Research Applications
Cardioprotection and Cardiac Repair
Hexarelin's most distinctive research application is cardioprotection. Studies demonstrate reduced infarct size (30-50% reduction), improved post-ischemic ventricular function, reduced cardiac fibrosis, and decreased cardiomyocyte apoptosis. Phase 2 clinical trials in heart failure patients showed improved cardiac output and left ventricular ejection fraction.
Growth Hormone Stimulation
Hexarelin produces the strongest acute GH response among peptide GH secretagogues. Research has utilized it for GH stimulation testing, acute GH axis evaluation, and short-term anabolic applications. Its rapid tachyphylaxis limits chronic GH optimization.
Anti-Atherosclerotic Effects
Through CD36-mediated modulation of macrophage cholesterol efflux and reduced oxidized LDL uptake, hexarelin has been researched for anti-atherosclerotic properties. Preclinical studies show reduced arterial plaque formation and improved endothelial function.
Neuroprotection
Research demonstrates hexarelin crosses the blood-brain barrier and exerts neuroprotective effects through GHS-R1a activation in neural tissue. Studies show reduced neuronal apoptosis, improved outcomes in stroke models, and enhanced hippocampal neurogenesis.
GH Deficiency Diagnosis
Due to its potent and reliable GH-releasing effect, hexarelin has been used as a diagnostic agent in GH stimulation testing. Peak GH responses below defined cutoffs indicate pituitary GH secretory insufficiency.
Mechanism of Action
GHS-R1a Receptor Agonism
Hexarelin binds to GHS-R1a on pituitary somatotroph cells with high affinity, activating Gq/11-coupled PLC signaling. The 2-methyltryptophan substitution at position 2 enhances receptor binding affinity compared to GHRP-6, contributing to hexarelin's superior GH-releasing potency.
CD36 Scavenger Receptor Activation
Uniquely among GH secretagogues, hexarelin binds to the scavenger receptor CD36 on cardiomyocytes, macrophages, and endothelial cells. This interaction is independent of GHS-R1a and mediates hexarelin's cardioprotective effects. CD36 activation in the heart triggers anti-apoptotic signaling, reduces oxidative stress, and inhibits cardiac fibrosis through pathways distinct from GH/IGF-1.
Potent GH Release with Tachyphylaxis
Hexarelin produces the highest peak GH levels among GH secretagogues — up to 50-90 ng/mL acutely. However, chronic administration leads to significant tachyphylaxis (desensitization), with GH responses declining by 50-70% after 4-8 weeks of daily use. This desensitization is more pronounced with hexarelin than other GHRPs and involves GHS-R1a receptor internalization and downregulation.
Cortisol, Prolactin, and ACTH Effects
Hexarelin stimulates ACTH, cortisol, and prolactin release — effects that are dose-dependent and more pronounced than with ipamorelin. These neuroendocrine effects are mediated primarily through pituitary GHS-R1a activation.
Biological Pathways
PLC/IP3/Calcium/PKC Pathway (Pituitary)
GHS-R1a activation drives PLC-mediated IP3 production, calcium release, and PKC activation in somatotrophs. The resulting calcium transient is particularly robust with hexarelin, contributing to its strong acute GH release.
CD36/PPARγ Cardiac Pathway
Hexarelin-CD36 interaction in cardiomyocytes activates PPARγ signaling, which upregulates antioxidant defense genes, suppresses NF-κB-mediated inflammation, and reduces cardiac fibrosis through decreased TGF-β1/Smad3 signaling. This pathway operates independently of GH release.
Akt/eNOS Cardioprotection
Through both GHS-R1a and CD36, hexarelin activates the PI3K/Akt/eNOS pathway in cardiac and endothelial cells. Enhanced nitric oxide production improves coronary vasodilation, reduces endothelial dysfunction, and protects against ischemia/reperfusion injury.
GH/IGF-1 Anabolic Axis
Released GH activates the standard JAK2/STAT5/IGF-1 cascade. The strong acute GH pulses stimulate robust hepatic IGF-1 production, driving protein synthesis, lipolysis, and tissue repair through PI3K/Akt/mTOR and MAPK/ERK signaling.
Dosage Information
Calculation Results
Syringe Fill Level (100u syringe)
Protocols
No protocols featuring this peptide yet.
Browse All ProtocolsStability & Storage
Hexarelin is supplied as a lyophilized white powder. Store at -20°C for long-term stability (18-24 months) or 2-8°C for up to 6 months. Protect from light, heat, and moisture.
Reconstitute with bacteriostatic water. The solution should be clear and colorless. Store reconstituted hexarelin at 2-8°C and use within 21-28 days.
Hexarelin has an in-vivo half-life of approximately 60-70 minutes — significantly longer than GHRP-2 or GHRP-6 — attributed to the 2-methyltryptophan substitution which enhances protease resistance. This longer half-life contributes to both the stronger GH response and the more pronounced tachyphylaxis observed with chronic use.
Side Effects & Precautions
Rapid Desensitization (Tachyphylaxis)
The most significant limitation of hexarelin is rapid desensitization of GH responses with chronic daily use. GH output typically declines by 50-70% after 4-8 weeks. This necessitates cycling protocols (e.g., 4-6 weeks on, 2-4 weeks off) for sustained efficacy.
Cortisol and Prolactin Elevation
Hexarelin produces moderate increases in cortisol (20-40%) and prolactin at GH-stimulating doses. These elevations may be clinically relevant with chronic use and warrant monitoring.
Appetite Stimulation
Moderate hunger stimulation occurs through hypothalamic GHS-R1a activation. The effect is intermediate between GHRP-6 (stronger) and ipamorelin (weaker).
Water Retention
Fluid retention in face and extremities occurs during initial use, attributable to GH-mediated sodium retention. Typically resolves over 2-4 weeks.
Injection Site Reactions
Mild local pain, redness, or swelling at injection sites are common and self-limiting.
Flushing and Warmth
Transient facial flushing and sensation of warmth following injection, lasting 15-30 minutes.
Research Use Only. This information is for educational and research purposes only. Not intended for medical advice or self-medication.
Regulatory Status
Hexarelin (examorelin) is not approved by the FDA or major regulatory authorities for clinical use. It underwent Phase 2 clinical trials in Europe for GH deficiency and cardiac indications but did not advance to Phase 3 approval.
The peptide is classified as an investigational research compound. It has a relatively extensive clinical research history with published Phase 1 and Phase 2 trial data, but remains an unapproved investigational agent.
WADA prohibits hexarelin under category S2 (Peptide Hormones, Growth Factors, Related Substances, and Mimetics) of the prohibited list, banned both in-competition and out-of-competition.
Research Studies
Hexarelin: A Unique Cardiac Active Growth Hormone Secretagogue
Locatelli V, Rossoni G, Schweiger F, et al.
Cardioprotective Effects of Hexarelin Independent of GH Release
Rossoni G, De Gennaro Colonna V, Bernareggi M, et al.
Hexarelin Binding to CD36 as a Scavenger Receptor
Demers A, McNicoll N, Bherer E, et al.
Tachyphylaxis and Desensitization to Hexarelin
Rahim A, O'Neill PA, Shalet SM.
Growth Hormone Secretagogues in the Cardiovascular System
Bisi G, Podio V, Valetto MR, et al.
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