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Research peptide — not a dietary supplement
GHRP-2 is a research compound, not a regulated dietary supplement. It is typically administered by injection and sold “for research use only.” The evidence below is largely preclinical (animal and in-vitro) or early-stage, so no evidence score is assigned. This page is provided for transparency and education — it is not a recommendation to use. Consult a qualified healthcare provider, and be aware that purity, dosing, and legal status vary by jurisdiction.
What the evidence says
Most GHRP-2 studies are mechanism or observational rather than RCTs that measure a clinical effect — keep findings provisional.
Most evidence is from mixed-quality randomised trials published 2010–2023 with a typical study size of 26 participants.
Based on 8 studies · 2 RCTs · 187 total participants
Confidence
LowBy outcome
The current evidence for GHRP-2 is insufficient to assign an evidence score, based on 8 indexed studies. A synthetic ghrelin-receptor (GHS-R1a) agonist that triggers a pulse of growth hormone from the pituitary. Honest appraisal: the human data are short biomarker studies (acute GH/IGF-1 rises and a validated diagnostic GH-stimulation test) — it's approved ONLY in Japan as a diagnostic agent. The injectable/intranasal use sold grey-market for muscle, fat loss, and anti-aging has NO outcome trials, and it's banned in sport by WADA. Representative study: PMID 23485864.
The commonly studied dose of GHRP-2 is No legitimate self-administration dose exists. Japan's approved DIAGNOSTIC use is a single 100 µg IV dose for a GH-stimulation test. Grey-market injectable protocols (~100 µg subcutaneous, 1-3×/day) are unapproved and unvalidated.. Individual needs vary — start at the lower end of the range and adjust based on how you respond.
Mecasermin (IGF-1)
Mostly mechanism / observationalThe pharmaceutical-grade version of IGF-1 — an FDA/EMA-approved prescription injectable, but approved ONLY for a rare childhood growth disorder (severe primary IGF-1 deficiency / Laron syndrome), where it genuinely raises height velocity in clinical trials. It is the regulated counterpart to the grey-market igf-1-lr3 peptide bodybuilders inject, and shares the same core risks. Crucially, there is NO trial supporting its off-label use for muscle, performance, or anti-aging in healthy adults — and IGF-1's documented harms (hypoglycemia, intracranial hypertension, lymphoid/tonsillar hypertrophy, and a theoretical cancer concern because IGF-1 is mitogenic) are real. Not a dietary supplement, not a longevity drug.
Last reviewed June 2026 · evidence from 8 studies · how we score
This information is for educational purposes only. It is not a substitute for professional medical advice. Always consult a qualified healthcare provider before starting, stopping, or changing any supplement or medication.
Growth Hormone Releasing Peptide-2 (Pralmorelin)
A synthetic ghrelin-receptor (GHS-R1a) agonist that triggers a pulse of growth hormone from the pituitary. Honest appraisal: the human data are short biomarker studies (acute GH/IGF-1 rises and a validated diagnostic GH-stimulation test) — it's approved ONLY in Japan as a diagnostic agent. The injectable/intranasal use sold grey-market for muscle, fat loss, and anti-aging has NO outcome trials, and it's banned in sport by WADA.
Human data are short biomarker and diagnostic GH-stimulation studies confirming it raises GH/IGF-1; no controlled trials test the marketed muscle, fat-loss, or anti-aging claims, so evidence sits at the very low end of Emerging.
GHRP-2 (pralmorelin, originally KP-102) is a synthetic hexapeptide growth-hormone secretagogue.
It binds the growth-hormone-secretagogue receptor (GHS-R1a) — the same receptor the natural hormone ghrelin uses — on the hypothalamus and pituitary, provoking a pulse of growth hormone (GH) that in turn raises insulin-like growth factor-1 (IGF-1).
The honest evidence picture is that essentially all the human data are SHORT biomarker studies: acute and pulsatile GH-secretion experiments in healthy volunteers, a validated GH-stimulation test for diagnosing GH deficiency, and small/retrospective reports of IGF-1 rises.
On the strength of the diagnostic data, pralmorelin is approved in Japan (and only in Japan) as a single-dose intravenous diagnostic agent for GH-secretion deficiency.
It is NOT an approved treatment anywhere for the things it is actually sold for — added muscle, fat loss, recovery, and anti-aging — and there are no long-term, controlled outcome trials testing those claims.
What the literature does establish: GHRP-2 reliably raises GH and IGF-1 in the short term, also stimulates appetite (a ghrelin-receptor effect), and tends to raise cortisol and prolactin alongside GH.
Beyond that, the marketed bodybuilding/anti-aging injectable is a grey-market research chemical: unapproved, sourced from unregulated vendors of variable purity (forensic labs repeatedly find GHRP-2 and glycine-analogue adulterants in black-market vials and 'supplements'), with unknown long-term safety.
It is on the World Anti-Doping Agency's Prohibited List. Overall evidence for the marketed uses is very low — the score here renders UNSCORED on purpose.
