See GHRP-2 dosage distribution, reconstitution patterns, and vial size preferences from anonymized WPA peptide calculator sessions.
Often paired with a GHRH peptide in multi-injection protocols, GHRP-2 demands precise mcg-level dosing across multiple daily injections. This data reveals the dose amounts, vial sizes, and bacteriostatic water volumes researchers most commonly use when reconstituting this ghrelin receptor agonist.
GHRP-2 (Growth Hormone Releasing Peptide-2) is a synthetic hexapeptide GHS-R1a (ghrelin receptor) agonist developed by the Cyril Bowers laboratory at Tulane University through a series of papers in the late 1980s and 1990s that mapped the structure-activity relationships of opioid-derived growth hormone secretagogues. The lineage runs from Bowers' earlier GHRP-6 (the original member of the GHRP family) to GHRP-2 as the more potent and more selective second-generation variant, and from there to the non-peptide secretagogues that ultimately culminated in MK-677 (ibutamoren). , Nature) identified as the native receptor for the endogenous peptide ghrelin — to potently amplify pulsatile GH release from pituitary somatotrophs.
GHRP-2 (pralmorelin) is a synthetic hexapeptide growth-hormone secretagogue, most often sourced for GH-axis and appetite research. It is approved in Japan as a single-dose diagnostic agent but has no FDA approval in the United States. It ships as a lyophilized powder you reconstitute with bacteriostatic water before use.
GHRP-2 is a selective agonist of the ghrelin / growth-hormone-secretagogue receptor (GHS-R1a) expressed on pituitary somatotropes and hypothalamic neurons. Receptor activation stimulates GH release through a pathway independent of (but synergistic with) GHRH-receptor signaling, and also stimulates appetite via parallel ghrelin-mediated central pathways. Unlike ipamorelin, GHRP-2 also weakly stimulates prolactin and ACTH/cortisol secretion.
A single-dose GHRP-2 stimulation test was validated in Japanese pediatric and adult cohorts (Chihara et al.) as a diagnostic alternative to the insulin-tolerance test for severe GH deficiency, supporting its 2006 Japanese regulatory approval. Chronic dosing trials in cachexia (CP-424391-related work) and adult GH deficiency have been published but have not advanced to Phase 3.
GHRP-2 has a reported half-life of ~30 min, and the dose intervals researchers model most often fall around once daily (often before bed). Very short-acting — it triggers a GH pulse and then clears within the hour, with no buildup. Many users dose two or three times a day to repeat the pulse. It is catalogued under Muscle Peptides on WPA.
85 GHRP-2 reconstitution calculations have been logged by the WPA community. The most common dose entered is 150mcg (25 calculations). The median dose across all sessions is 160mcg. The most common bacteriostatic water volume is 3mL. The most popular vial size is 10mg (43 sessions). The most common dosing frequency is daily (7x/week) (3 logged protocols), followed by 5x/week (3).
These figures come from anonymized WPA peptide calculator sessions.
All figures shown are aggregated from anonymized calculator inputs and are provided strictly for independent laboratory research and educational purposes. They are community usage statistics — not dosing recommendations, and not medical advice.