Hexarelin
Hexarelin is one of the most potent synthetic growth hormone releasing peptides (GHRPs). It stimulates GH release through ghrelin receptor activation and has notable cardiac and anti-fibrotic research applications in addition to its GH-axis effects.
Common Dosage
100mcg - 200mcg 2-3x daily (subcutaneous)
Category
Growth Hormone
- Potent GH release
- Cardiac tissue protection
- Muscle preservation
- Anti-fibrotic effects
- Increased IGF-1
Hexarelin (Examorelin) is a synthetic hexapeptide developed in the early 1990s by researchers at Europeptides in France as part of a broader effort to identify potent, selective growth hormone secretagogues. It belongs to the GHRP (Growth Hormone Releasing Peptide) family alongside GHRP-2, GHRP-6, and Ipamorelin, but is generally regarded as the most potent of this class in terms of raw GH pulse amplitude. Originally studied as a potential treatment for GH deficiency, hexarelin gained additional research attention in the late 1990s when researchers discovered it possessed direct cardiac effects independent of its GH-releasing action — an unexpected finding that opened a separate line of cardiovascular investigation.
Hexarelin acts as a ghrelin receptor (GHS-R1a) agonist, triggering a powerful pulse of GH secretion from the anterior pituitary. Unlike ipamorelin, hexarelin also activates CD36 scavenger receptors on cardiac tissue — a completely separate mechanism responsible for its direct cardioprotective effects. This dual-receptor activity means hexarelin has two distinct pharmacological profiles: a GH secretagogue for metabolic and anabolic effects, and a CD36 ligand for cardiac and anti-fibrotic effects. The cardiac action appears to be independent of GH levels and IGF-1 changes, which is why its cardiovascular research applications are studied separately from its endocrine effects.
- GH deficiency evaluation — hexarelin stimulation tests have been used diagnostically to assess pituitary GH reserve
- Cardiac protection and recovery following ischemic injury — CD36 receptor activation reduces infarct size in animal models
- Anti-fibrotic effects in cardiac and skeletal muscle tissue
- Muscle preservation in GH-deficient states and sarcopenia research
- Post-surgical recovery support through enhanced IGF-1 production
- Comparison studies against GHRP-2 and GHRP-6 for GH pulse optimization
Cardiac Ischemia Research
A series of rodent studies demonstrated that hexarelin administered prior to and following cardiac ischemia-reperfusion significantly reduced infarct size and preserved contractile function. The effect was replicated in CD36-knockout mice only partially, confirming that both GH-dependent and CD36-dependent pathways contribute to cardiac protection.
GH Pulse Comparison
Head-to-head studies against GHRP-2 and GHRP-6 consistently show hexarelin produces the largest GH pulse of the three at equivalent doses. However, this potency also comes with greater cortisol and prolactin co-secretion, and more rapid desensitization with daily use — making cycling strategies important.
Anti-fibrotic Muscle Effects
Research in aged animal models showed hexarelin administration reduced collagen deposition in skeletal and cardiac muscle — effects attributed to CD36 signaling pathway modulation. This finding has implications for conditions involving excessive fibrosis, including cardiomyopathy and Duchenne muscular dystrophy research models.
- Cortisol and prolactin co-secretion — more pronounced than ipamorelin or GHRP-2; relevant for daily or long-term protocols
- Desensitization with continuous daily use — pulsatile or cycling dosing strategies are required to maintain GH response
- Water retention and bloating, particularly at higher doses
- No completed human clinical trials for anabolic or recovery applications — all data from animal models or small observational reports
- Not FDA-approved; not validated for human therapeutic use outside diagnostic GH testing
- Prolactin elevation may affect libido and cause galactorrhea at sustained high doses
- Cortisol elevation
- Prolactin elevation
- Water retention
- Increased appetite
- Desensitization with long-term daily use