GHRP-2
Also known as: Growth Hormone-Releasing Peptide-2, Pralmorelin, KP-102, GPA-748
A synthetic peptide that reliably triggers a short-term spike in growth hormone by activating the ghrelin receptor. The hormonal effect is real and measurable in humans; downstream clinical benefits are unproven. Sold as a research chemical, not an approved drug.
Not approved by the FDA for any use in the United States. Studied as a diagnostic agent (pralmorelin) for growth hormone deficiency and approved for that narrow diagnostic use in Japan, but sold elsewhere for laboratory research only.
What it is
GHRP-2 is a synthetic growth-hormone-releasing peptide — a small peptide that binds the ghrelin receptor (GHS-R1a) at the hypothalamus and pituitary and triggers a burst of growth hormone (GH). It is one of a family of “GH secretagogues” developed to raise GH without injecting GH itself. In Japan it has a narrow approved role as a diagnostic agent (pralmorelin) for testing GH deficiency; almost everywhere else it is sold as a research chemical.
What it’s approved or studied for
GHRP-2 is not FDA-approved for any therapeutic use. The best-supported thing it does — reliably provoke a GH pulse — is exactly why it was studied as a diagnostic tool, not a treatment. The muscle-building, fat-loss, recovery, and anti-aging uses it is marketed for have not been established in controlled human trials.
What human evidence exists
There is genuine human pharmacology data here, which is why the GH effect is graded higher than a purely preclinical compound. Controlled studies show GHRP-2 produces a sharp, dose-dependent rise in GH (Grade C — a measurable biomarker effect, not a proven clinical benefit), and a small infusion study showed it increases food intake much like ghrelin (Grade C). What is missing is the step that matters: no adequate controlled trials show those hormonal changes translate into better body composition, strength, recovery, or healthspan (Grade E for those outcomes). Long-term safety is Grade U — unknown.
The major unknowns
The central unknown is whether raising GH acutely with GHRP-2 produces any durable benefit that outweighs its risks. Long-term effects of repeated GH-axis stimulation — on IGF-1, insulin sensitivity, cortisol, and prolactin — are not characterized in humans. Because research-chemical supply is unregulated, the identity and purity of any given vial are also uncertain.
Most important safety considerations
The honest answer to “is it safe long-term?” is that no one knows — there is no controlled long-term human safety data. It can transiently raise cortisol and prolactin, and sustained IGF-1 elevation is a theoretical concern. It is prohibited in sport under WADA’s S2 category, product quality is uncontrolled, and it is not a legal therapeutic. This page summarizes the research record; it is not medical advice or an endorsement of use.
Evidence by outcome
Each outcome is graded on its own evidence — a compound can be strong for one use and unproven for another. See how we grade.
Reliably raises GH in short human studies — a biomarker effect, not a clinical outcome. — Human pharmacology and diagnostic-testing studies consistently show a sharp, dose-dependent GH pulse after dosing. This is a measurable pharmacodynamic effect; it does not by itself establish any health benefit.
Increases food intake in small human infusion studies, like ghrelin. — In a controlled infusion study in lean healthy men, GHRP-2 raised ad-libitum food intake by roughly a third versus saline — consistent with its ghrelin-mimetic action.
Not demonstrated in controlled human trials. — Despite widespread marketing claims, there are no adequate controlled trials showing GHRP-2 builds muscle or improves body composition in people.
No human evidence.
Unknown — no controlled long-term human safety data exist. — Repeated GH-axis stimulation can raise IGF-1 and affect glucose handling, cortisol, and prolactin; the long-term consequences in humans are uncharacterized.
Safety
Common adverse effects
- Not well characterized in humans; transient increases in cortisol and prolactin reported at higher doses; injection-site reactions reported anecdotally
- flushing
- increased hunger
Serious risks
- Unknown long-term risk profile; sustained IGF-1 elevation and effects on insulin sensitivity are theoretical concerns; unregulated product quality and contamination risk
Contraindications
- No human contraindication data; not approved for human therapeutic use
References
- Bowers CY et al. / Laferrère B et al. Growth hormone releasing peptide-2 (GHRP-2), like ghrelin, increases food intake in healthy men. J Clin Endocrinol Metab (2005)
- Pihoker C et al. Pharmacokinetics and pharmacodynamics of growth hormone-releasing peptide-2: a phase I study in children. J Clin Endocrinol Metab (1998)
- WADA. The Prohibited List (S2 Peptide Hormones, Growth Factors, Related Substances and Mimetics)