Hexarelin
Also known as: Examorelin · L-692,585 · growth hormone releasing peptide-6 analogue
A synthetic hexapeptide growth-hormone-releasing peptide with the most potent GH-releasing activity in the class, and distinctive cardioprotective effects mediated by a non-GH-mediated mechanism.
Hexarelin is the most potent GHRP-family compound with distinctive cardioprotective effects via cardiac CD36 receptor engagement independent of the GH-axis mechanism.
Evidence tier: C — preclinical / mechanistic evidence only
- Category
- Sleep & Recovery
- Half-life
- Approximately 55 minutes plasma
Section 1
Overview
Hexarelin (examorelin) is a synthetic hexapeptide growth-hormone-releasing peptide developed by the Ghigo laboratory in Italy as one of the more potent GHRP-family compounds. Its distinctive research profile is characterised by two features: substantially higher GH-releasing potency than the earlier GHRPs (GHRP-2, GHRP-6), and independent cardioprotective effects mediated through a non-GH-mediated mechanism involving cardiac CD36 receptor engagement.
In research-peptide practice, Hexarelin is used both as a GH-axis research tool (typically in combination with GHRH analogues) and as a research tool for the cardioprotective mechanism. The cardioprotective research angle extends the compound's research applications beyond the primary GH-axis endocrine-and-cognitive-relevance research into cardiovascular research contexts.
Cognitive-relevance research applications follow the same GH-axis framework as the other GHRP-family compounds — sleep-onset GH pulse augmentation with indirect cognitive-relevance via sleep-mediated memory consolidation. The compound's higher GH-releasing potency provides a research-tool advantage for research applications requiring strong GH-axis stimulation.
Section 2
Discovery & History
- Developed by the Ghigo laboratory in Italy in the 1990s as a next-generation GHRP with substantially higher GH-releasing potency than GHRP-2 and GHRP-6.
- Underwent extensive academic research characterisation across the 1990s and 2000s for both GH-axis pharmacology and the independent cardioprotective mechanism.
- Cardioprotective effects mediated through cardiac CD36 receptor engagement were characterised as a distinctive mechanism separate from the primary GH-releasing pharmacology.
- Did not progress to marketing authorisation despite substantial mechanistic characterisation.
- Continues to be used in research-peptide practice as a potent GH-axis research tool and in cardiovascular research contexts.
Section 3
Mechanism of Action
- 1Ghrelin-receptor (GHSR-1a) agonism on pituitary somatotroph cells, driving GH release from the pituitary with substantially higher potency than earlier GHRPs.
- 2Reduced but not absent off-target effects on cortisol, prolactin, and ACTH release relative to the earlier GHRPs — intermediate between the highly-selective Ipamorelin and the earlier less-selective GHRP-2 and GHRP-6.
- 3Independent cardioprotective mechanism via cardiac CD36 receptor engagement — a distinctive non-GH-mediated pathway that operates through the cardiac scavenger-receptor system rather than the primary GH-axis pathway.
- 4Combined pulse-effect with GHRH analogues — Hexarelin provides potent ghrelin-receptor arm signalling that potentiates the GHRH-receptor arm signalling from CJC-1295 or Sermorelin.
- 5Systemic GH-mediated effects — increased IGF-1 production, downstream metabolic and tissue-repair effects, and CNS-relevant IGF-1 signalling.
- 6Sleep-onset GH pulse augmentation providing the indirect cognitive-relevance mechanism via sleep-mediated memory consolidation.
- 7Reported effects on body composition (lean mass, adiposity) via the systemic GH mechanism.
Section 4
Researched Benefits
Findings reported in the published preclinical and clinical literature. Effects in research contexts do not constitute claims of therapeutic benefit in humans.
- 1Highest GH-releasing potency in the GHRP class — appropriate for research applications requiring strong GH-axis stimulation.
- 2Distinctive cardioprotective mechanism via cardiac CD36 receptor engagement — a research-tool niche unshared by other GHRPs.
- 3Effective research-tool combination with GHRH analogues for physiological GH-pulse research.
- 4Reported effects on body composition, tissue-repair markers, and metabolic parameters in research applications.
- 5Sleep-onset GH pulse augmentation with indirect cognitive-relevance via sleep-mediated memory consolidation.
