Hormonal
GHRP-2
Also known as: Growth Hormone Releasing Peptide-2, Pralmorelin, KP-102, GPA-748, WAY-GPA-748
A synthetic growth-hormone secretagogue and ghrelin-receptor agonist that triggers pulsatile GH release; backed by real human pharmacology data and a Japanese diagnostic...
Last updated July 11, 2026
Overview
GHRP-2 (pralmorelin; development codes KP-102 / GPA-748) is a small synthetic peptide growth-hormone secretagogue. It belongs to the GHRP family first described by Cyril Bowers and acts as an agonist at the growth-hormone secretagogue receptor (GHS-R1a), the same receptor targeted by the natural hormone ghrelin. Rather than supplying growth hormone directly, GHRP-2 prompts the pituitary to release its own GH in a pulsatile pattern.
Compared with most compounds in the research-peptide market, GHRP-2 has an unusually concrete human evidence base. Phase I pharmacokinetic and pharmacodynamic work has been published in children, healthy-adult studies have characterized its GH and food-intake effects, and the synergy between GHRPs and GH-releasing hormone (GHRH) is well documented in humans. In Japan, pralmorelin is approved (as a diagnostic agent, marketed by Kaken Pharmaceutical) for provocative testing of growth-hormone deficiency, making it one of the few GH secretagogues to reach any regulatory approval.
It is important to be clear about what that approval is and is not. GHRP-2 is approved in Japan only as a single-dose diagnostic test, not as a treatment, and it is not approved as a drug for GH deficiency, anti-aging, or body composition in the United States, the EU, or most jurisdictions. It is prohibited in sport by WADA. Material sold online is labeled for research use only.
This entry summarizes the published science and community-reported practice for reference only. It is not medical advice and does not endorse human use.
How it works
GHRP-2 binds GHS-R1a, a Gq-coupled G-protein-coupled receptor expressed in the pituitary and hypothalamus. Receptor activation raises intracellular calcium through the phospholipase-C / protein-kinase-C pathway, driving release of stored growth hormone from somatotrophs in discrete pulses. Because GHRP-2 acts through a pathway distinct from GHRH (which signals via cAMP), submaximal doses of a GHRP combined with GHRH produce supra-additive (synergistic) GH release in humans - a property exploited in both diagnostic testing and community stacking. GHRP-2 also stimulates appetite in a ghrelin-like fashion and can transiently raise ACTH/cortisol and prolactin, generally in a dose-dependent way; its off-target hormonal profile sits between the more cortisol/prolactin-raising GHRP-6 and the highly selective ipamorelin. Additional CD36-mediated, GH-independent cytoprotective actions have been described, but these are largely preclinical.
Researched effects
- Clinical Stimulates pulsatile growth-hormone release from the pituitary in humans
- Clinical Acts synergistically with GHRH so combined dosing releases more GH than either alone
- Clinical Reliably provokes GH secretion for diagnostic testing of GH deficiency (approved use in Japan)
- Clinical Increases food intake / appetite via ghrelin-receptor activation
- Preclinical Cytoprotective and cardioprotective effects in animal models of tissue injury
- Anecdotal Improved recovery, sleep, body composition, and skin/joint comfort with regular use
Evidence levels: Clinical (human trials) · Preclinical (animal/lab) · Anecdotal (community-reported).
Dosing reference
For research reference only — not a recommendation.
Clinical / studied dosing
For its approved diagnostic use in Japan, pralmorelin is given as a single intravenous bolus of about 1 mcg/kg to provoke a measurable GH response. Published pediatric pharmacology studies used intravenous doses on the order of 100 mcg. There is no approved or established therapeutic (repeated-use) clinical dose for GH deficiency, anti-aging, or body-composition goals - the human data establish acute GH-releasing capacity and tolerability, not a validated treatment regimen.
Community-reported dosing (anecdotal)
Anecdotal and research-reference only; not medical advice or instruction. Community guides and forum discussion commonly describe reconstituted subcutaneous doses of roughly 100-300 mcg, taken 1-3 times daily, frequently timed away from meals and around bedtime (to align with natural GH pulses) and often stacked with a GHRH analog such as CJC-1295 or sermorelin to exploit the documented synergy. These figures reflect unverified community practice rather than tested safe or effective doses.
- Half-life
- Short. Human pharmacokinetic data show a biexponential disposition with an elimination half-life of roughly 30 minutes (about 0.55 hours) after intravenous dosing. The resulting GH pulse typically peaks around 15-60 minutes after administration.
