Ghrelin vs Hexarelin
A neutral, side-by-side comparison of two performance & growth hormone peptides — their mechanisms, dosing ranges, administration routes, side effects, and research evidence. For research and educational purposes only.
Ghrelin
Endogenous 28-amino acid peptide secreted primarily by the stomach that functions as both the primary hunger signal and a potent growth hormone secretagogue. The n-octanoyl modification at Ser-3 (acylated form) is required for GHS-R1a receptor binding and GH-stimulating activity. Understanding ghrelin explains the mechanism behind the entire GHRP class of research peptides.
Full profileHexarelin
Hexarelin is a potent synthetic hexapeptide GHRP (Growth Hormone-Releasing Peptide) that stimulates GH release via the ghrelin receptor. It produces among the highest GH pulses of any GHRP, but also elevates cortisol and prolactin — a trade-off that distinguishes it from more selective options like Ipamorelin.
Full profile| Ghrelin | Hexarelin | |
|---|---|---|
| Category | Performance & Growth Hormone | Performance & Growth Hormone |
| Also known as | GHRL, growth hormone-releasing peptide endogenous, ghrelinergic peptide, acyl ghrelin | Examorelin, EP 23905, MF-6003 |
| Evidence | Investigational (in trials) | Preclinical only |
| Dosing range | 0.5mcg/kg–2mcg/kg mcg/kg, IV or SC bolus; endogenous levels peak pre-meal | 50mcg–200mcg mcg, 1–3x daily (cycling recommended to prevent desensitization) |
| Administration | Intravenous (research), Subcutaneous injection | Subcutaneous injection, Intramuscular injection |
| Key side effects | Appetite stimulation, Transient hyperglycemia, Water retention, GH pulse stimulation | Cortisol elevation, Prolactin elevation, Water retention, Increased appetite |
| Cited sources | 2 references | 1 reference |
Key differences
- Evidence level differs: Ghrelin is investigational (in trials), while Hexarelin is preclinical only.
- Administration: Ghrelin — Intravenous (research), Subcutaneous injection; Hexarelin — Subcutaneous injection, Intramuscular injection.
- Dosing units differ: Ghrelin is dosed in mcg/kg, Hexarelin in mcg — they operate at different scales.
- Frequency: Ghrelin is typically IV or SC bolus; endogenous levels peak pre-meal; Hexarelin is 1–3x daily (cycling recommended to prevent desensitization).
- Research depth: this profile cites 2 sources for Ghrelin vs 1 for Hexarelin.
How each works
Ghrelin
Ghrelin was discovered in 1999 as the endogenous ligand for the GHS-R1a receptor. Its acylated form activates GH release from the pituitary, stimulates appetite via NPY/AgRP hypothalamic neurons, and modulates energy homeostasis and fat storage. The des-acyl form (majority of circulating ghrelin) lacks GHS-R1a activity but has independent cardiovascular and cellular effects.
Hexarelin
Hexarelin produces dose-dependent GH release significantly greater than GHRP-6 or Ipamorelin. It also has direct cardioprotective effects via CD36 receptor binding, independent of GH — making it unique among GHRPs. Studies show protection from ischemic cardiac injury and myocardial fibrosis reduction in animal models. Desensitization occurs with chronic continuous use.
This comparison aggregates public research and structured profile data for informational purposes only. It is not medical advice and does not recommend either compound for human use. Consult a qualified healthcare provider before considering any peptide.