GHRP-2

GHRP-2 (Growth Hormone Releasing Peptide-2), also known as Pralmorelin, is a synthetic hexapeptide growth hormone secretagogue that acts on the ghrelin receptor (GHS-R1a) to stimulate growth hormone release from the pituitary gland. Developed as an improvement over GHRP-6, it is generally considered to produce stronger GH release per microgram while having somewhat less pronounced appetite-stimulating effects, making it a more refined tool for GH axis research and clinical applications.

GHRP-2 is notable for being one of the few GH secretagogue peptides to achieve regulatory approval anywhere in the world. In Japan, it is approved under the name Pralmorelin (marketed as GHRP Kaken 100) for use as a diagnostic agent to evaluate growth hormone secretion in suspected GH deficiency. This approval lends it a degree of clinical validation that many other research peptides lack.

Comparative studies have characterized GHRP-2 as producing the most potent GH release among the GHRP family of peptides. Like GHRP-6, it can elevate cortisol and prolactin, but typically to a lesser degree at equipotent GH-releasing doses. The appetite-stimulating effect is present but generally milder than GHRP-6, making it a middle-ground option between the strong hunger of GHRP-6 and the minimal appetite effect of Ipamorelin.

Research applications for GHRP-2 extend beyond simple GH stimulation. Studies have explored its effects on sleep architecture, showing it can enhance slow-wave sleep — the most restorative sleep phase. Additionally, preclinical research has investigated its potential cytoprotective and anti-inflammatory properties. GHRP-2 has been used extensively in endocrinology research to study the interplay between ghrelin signaling and the growth hormone axis.