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Hexarelin

Growth Hormone

Also known as: Examorelin, HEX

Half-life: ~55 minutes

Last reviewed:  ·  Published:

Muscle GrowthAnti Aging

Overview

Hexarelin (also known as Examorelin) is a synthetic hexapeptide growth hormone secretagogue closely related to GHRP-6, with a single amino-acid modification (2-methyl-tryptophan substitution) that gives it significantly greater potency and a longer duration of action. On a milligram-for-milligram basis, Hexarelin produces the most powerful acute GH release of any peptide in the GHRP family. Like other ghrelin-receptor agonists it works through GHS-R1a, but it also binds with appreciable affinity to the CD36 scavenger receptor, which is the basis for its observed cardioprotective effects independent of the GH axis.

A distinctive feature of Hexarelin is the body of research showing direct cardiovascular benefits — protection against ischemia-reperfusion injury, improved left-ventricular function in models of dilated cardiomyopathy, and anti-fibrotic effects in cardiac tissue. These effects are mediated by CD36 in the heart and are not duplicated by GHRH analogs or by IGF-1 elevation alone. Several Phase 1 and 2 clinical trials have explored Hexarelin in heart-failure populations.

The trade-off for Hexarelin's potency is the most pronounced cortisol and prolactin elevation of any commonly used GHRP, plus the strongest tendency toward tachyphylaxis with chronic dosing. Receptor desensitization can blunt the response substantially after 3-4 weeks of continuous high-frequency use, so cycling (e.g., 4 weeks on, 4 weeks off) is standard practice.

History

Hexarelin was developed in the early 1990s by researchers including Romano Deghenghi and was characterized in seminal work by Ezio Ghigo's group at the University of Turin. By the mid-1990s it had been shown to be the most potent member of the GHRP family. Pharmacia & Upjohn briefly explored it as a clinical candidate but did not pursue regulatory approval. Subsequent research at McGill University (Yvan Bouchard, Yves Marcel) and elsewhere uncovered Hexarelin's direct cardiac effects via CD36, repositioning it as a candidate cardioprotective agent — a line of research that continues today.

Effects

  • Most potent acute GH release of any GHRP at equivalent doses
  • Documented cardioprotective signaling via CD36 receptor
  • Stimulates IGF-1 elevation over multi-week courses
  • Supports tissue repair and recovery
  • Mild secondary stimulation of ACTH and prolactin

Side Effects

  • Strongest cortisol and prolactin elevation of the GHRPs
  • Pronounced water retention
  • Lethargy and fatigue with chronic use
  • Rapid tachyphylaxis (response diminishes after 3-4 weeks)
  • Mild appetite stimulation

Tolerability

Hexarelin is tolerated acutely but has the harshest chronic profile of the commonly used GHRPs. The strong cortisol response is the main concern: sustained elevations can offset many of the desired anabolic and recovery effects. Tachyphylaxis is more rapid and complete with Hexarelin than with GHRP-2 or Ipamorelin, so most users restrict it to short courses or low-dose strategic use rather than as a daily long-term peptide. Cardiovascular-focused research protocols use it differently — typically lower doses and shorter cycles oriented around the CD36 pathway rather than chronic GH elevation.

Dosing Ranges

Short-course GH stimulation

Dose Range

100 mcg

Frequency

Two to three times daily (SubQ)

Duration

4 weeks maximum, then 4-week break

Combined with CJC-1295 (Mod GRF)

Dose Range

100 mcg of each

Frequency

Two to three times daily

Duration

4 weeks on / 4 weeks off

Cardioprotective research

Dose Range

1-2 mcg/kg

Frequency

Per protocol (research-only)

Duration

Variable

Dosing information is for educational purposes only. Consult a healthcare professional before using any peptide.

Reconstitution

Preparation Details

Typical Vial Size

5 mg

Water Type

Bacteriostatic water (BAC water)

Mixing Volume

2 mL

Half-Life

~55 minutes

Molecular Weight

887.0 Da

Store reconstituted vial refrigerated at 2-8°C. Use within 30 days. Subcutaneous injection on an empty stomach. Always cycle to avoid receptor desensitization.

Calculate Hexarelin dose

Where to buy Hexarelin

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Regulatory Status

FDA Status

Not FDA approved for any indication.

Legal Status

Unregulated research chemical. Prohibited by WADA.

USA

Not approved

Research-only; sold as a research chemical

EU

Not approved

Not authorized as medicinal product

UK

Not approved

Classified as research chemical

Australia

Not approved

TGA has not authorized

Canada

Not approved

Not authorized for human use

Cited Studies

Growth hormone-releasing activity of Hexarelin, a new synthetic hexapeptide, after intravenous, subcutaneous, intranasal, and oral administration in man

Ghigo E, Arvat E, Gianotti L, Imbimbo BP, Lenaerts V, Deghenghi R, Camanni F

Journal of Clinical Endocrinology & Metabolism (1994)

Foundational human characterization of Hexarelin's GH-releasing activity across multiple routes of administration, establishing it as the most potent GHRP studied in humans at the time.

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Identification of CD36 as the receptor for the cardiac effects of growth hormone-releasing peptides

Bodart V, Febbraio M, Demers A, McNicoll N, Pohankova P, Perreault A, Sejlitz T, Escher E, Silverstein RL, Lamontagne D, Ong H

Circulation Research (2002)

Landmark study identifying CD36 as the mediator of Hexarelin's cardioprotective effects in the heart, establishing a GH-independent mechanism distinct from the GHS-R1a pathway.

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Cardioprotective effect of growth hormone-releasing peptides in ischemia-reperfusion injury

Berti F, Muller E, De Gennaro Colonna V, Rossoni G

European Journal of Pharmacology (1998)

Demonstrated that Hexarelin reduced infarct size and preserved cardiac function in animal models of ischemia-reperfusion injury, providing early evidence for its direct cardioprotective effect.

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