GHRP-2

GHRP-2 (pralmorelin) is a synthetic hexapeptide that potently stimulates growth hormone release by mimicking ghrelin at the GHS-R1a receptor on pituitary somatotrophs. It is the most potent GHRP in terms of peak GH release — producing larger GH pulses than ipamorelin, GHRP-6, or hexarelin — but with a less clean side effect profile. Unlike ipamorelin, GHRP-2 significantly increases cortisol (~20-40% transient elevation) and prolactin (~50-100% transient elevation), which limits its use in protocols where hormonal cleanliness matters. It also stimulates appetite via ghrelin pathway activation, though less than GHRP-6. GHRP-2 is approved in Japan as a diagnostic agent for GH deficiency (pralmorelin/GHRP Kaken). The synergy with GHRH analogs (CJC-1295, mod-GRF 1-29) is well-documented: GHRP-2 + GHRH produces 5-10x the GH release of either alone. Preferred by users who want maximum GH output and tolerate the cortisol/prolactin trade-off.