GHRP-2 binds the growth-hormone-secretagogue receptor GHS-R1a — the same receptor as the natural hormone ghrelin — on the hypothalamus and pituitary. Confirmed in human pituitary tissue and by receptor-binding assays.
Receptor activation provokes a pulse of growth hormone from the pituitary, partly by opposing somatostatin and amplifying endogenous GHRH drive. The release is pulsatile and subject to negative feedback rather than a flat elevation.
How GHRP-2 works — from molecular targets to health outcomes. Click an edge to see supporting research.This visualization is in beta — pathways are being refined and expanded.
Tap node to isolate • Pinch to zoom • Tap edge for research
No legitimate self-administration dose exists. Japan's approved DIAGNOSTIC use is a single 100 µg IV dose for a GH-stimulation test. Grey-market injectable protocols (~100 µg subcutaneous, 1-3×/day) are unapproved and unvalidated.
Can be taken without food
| Form | Type |
|---|---|
| 💊None — diagnostic IV use is clinician-administered; there is no validated self-use form | Recommended |
| 💊GHRP-6 | Alternative |
| 💊Ipamorelin | Alternative |
| 💊Sermorelin | Alternative |
| 💊Ibutamoren (MK-677) | Alternative |
Other GH secretagogues are also grey-market research chemicals with the same evidence and regulatory caveats; pralmorelin is distinctive only in having a diagnostic approval in Japan.
Compare GHRP-2 vs GHRP-6 →Minimum: 1 weeks
Optimal: 4 weeks
Cycling: Not required
Note: No evidence-based timing exists for the marketed uses. The only validated context is a clinician-administered single diagnostic dose.
Dose-response data unavailable. The current published research for GHRP-2 does not provide sufficient dose-specific outcome data to generate reliable dose-response curves.
Refer to the Dosage & Timing section above for recommended dose ranges based on available evidence.
Reliably produces an acute GH pulse and raises IGF-1 over days to weeks in human studies. This is a biomarker change — not a demonstrated clinical benefit.
Ghrelin-receptor agonism increases hunger and food intake. Can be a desired or undesired effect depending on context.
GHRP-2 stimulates cortisol and prolactin alongside GH — an off-target endocrine effect, not a clean GH releaser.
Muscle, fat-loss, recovery, and anti-aging claims have no long-term controlled trials. Only short biomarker studies and Japan's diagnostic approval exist.
Avoid — raising GH/IGF-1 is a theoretical proliferation risk.
Avoid — GH secretagogues can worsen glucose control.
Prohibited at all times under the WADA Code (GH secretagogues).
Not studied — avoid.
GH secretagogues can decrease insulin sensitivity and raise blood glucose, potentially opposing antidiabetic therapy.
GHRP-2 itself raises cortisol; additive effects on the HPA axis and glucose are plausible.
Tip: Expected ghrelin-receptor effect; can drive unwanted weight gain
Tip: Off-target endocrine effect; monitor if used clinically
Tip: Monitor glucose; avoid in glucose-intolerant individuals
Tip: Classic GH-excess-type effects; reduce/stop
Tip: Inherent to unregulated injectable sourcing and self-injection
Timing is flexible for GHRP-2 — consistent daily use matters more than the time of day. Grey-market injectable protocols are typically dosed on an empty stomach (food, especially carbohydrate/fat, blunts the GH response).
GHRP-2 should be used with caution — talk to a healthcare provider before taking it. The most commonly reported side effects are increased appetite / hunger, raised cortisol and prolactin, reduced insulin sensitivity / higher blood glucose. Use caution if any of these apply to you: Pregnancy / breastfeeding (avoid — not studied); Active or history of cancer (GH/IGF-1 elevation is a theoretical proliferation concern); Diabetes / impaired glucose tolerance (GH secretagogues can reduce insulin sensitivity).
Insulin (bodybuilding use)
Mostly mechanism / observationalInsulin is a life-saving prescription hormone for diabetes — and, used illicitly by bodybuilders as an off-label 'anabolic,' one of the most dangerous performance drugs in existence. The theory is nutrient partitioning: insulin drives glucose and amino acids into muscle and suppresses muscle-protein breakdown. But there is NO controlled evidence that insulin builds muscle or improves performance in healthy, non-diabetic athletes — and a non-diabetic who injects it risks profound, sometimes FATAL hypoglycemia (coma, seizures, brain injury, death), plus fat gain. This is a harm-reduction reference documenting a popular, deadly misuse, NOT a recommendation and NOT a dietary supplement.
The GH pulse drives hepatic IGF-1, the surrogate marker for GH action. Repeated dosing raises IGF-1 in short human studies; durable or long-term effects are unstudied.
As a ghrelin-receptor agonist, GHRP-2 increases hunger and food intake — shown in animals and in case reports of intranasal use in wasting states.
As an agent that perturbs pituitary secretion (GH, cortisol, prolactin), interactions with other endocrine therapies are possible and unstudied for chronic use.