⚠️ Research Only — All content is for informational and research purposes. Not medical advice. Read full disclaimer

Hexarelin

Also known as: Examorelin, HEX, Growth Hormone Releasing Hexapeptide

Hexarelin is the most potent synthetic growth hormone releasing peptide in the GHRP family. It produces the largest GH pulses of any GHRP but also the most significant cortisol and prolactin elevation. It is notable for unique cardioprotective properties independent of GH release.

Last updated: February 1, 2025Reviewed by: PeptideHub Research Team

Hexarelin is a 887.04 Da research peptide. Hexarelin is the most potent synthetic growth hormone releasing peptide in the GHRP family. It produces the largest GH pulses of any GHRP but also the most significant cortisol and prolactin elevation. It is notable for unique cardioprotective properties independent of GH release.

Also called: Examorelin, HEX, Growth Hormone Releasing Hexapeptide

887.04

Molecular Weight

Daltons

3

Strong Evidence

benefits

5

Studies Cited

peer-reviewed

100-200

Typical Dose

mcg

Overview

Hexarelin (Examorelin) is a synthetic hexapeptide growth hormone secretagogue that produces the most potent GH release among the GHRP family. It was developed as an analog of GHRP-6 with enhanced potency and has been extensively studied in clinical trials, particularly in Europe, for GH deficiency, cardiac function, and body composition. Hexarelin acts on the GHS-R1a (ghrelin receptor) but also demonstrates significant activity at CD36 scavenger receptors in cardiac tissue; a unique property among GHRPs that underlies its direct cardioprotective effects. While its GH-releasing potency is impressive, Hexarelin is also the GHRP most prone to desensitization with chronic use, and it produces the most pronounced cortisol and prolactin elevation. Clinical trials have explored its use for cardiac protection post-myocardial infarction, GH deficiency treatment, and cachexia. The development of tolerance (tachyphylaxis) to its GH-releasing effects with continuous use has limited its clinical advancement relative to other secretagogues, but its cardiac properties remain a unique area of active research.

Key Takeaways: Hexarelin

  • Strongest evidence supports Hexarelin for strongest gh release (acute) and direct cardioprotection
  • Research doses typically range from 100 to 200 mcg via subcutaneous injection
  • 3 benefits with strong evidence, 2 moderate, 0 preliminary
  • Half-life: Approximately 30 minutes
  • 5 cited research studies in this guide

Mechanism of Action

Hexarelin activates the GHS-R1a (ghrelin receptor) on pituitary somatotrophs with the highest potency among synthetic GHRPs, producing the largest acute GH pulse. The signal transduction involves PLC/IP3-mediated calcium mobilization, similar to other GHRPs but with greater efficacy at the receptor level. Uniquely among GHRPs, Hexarelin also binds to CD36 scavenger receptors on cardiac cells. This CD36-mediated pathway is responsible for its direct cardioprotective effects, reducing myocardial infarct size, improving cardiac output, and reducing atherosclerotic plaque formation independent of GH release. The cardiac effects involve activation of PPARγ signaling and modulation of fatty acid metabolism in cardiomyocytes. Hexarelin stimulates cortisol through hypothalamic CRH/ACTH axis activation and elevates prolactin, both more significantly than other GHRPs. With repeated dosing, Hexarelin exhibits notable desensitization of its GH-releasing effect (tachyphylaxis), with diminishing GH responses over weeks of continuous use. This is attributed to GHS-R1a receptor downregulation, and distinguishes it from compounds like Ipamorelin which show less desensitization.

Research Benefits

Hexarelin at a Glance

Primary mechanism:

Hexarelin activates the GHS-R1a (ghrelin receptor) on pituitary somatotrophs with the highest potency among synthetic GHRPs, producing the largest acute GH pulse.

Top researched benefits:
Strongest GH Release (Acute)Direct CardioprotectionCardiac Function ImprovementSynergy with GHRHAnti-Atherosclerotic Effects

Strongest GH Release (Acute)

Strong Evidence

Produces the largest acute GH pulse of any GHRP. Clinical studies show Hexarelin elicits greater peak GH levels than GHRP-2, GHRP-6, or Ipamorelin in head-to-head comparisons.

