Potent synthetic hexapeptide GH secretagogue — among the most potent GHS-R1a agonists. Studied for cardiac repair beyond GH axis effects via direct CD36 receptor activity. Orphan drug potential for growth hormone deficiency.
30–45 minutes; pulsatile dosing required to avoid desensitization
SKUs
2
Evidence
Moderate Evidence
Hexarelin is a synthetic hexapeptide and one of the most potent growth hormone releasing peptides (GHRPs) developed. It activates the ghrelin receptor to stimulate strong GH pulses and has also been studied for direct cardiac protective effects independent of GH. It is not FDA-approved and is used primarily as a research tool.
Growth Hormone Research
Hexarelin produces among the most potent GH responses of the GHRP compounds. Research has used it to study GH axis dynamics, pituitary reserve, and the effects of strong GH stimulation on body composition and IGF-1 levels.
Cardiovascular Research
Notably, hexarelin has been studied for cardiac effects that appear to be independent of its GH-stimulating activity. Research in animal models of heart failure showed protective effects on cardiac function, attributed to direct ghrelin receptor activation in cardiac tissue. Human cardiac studies are limited.
GH Axis Desensitization
An important research finding with hexarelin is that it produces rapid desensitization with repeated daily use — the pituitary becomes less responsive and GH responses diminish. This is different from compounds like ipamorelin and makes intermittent use patterns more relevant for research applications.
Very potent GH stimulation compared to other GHRP compounds.
Cardiac protective effects in animal heart failure models, likely via direct receptor activation.
Documented desensitization with frequent repeated dosing in research subjects.
Not FDA-approved; no pharmaceutical development resulted in an approved product.
The rapid desensitization with daily use is an important practical limitation compared to other GH secretagogues. The cardiac research is primarily preclinical and has not been confirmed in large human trials. Like other GHRPs, it also stimulates cortisol and prolactin. Its potency means dosing precision matters more than with weaker compounds.
Hexarelin activates the ghrelin receptor in the pituitary gland, which triggers a burst of GH release. Compared to earlier GHRP compounds, hexarelin produces a larger GH pulse for the same dose. Interestingly, the same receptor also exists in heart muscle cells. When hexarelin activates these cardiac ghrelin receptors, it triggers cell survival and protective signaling in the heart independently of any GH that gets released. This dual action — pituitary GH stimulation and direct cardiac receptor activation — makes hexarelin somewhat unique among the GHRP family. The desensitization that occurs with daily use is thought to result from receptor downregulation in the pituitary, which recovers with a break from dosing.
Not FDA-approved. Cortisol and prolactin are stimulated alongside GH. The cardiac research suggests direct cardiac receptor activity, which could have unknown implications with repeated use in people with cardiac conditions. The rapid pituitary desensitization with daily use affects research protocols significantly. Standard GH-related safety considerations apply.
Moderate Evidence
This compound has been studied in Phase 1 or Phase 2 human trials. Evidence is encouraging but more large-scale trials are needed.
Published Research Ranges
1–2mcg/kg per injection; 200mcg maximum typical dose in research; cycling recommended
Research Context Only: These are ranges reported in published scientific studies for educational reference. They are not dosing recommendations. This is not medical advice. Always consult a qualified healthcare professional.
Sources listed here are from the platform research library. All links open the original publication. No citations are generated by AI.
Hexarelin, a GH-Releasing Peptide, and Cardioprotection: Receptor Involvement
Cardiovascular Research • 2005
• DOI: 10.1016/j.cardiores.2005.06.025
Growth Hormone Response to L-Arginine Alone and Combined with Different Doses of Growth Hormone-Releasing Hormone: A Systematic Review and Meta-Analysis
Growth Hormone-Releasing Peptide-6 (GHRP-6) Ameliorates Post-Infarct Ventricular Remodeling and Systolic Dysfunction in a Model of Permanent Coronary Ligation
Pharmacological targeting of the hyper-inflammatory response to SARS-CoV-2-infected K18-hACE2 mice using a cluster of differentiation 36 receptor modulator
Research Education Only: This profile is for educational purposes only. All information is sourced from published scientific literature. This is not medical advice. Not for human consumption. Consult qualified medical professionals for any health decisions.
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