Hexarelin

Overview

Hexarelin (His-D-2MeTrp-Ala-Trp-D-Phe-Lys-NH2) is a synthetic hexapeptide growth hormone secretagogue developed by Mediolanum (Italy) in the 1990s. It is a potent ghrelin-receptor (GHSR-1a) agonist that also binds the CD36 scavenger receptor, giving it a cardioprotective signal distinct from other GHRPs. It is not FDA-approved for any indication and remains a research-only compound; its clinical development for GH deficiency and cardiac indications did not reach approval. A defining feature versus other GHRPs is rapid, pronounced tachyphylaxis with chronic daily dosing.

Mechanism of Action

Hexarelin binds GHSR-1a on pituitary somatotrophs and hypothalamic neurons, driving Gq/PLC/IP3 calcium signaling and pulsatile GH release while suppressing somatostatin tone. Like GHRP-6 and GHRP-2 it is non-selective: it meaningfully raises ACTH, cortisol, and prolactin — generally comparable to or greater than GHRP-2 and substantially more than ipamorelin. Separately from the GH axis, hexarelin binds the CD36 scavenger receptor on cardiomyocytes and microvascular endothelium, producing GHSR-1a-independent cardiovascular effects (coronary vasoactivity and preclinical cardioprotection in ischemia-reperfusion models). With repeated dosing the GH response desensitizes rapidly (tachyphylaxis), with attenuation developing over weeks and partial reversal after a washout.

Research Summary

Ghigo et al. (1994, PMID 8126144, JCEM) characterized hexarelin's GH-releasing activity across IV, SubQ, intranasal, and oral routes in healthy men, establishing it as a potent GH secretagogue. Rahim & Shalet (1998, PMID 10990150, Growth Horm IGF Res) demonstrated that twice-daily SubQ hexarelin in healthy elderly subjects caused ~45% attenuation of the GH AUC over 16 weeks, with partial recovery 4 weeks after discontinuation — the canonical human tachyphylaxis study. Bodart et al. (2002, PMID 11988484, Circulation Research) showed that hexarelin's cardiovascular action in perfused hearts is mediated by CD36 rather than GHSR-1a and is absent in CD36-null animals. Hexarelin has never been FDA-approved; grey-market use for body composition, recovery, or cardiac benefit is not clinically validated.

Vendors selling Hexarelin

Scored vendors carrying Hexarelin, ranked by trust grade. Grades are computed from indexed Certificates of Analysis. Full $/mg pricing is on the comparison page.

Prescribers who offer Hexarelin

13 prescribers in our directory work with Hexarelin, each confirmed from their own website. Peptides like Hexarelin require a prescription from a licensed provider.

Reported Side Effects

• Significant rise in ACTH, cortisol, and prolactin (more than ipamorelin; comparable to or greater than GHRP-2)
• Rapid tachyphylaxis — GH response attenuates with chronic daily dosing
• Increased appetite and hunger (ghrelin-receptor agonism)
• Water retention and transient facial flushing/warmth after injection
• Injection-site reactions (erythema, tingling, numbness)
• Impaired insulin sensitivity and hyperglycemia with sustained GH elevation
• Theoretical IGF-1-mediated concerns with long-term use

Compare Hexarelin with Others

Research References

• Growth hormone-releasing activity of hexarelin, a new synthetic hexapeptide, after intravenous, subcutaneous, intranasal, and oral administration in man (1994)
• Does desensitization to hexarelin occur? (1998)
• CD36 mediates the cardiovascular action of growth hormone-releasing peptides in the heart (2002)

Frequently asked questions

Has Hexarelin been independently lab-tested?

Disclosed Labs has collected 10 Certificates of Analysis (COA) for Hexarelin from 4 independent testing labs. 7 vendors have submitted material for testing. Products average 99.4% tested purity across the corpus. Full testing data is available at https://www.disclosedlabs.com/peptides/hexarelin/testing.

What is the average purity of Hexarelin on the market?

Based on 10 COAs analyzed by Disclosed Labs, Hexarelin products average 99.4% (±0.2%) tested purity. Individual vendor results vary; see per-vendor COA data at https://www.disclosedlabs.com/peptides/hexarelin/coas.

Where can researchers source Hexarelin?

5 vendors with Disclosed Labs trust grades currently list Hexarelin, including Real Peptides, Skye Peptides, Peptide Tech. Compare live prices and lab-verified COAs at https://www.disclosedlabs.com/prices/hexarelin.

Which prescribers offer Hexarelin with a prescription?

13 prescribers in the Disclosed Labs directory work with Hexarelin, each confirmed from their own website. Hexarelin requires a prescription from a licensed provider. Browse them at https://www.disclosedlabs.com/prescribers?peptide=Hexarelin.

How does Hexarelin work?

Hexarelin binds GHSR-1a on pituitary somatotrophs and hypothalamic neurons, driving Gq/PLC/IP3 calcium signaling and pulsatile GH release while suppressing somatostatin tone. Like GHRP-6 and GHRP-2 it is non-selective: it meaningfully raises ACTH, cortisol, and prolactin — generally comparable to or greater than GHRP-2 and substantially more than ipamorelin. Separately from the GH axis, hexarelin binds the CD36 scavenger receptor on cardiomyocytes and microvascular endothelium, producing GHSR-1a-independent cardiovascular effects (coronary vasoactivity and preclinical cardioprotection in ischemia-reperfusion models). With repeated dosing the GH response desensitizes rapidly (tachyphylaxis), with attenuation developing over weeks and partial reversal after a washout.

What does the research say about Hexarelin?

Ghigo et al. (1994, PMID 8126144, JCEM) characterized hexarelin's GH-releasing activity across IV, SubQ, intranasal, and oral routes in healthy men, establishing it as a potent GH secretagogue. Rahim & Shalet (1998, PMID 10990150, Growth Horm IGF Res) demonstrated that twice-daily SubQ hexarelin in healthy elderly subjects caused ~45% attenuation of the GH AUC over 16 weeks, with partial recovery 4 weeks after discontinuation — the canonical human tachyphylaxis study. Bodart et al. (2002, PMID 11988484, Circulation Research) showed that hexarelin's cardiovascular action in perfused hearts is mediated by CD36 rather than GHSR-1a and is absent in CD36-null animals. Hexarelin has never been FDA-approved; grey-market use for body composition, recovery, or cardiac benefit is not clinically validated.