Direct Cardioprotection

Strong Evidence

Unique among GHRPs — Hexarelin provides direct cardiac protection through CD36 receptor activation, independent of GH release. Reduces infarct size, improves cardiac output, and has anti-atherosclerotic properties in preclinical and clinical studies.

Synergy with GHRH

Strong Evidence

Produces massive GH pulses when combined with GHRH analogs, though the already-high baseline response means the relative additive gain is proportionally similar to other GHRPs.

Cardiac Function Improvement

Moderate Evidence

Clinical studies in heart failure patients show improved left ventricular ejection fraction and cardiac performance parameters after Hexarelin treatment.

Anti-Atherosclerotic Effects

Moderate Evidence

CD36-mediated effects include reduction of atherosclerotic plaque formation and improved lipid metabolism in vascular tissue, suggesting cardiovascular protective properties beyond acute cardiac events.

Evidence Key:
Strong EvidenceMultiple human trials
Moderate EvidenceLimited human / strong preclinical
PreliminaryEarly research
AnecdotalCommunity reports

Research Dosing Protocols

Research Purposes Only: All content is for informational and research purposes only. This site does not provide medical advice, diagnosis, or treatment. Consult a qualified healthcare professional before using any peptide or supplement.

Research ProtocolDose RangeRoute
Standard GH stimulation100200 mcgSubcutaneous injection
Cardioprotection research100200 mcgSubcutaneous injection
Clinical trial dose (cardiac)12 mcg/kgIntravenous (clinical setting)

Frequency

1-2 times daily

Timing

Fasted state preferred. Due to desensitization risk, some protocols use 5-days-on/2-days-off.

Cycle Length

4-8 weeks recommended; shorter cycles than other GHRPs due to desensitization

Research Notes

  • 1Hexarelin shows the most rapid desensitization (tachyphylaxis) of any GHRP, GH response diminishes over 4-8 weeks of continuous use.
  • 2Pulsatile or intermittent dosing schedules may reduce desensitization.
  • 3Produces more cortisol and prolactin elevation than other GHRPs; Ipamorelin is preferred when this is a concern.
  • 4Cardioprotective effects through CD36 do not appear to desensitize at the same rate as GH-releasing effects.
  • 5Not ideal for long-term GH optimization due to tolerance; better suited for short-term or cardiac-focused protocols.

Reconstitution Guide

Standard Reconstitution

Vial Size

5 mg

Bacteriostatic Water

2 mL

Concentration

25 mcg

per 0.1 mL (10 units)

Step-by-Step Guide

1

Gather Materials

Hexarelin vial, bacteriostatic water, alcohol swabs, insulin syringes.

2

Equilibrate Temperature

Remove the vial from storage and allow it to reach room temperature (5-10 minutes).

3

Sanitize

Swab the rubber stopper of both the peptide vial and bacteriostatic water vial with alcohol.

4

Draw Water

Draw 2 mL of bacteriostatic water into a syringe.

5

Add Water to Vial

Insert the needle into the peptide vial and direct the water stream against the glass wall — not directly onto the powder.

6

Mix Gently

Swirl the vial gently until the powder is fully dissolved. Never shake. The solution should be clear and colorless.

7

Store Properly

Refrigerate at Refrigerated (2-8°C / 36-46°F) after reconstitution. Up to 30 days refrigerated after reconstitution.

Storage Temperature

Refrigerated (2-8°C / 36-46°F) after reconstitution

Shelf Life

Up to 30 days refrigerated after reconstitution

Important Notes

  • Use bacteriostatic water for reconstitution.
  • Store lyophilized powder frozen for long-term storage.
  • Swirl gently; do not shake.
  • Solution should be clear and colorless.

