV produces peak GH levels of 50–90 ng/mL in healthy adults (Hormone Research, 1997)
• GHRP-2 is used clinically in Japan (pralmorelin, brand name GHRP Kaken) as a diagnostic agent for GH deficiency
• Studies in GH-deficient children showed GHRP-2 increased growth velocity and IGF-1 levels comparably to exogenous GH treatment
• Research demonstrated cytoprotective effects of GHRP-2 on hepatocytes and cardiomyocytes via GHS-R1a-independent mechanisms
• A study in the Journal of Endocrinology (2003) showed sustained GH-releasing efficacy of GHRP-2 even after 30 days of continuous administration

• Standard dose: 100–300 mcg subcutaneous injection, 2–3 times daily
• Optimal timing: upon waking (fasted), post-workout, and before bed for maximum GH pulse frequency
• Clinical diagnostic dose: 1 mcg/kg IV (used in GH stimulation testing)
• Saturation dose: approximately 100 mcg (1 mcg/kg for a 100 kg individual) — higher doses don't proportionally increase GH
• Cycle length: 8–12 weeks on, 4 weeks off to prevent desensitization
• Best results on an empty stomach — food (especially fats and carbohydrates) blunts GH response by 50–75%
• Often combined with a GHRH analog (CJC-1295) for synergistic GH amplification (3–5x greater response than either alone)
• Avoid within 2 hours of eating; wait at least 30 minutes after injection before consuming food

Known Side Effects

• Increased appetite (ghrelin-mimetic effect) — can be significant, especially at higher doses
• Transient cortisol elevation (15–30% above baseline) — more pronounced than with Ipamorelin
• Mild prolactin increase — generally clinically insignificant but may be relevant for prolactin-sensitive individuals
• Water retention and mild bloating during the first 1–2 weeks
• Tingling or numbness in extremities (paresthesia) shortly after injection
• Occasional dizziness or lightheadedness, particularly when injecting in a fasted state
• Injection site reactions: redness, itching

Safety Profile

GHRP-2 has a well-established safety profile from clinical research and its approved diagnostic use in Japan. In clinical studies at standard doses, serious adverse events are rare. The main concerns are its effects on cortisol and prolactin — while modest, chronic elevation of either hormone can have clinical consequences. Cortisol elevation is transient (returns to baseline within 60–90 minutes) and does not appear to produce sustained hypercortisolism. Prolactin elevation is similarly transient but should be monitored in those with prolactinoma history. Individuals with diabetes should monitor blood glucose as GH can antagonize insulin action. Not recommended during active cancer (GH/IGF-1 may promote tumor growth). Contraindicated in pregnancy and breastfeeding. Safe for extended use with appropriate cycling.

Week 1: Noticeable increase in appetite within hours of first injection. Improved sleep quality, especially when dosing before bed. Mild water retention and occasional tingling after injection. Week 2–4: Improved recovery from exercise, better sleep depth, skin quality begins to improve. Fat loss may begin, though appetite increase can offset this if diet is not controlled. Weeks 5–8: Measurable improvements in body composition (reduced fat, increased lean mass) especially when combined with resistance training. Hair and nail growth often accelerates. IGF-1 levels typically elevate 30–60% above baseline. Weeks 9–12: Peak benefits for body composition, recovery, and anti-aging markers. After cycling off, benefits gradually diminish over 2–4 weeks as GH patterns return to baseline.

Prices sourced from peptides.gg marketplace. Prices may vary.