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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.
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 high-quality randomised trials published 1995–2023 with a typical study size of 56 participants.
Based on 47 studies · 41 RCTs · 136 total participants
Confidence
Moderate confidenceBy outcome
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.
41 rigorous studies
41 randomized trials · 0 meta-analyses · 0 systematic reviews
Our evidence rating for GHRP-2 is accountable to this entire body of rigorous research indexed in PubMed — not a hand-picked subset.
PubMed · as of Jul 2026
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.
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.
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.
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.
As an agent that perturbs pituitary secretion (GH, cortisol, prolactin), interactions with other endocrine therapies are possible and unstudied for chronic use.
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
The current evidence for GHRP-2 is insufficient to assign an evidence score, based on 24 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.
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).
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.
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.
ACE-031
Mostly mechanism / observationalAn investigational myostatin/activin 'trap' whose only human trial in patients was STOPPED for safety. ACE-031 is a fusion protein of the activin receptor type IIB (ActRIIB) extracellular domain and an IgG1-Fc, engineered by Acceleron Pharma to soak up myostatin and related ligands and thereby release the brake on muscle growth. It has real human data — a single-dose study in healthy postmenopausal women showed a genuine ~3% gain in lean mass — but its phase 2 trial in boys with Duchenne muscular dystrophy was HALTED after the second dosing regimen because of bleeding-related safety signals (nosebleeds/epistaxis and telangiectasias, dilated surface blood vessels). It is NOT an approved drug, development was discontinued, and anything sold grey-market under this name is unregulated. This entry exists to inform, not to recommend.
CJC-1295
Mostly mechanism / observationalA synthetic long-acting analog of growth-hormone-releasing hormone (GHRH), promoted online to raise GH and IGF-1 for muscle, fat loss and 'anti-aging'. Honest appraisal: the only real human data are two small early-phase pharmacokinetic / safety studies from ~2006 that showed it raises GH and IGF-1 for days — they were never followed by efficacy trials in muscle, body composition or aging. There are NO human outcome RCTs. It is not a dietary supplement: it is sold 'for research use only', is injectable, and is banned by WADA. The original DAC version's clinical development was abandoned.
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Reviewed by Dr. Baher Al Hakim · Last reviewed June 2026 · evidence from 47 studies · how we score · editorial policy
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.
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