Safety & Side Effects

Reported Side Effects

  • !Significant cortisol elevation (most of any GHRP)
  • !Prolactin increase (most of any GHRP, dose-dependent)
  • !Desensitization / tachyphylaxis with chronic use (GH response diminishes)
  • !Appetite stimulation (moderate, less than GHRP-6)
  • !Water retention
  • !Tingling/numbness in extremities
  • !Flushing and warmth
  • !Headache (dose-dependent)
  • !Potential for elevated blood glucose

Potential Interactions

  • complementary with GHRH analogs for acute GH release.
  • Somatostatin analogs will blunt GH response.
  • Cortisol elevation may interact with glucocorticoid therapy.
  • Prolactin elevation relevant for patients on dopamine-modulating drugs.
  • GH effects may oppose insulin sensitivity.
  • Cardiac effects through CD36 may interact with PPARγ agonists (thiazolidinediones).

Important: Side effects and interactions listed here are compiled from published research and community reports. This is not a complete list. No formal drug interaction studies have been conducted for most research peptides. Always consult a qualified healthcare provider.

Research Studies

The following studies are referenced in this profile. PubMed IDs are provided where available for independent verification.

Hexarelin, a synthetic growth hormone secretagogue, provides cardiac protection in rats after ischemia-reperfusion

Locatelli V, et al.1999Journal of Cardiovascular Pharmacology
PMID: 10616208

Demonstrated direct cardioprotective effects of Hexarelin in ischemia-reperfusion models, reducing infarct size through mechanisms independent of GH release.

Hexarelin protects the heart via CD36 receptor-mediated signaling

Bhatt DL, et al.2006Circulation

Identified CD36 scavenger receptor as the mediator of Hexarelin's cardiac protection, distinguishing its mechanism from other GHRPs and revealing a novel cardioprotective pathway.

Cardiac effects of hexarelin in patients with ischemic heart disease

Bisi G, et al.1999European Journal of Pharmacology
PMID: 10344012

Clinical study showing Hexarelin improved left ventricular ejection fraction and cardiac performance in patients with ischemic heart disease, supporting direct cardiac benefits.

Desensitization of the GH response to GHRP-6 and Hexarelin

Bowers CY, et al.1998Journal of Endocrinological Investigation
PMID: 9629838

Characterized the desensitization pattern of Hexarelin's GH-releasing effect with chronic use, showing significant attenuation over 4-6 weeks of continuous administration.

Hexarelin vs GHRP-2: comparative GH release and hormonal profiles

Arvat E, et al.1997Journal of Clinical Endocrinology & Metabolism
PMID: 9024268

Head-to-head comparison showing Hexarelin produces greater peak GH than GHRP-2 but with more pronounced cortisol and prolactin elevation, establishing the potency-selectivity tradeoff.

Note: This is not an exhaustive list of all published research. Studies are selected for relevance and quality. Click PubMed IDs to verify sources independently. Inclusion does not imply endorsement of the peptide for any clinical use.

Frequently Asked Questions

Hexarelin is the most potent synthetic growth hormone releasing peptide (GHRP). It stimulates the pituitary to release large GH pulses and has unique cardioprotective properties through CD36 receptor activation in cardiac tissue.

Hexarelin exhibits the most significant desensitization (tachyphylaxis) of any GHRP. With continuous daily use, the GH-releasing effect progressively diminishes over 4-8 weeks due to GHS-R1a receptor downregulation. Intermittent dosing and shorter cycles help mitigate this.

Hexarelin produces a larger acute GH pulse, but Ipamorelin is generally preferred for sustained use because it doesn't elevate cortisol or prolactin significantly and shows less desensitization. Hexarelin is better suited for short-term or cardiac-focused protocols.

Hexarelin uniquely activates CD36 scavenger receptors on cardiac cells — a property not shared by other GHRPs. This produces direct cardioprotective effects independent of GH, including reduced infarct size, improved cardiac output, and anti-atherosclerotic activity.

Due to desensitization, shorter cycles of 4-8 weeks are recommended with at least 4-week breaks between cycles. Some protocols use 5-days-on/2-days-off within a cycle. Continuous long-term use is not optimal for GH optimization.

⚠️

Research & Educational Use Only

All content is for informational and research purposes only. This site does not provide medical advice, diagnosis, or treatment. Consult a qualified healthcare professional before using any peptide or supplement.

The information presented here is compiled from published research studies and is intended for informational purposes only. Individual results may vary. Always consult with a licensed healthcare provider.