- Routes
- subcutaneous, intramuscular, intravenous
Safety & side effects
In short-term studies GHRP-2 has generally been well tolerated, with no serious adverse events reported in pediatric GH-deficiency trials. The most consistent effects are increased hunger/food intake (a ghrelin-like action) and transient, dose-dependent rises in cortisol and prolactin; injection-site reactions and water retention are also reported anecdotally. Long-term human safety has not been established, and chronic stimulation of the GH/IGF-1 axis carries the same theoretical concerns as growth hormone itself (insulin resistance, fluid retention, and caution where there is active malignancy). Product quality is a real-world risk because research-grade material is unregulated and may be impure or mislabeled. GHRP-2 is not approved as a therapeutic drug in the US, EU, or most jurisdictions, and it is prohibited in sport by WADA. This information is for research reference only and is not a recommendation for human use.
Research summary
GHRP-2 has a stronger human evidence base than most research peptides. Its core pharmacology is well established: it reliably releases growth hormone in adults and children, its plasma half-life and dose-response have been characterized, and its synergy with GHRH is reproducibly demonstrated in humans. This body of work underpins its approval in Japan as a single-dose diagnostic agent for GH deficiency.
What is not established is GHRP-2 as a therapy. There are no large, long-term randomized trials showing that repeated GHRP-2 dosing improves clinically meaningful outcomes such as body composition, recovery, healthy aging, or cardiac function in humans; the cardioprotective and cytoprotective findings remain largely preclinical. The acute appetite-stimulating and hormone-releasing effects are real, but durable benefit and long-term safety of ongoing use are unproven.
The honest assessment is that GHRP-2 is a well-characterized GH secretagogue with genuine human pharmacology and a narrow regulatory approval for diagnosis, but it is not a validated or approved treatment. Marketing it as a proven anti-aging or performance therapy goes beyond the evidence. It should be treated as a research compound.
FAQ
- Is GHRP-2 approved or legal?
- GHRP-2 (pralmorelin) is approved in Japan only as a single-dose diagnostic agent for growth-hormone deficiency. It is not approved as a treatment for GH deficiency, anti-aging, or body composition in the US, EU, or most jurisdictions, and it is prohibited in sport by WADA. Products sold online are for research use only.
- How is GHRP-2 dosed and what is its half-life?
- Its approved diagnostic use is a single IV bolus of about 1 mcg/kg. There is no validated therapeutic dose; anecdotal community protocols cite roughly 100-300 mcg subcutaneously 1-3 times daily, often with a GHRH analog. The plasma half-life is short (about 30 minutes) and the GH pulse peaks within roughly 15-60 minutes. This is reference information, not dosing advice.
- Does GHRP-2 actually raise growth hormone?
- Yes - this is one of its best-documented effects. Human studies consistently show that GHRP-2 triggers pulsatile GH release and that it synergizes with GHRH. What is not proven is that ongoing use produces lasting benefits for recovery, body composition, or healthy aging.
- Why do people stack GHRP-2 with a GHRH analog?
- GHRP-2 and GHRH (or analogs like CJC-1295 and sermorelin) act through different receptors and signaling pathways, so combining them releases more GH than either alone. This synergy is documented in humans, which is why community protocols often pair the two; it does not, however, establish safety or efficacy of chronic use.
- Is GHRP-2 safe?
- Short-term human studies report good tolerability, with the main effects being increased appetite and transient rises in cortisol and prolactin. Long-term safety is unstudied, chronic GH-axis stimulation carries the same theoretical concerns as GH itself, and unregulated product quality is a real risk. It is not approved for human use.
References
- Bowers CY et al. Growth hormone (GH)-releasing peptide stimulates GH release in normal men and acts synergistically with GH-releasing hormone (J Clin Endocrinol Metab, 1990) (study)
- Pihoker C et al. Pharmacokinetics and pharmacodynamics of growth hormone-releasing peptide-2: a phase I study in children (J Clin Endocrinol Metab, 1998) (study)
- Laferrere B et al. Growth hormone releasing peptide-2 (GHRP-2), like ghrelin, increases food intake in healthy men (J Clin Endocrinol Metab, 2005) (study)
- Berlanga-Acosta J et al. Synthetic growth hormone-releasing peptides (GHRPs): a historical appraisal of the evidences supporting their cytoprotective effects (Clin Med Insights Cardiol, 2017) (review)
- GHRP-2 and GHRH effects on cAMP levels and GH release from cultured somatotroph/acromegalic tumour cells (pathway-independence and synergy) (study)
- Pralmorelin (GHS-R1a agonist; structure and Japanese diagnostic approval) - reference monograph (community)
All content is for research and educational use only and is not medical advice. Products are sold for laboratory research only and are not for human consumption.