- 6Substantial academic research characterisation across GH-axis and cardiovascular research contexts.
- 7Distinctive research applications extending beyond the primary GH-axis endocrine research into cardiovascular research.
Section 5
Theoretical Dosing & Protocols
| Route | Dosage | Frequency | Duration | Source |
|---|---|---|---|---|
| Subcutaneous injection (research) | 1.5 micrograms per kg, dose used in Maccario et al., 2002 (PMID 11888836), a study in six healthy young men | Two or three times in one day | One day of treatment | Maccario et al., 2002 (PubMed 11888836) |
Note: In the cited study, prior hexarelin administration blunted the GH response to a subsequent intravenous hexarelin dose. The dose shown is a single-day research schedule, not a recommendation.
Section 6
Administration Routes
- Subcutaneous injection — the primary research route.
- Intramuscular administration in some research contexts.
- Oral administration is not viable.
- Intranasal administration explored in some research applications but not the standard route.
Section 7
Safety Profile
Commonly reported
- · Injection-site reactions with subcutaneous administration.
- · Occasional headache during initial dosing.
- · Mild transient effects on cortisol, prolactin, and ACTH (more pronounced than for Ipamorelin) — the reduced-but-not-absent off-target effect.
- · Fluid retention and mild peripheral oedema — expected GH-mediated effect.
- · Occasional mild fatigue or drowsiness reported after dosing.
Rare / theoretical
- · Tolerance development to the GH-releasing effect with chronic use — the reason chronic protocols are typically shorter than for Ipamorelin.
- · Diabetes precipitation or worsening of glycaemic control in susceptible research subjects.
- · GH-mediated effects on cardiac hypertrophy in chronic high-dose research.
- · Theoretical GH-mediated tumour-growth concerns in active malignancy.
- · Rare hypersensitivity reactions.
Contraindications
- · No entry for Hexarelin was found in the electronic medicines compendium (emc) on 17 October 2026.
- · Active malignancy — theoretical contraindication via the GH-axis mechanism.
- · Pregnancy and lactation.
- · Severe uncontrolled diabetes.
Section 8
UK & EU Regulatory Context
United Kingdom
No entry for Hexarelin was found in the electronic medicines compendium (emc) on 17 October 2026. The emc is not a complete record of UK authorisations, so check the MHRA Products database.
European Union
Not approved by the EMA.
Section 9
Clinical Studies Summary
Hexarelin GH-releasing potency characterisation
Clinical pharmacology characterisation of Hexarelin's GH-releasing potency demonstrating substantially higher activity than GHRP-2 and GHRP-6 at equivalent doses. Established the compound's positioning as the most potent GHRP-family research tool.
Hexarelin cardioprotective mechanism — CD36 receptor engagement
Molecular pharmacology characterisation of Hexarelin's cardioprotective mechanism via cardiac CD36 receptor engagement, demonstrating the distinctive non-GH-mediated pathway that operates through the cardiac scavenger-receptor system rather than the primary GH-axis pathway. Established the compound's distinctive cardiovascular research application niche.
Hexarelin in aged-population GH-axis research
Clinical research applications of Hexarelin in age-related GH decline populations, reporting GH-axis restoration and modest secondary effects on body composition and metabolic parameters. Extends the GH-axis research applications into aged-population contexts.
Hexarelin cardioprotection in ischaemia-reperfusion models
Preclinical cardiovascular research characterising Hexarelin's cardioprotective effects in ischaemia-reperfusion injury models, reporting reduced infarct volume and preserved cardiac function in treated cohorts via the CD36-mediated mechanism.
Section 10
Frequently Asked Questions
Section 10a
Practical Research Guidance
Cycle guidance
Reconstitution & storage
UK sourcing notes
Section 11
Sourcing for Laboratory Research
Sourcing Hexarelin for laboratory research
Researchers in the United Kingdom and elsewhere typically obtain Hexarelin from specialist research-chemical suppliers. Purity, third-party testing, and supplier transparency are the principal differentiators worth evaluating before placing an order. The two suppliers below are commonly referenced in UK research contexts.
Reminder: this page is educational. Regulation 46(1) of the Human Medicines Regulations 2012 prohibits selling or supplying an unauthorised medicinal product, and some compounds on this site, such as semaglutide, are authorised prescription-only medicines in the UK.