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Hexarelin (Examorelin)
A synthetic hexapeptide growth-hormone secretagogue (a ghrelin-receptor / GHS-R1a agonist) that triggers a sharp pituitary GH pulse. Honest appraisal: real human studies confirm it acutely raises GH, but the GH response partially DESENSITIZES (attenuates) with continued dosing, it also raises cortisol and prolactin, and there are NO body-composition or clinical outcome trials. A grey-market, research-use-only injectable — not an approved drug or a regulated dietary supplement, and WADA-banned.
Research peptide — not a dietary supplement
Hexarelin 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 Hexarelin studies are mechanism or observational rather than RCTs that measure a clinical effect — keep findings provisional.
Most evidence is from medium-quality randomised trials published 1994–2003 with a typical study size of 12 participants.
Based on 27 studies · 18 RCTs · 100 total participants
Confidence
Moderate confidenceBy outcome
Scores very low because the human evidence is short-term pharmacology only: it reliably raises GH acutely, but that response desensitizes with use and no trials show any body-composition, strength, or clinical outcome benefit.
24 rigorous studies
24 randomized trials · 0 meta-analyses · 0 systematic reviews
Our evidence rating for Hexarelin is accountable to this entire body of rigorous research indexed in PubMed — not a hand-picked subset.
PubMed · as of Jul 2026
Hexarelin (examorelin) is a synthetic enkephalin-derived hexapeptide developed in the 1990s as a growth-hormone secretagogue (GHS).
It binds the GH-secretagogue receptor GHS-R1a — the same receptor as the natural hormone ghrelin — at the pituitary and hypothalamus, and acutely evokes a large, dose-related GH pulse in humans after intravenous, subcutaneous, intranasal or even oral dosing. Two things keep the honest evidence picture modest.
First, the GH response is not durable: controlled human studies show it partially DESENSITIZES (attenuates) with continued administration — twice-daily subcutaneous hexarelin in healthy elderly subjects roughly halved the GH area-under-curve over 16 weeks (the effect was partial and reversible after a washout), and chronic intranasal dosing in children blunted the GH response within a week.
Second, hexarelin is not GH-selective: it also stimulates ACTH/cortisol and prolactin secretion.
Separately from the GH axis, hexarelin has a distinct cardiovascular pharmacology — it binds myocardial receptors and the scavenger receptor CD36, produced a GH-independent positive inotropic effect (raised left-ventricular ejection fraction) in an acute human study, and protected against post-ischemic ventricular dysfunction in animal hearts.
Crucially, all of this is short-term mechanistic / pharmacological work. There are NO trials showing hexarelin improves body composition, strength, athletic performance, or any clinical cardiac outcome in people, and its long-term safety is unknown.
It is a grey-market 'research peptide' sold for injection outside any approved medical use, carries the usual unregulated-injectable sourcing risks, and is banned by WADA. The overall evidence is best treated as UNSCORED / emerging.
Binds the GH-secretagogue receptor GHS-R1a — the ghrelin receptor — at the pituitary and hypothalamus, partly by counteracting somatostatin tone, to evoke a sharp, dose-related GH pulse.
Binds specific myocardial receptors and the scavenger receptor CD36, the basis for GH-independent cardiac effects seen in preclinical models and one acute human study.
Not GH-selective — also stimulates the hypothalamic-pituitary-adrenal axis (ACTH and cortisol) and prolactin, an off-target endocrine effect of the GHS class.
How Hexarelin 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 — not studied.
Avoid — GH/IGF-1 elevation is theoretically growth-promoting.
Prohibited — GH secretagogues are banned by WADA at all times.
Do not self-experiment; cardiovascular and glucose effects are real and unsupervised use is unsafe.
Hexarelin stimulates ACTH and cortisol; its endocrine effects interact with glucocorticoids and HPA-axis agents (e.g. blunted by dexamethasone, exaggerated in Cushing's).
GH elevation can oppose insulin action and raise glucose, theoretically working against glucose-lowering therapy.
Stacking with other GHS or exogenous GH compounds compounds GH/IGF-1 elevation and its associated risks; not studied.
Tip: Inherent to the GHS class; no validated mitigation — a reason not to use chronically
Tip: Off-target endocrine effect of the peptide
Tip: Partial and reversible after a washout; reflects receptor desensitization, not tolerance to a benefit
Tip: Inherent to grey-market injectables; sterility and purity are unverified
Tip: Class effect of GH elevation; not well characterized for hexarelin specifically
The current evidence for Hexarelin is insufficient to assign an evidence score, based on 10 indexed studies. A synthetic hexapeptide growth-hormone secretagogue (a ghrelin-receptor / GHS-R1a agonist) that triggers a sharp pituitary GH pulse. Honest appraisal: real human studies confirm it acutely raises GH, but the GH response partially DESENSITIZES (attenuates) with continued dosing, it also raises cortisol and prolactin, and there are NO body-composition or clinical outcome trials. A grey-market, research-use-only injectable — not an approved drug or a regulated dietary supplement, and WADA-banned. Representative study: PMID 10990150.
The commonly studied dose of Hexarelin is No established or approved human dose. Research studies used roughly 1-2 µg/kg IV acutely, or ~60 µg/kg intranasally / twice-daily subcutaneous injections in trials. Grey-market use is unregulated and not endorsed.. Individual needs vary — start at the lower end of the range and adjust based on how you respond.
Timing is flexible for Hexarelin — consistent daily use matters more than the time of day. Acute GH-stimulation studies dosed IV/SC without regard to meals.
Hexarelin should be used with caution — talk to a healthcare provider before taking it. The most commonly reported side effects are raised cortisol / ACTH, raised prolactin, attenuating GH response (desensitization). Use caution if any of these apply to you: Pregnancy and breastfeeding (not studied — avoid); Active or prior cancer (GH/IGF-1 elevation is theoretically growth-promoting); Competitive athletes subject to anti-doping testing (WADA-banned).
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 27 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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