Ghrelin vs Gonadorelin
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 profileGonadorelin
Synthetic form of endogenous gonadotropin-releasing hormone (GnRH) that stimulates LH and FSH release from the anterior pituitary. Used in TRT protocols to maintain testicular function and prevent atrophy during exogenous testosterone administration. Preserves spermatogenesis and endogenous testosterone production capacity.
Full profile| Ghrelin | Gonadorelin | |
|---|---|---|
| Category | Performance & Growth Hormone | Performance & Growth Hormone |
| Also known as | GHRL, growth hormone-releasing peptide endogenous, ghrelinergic peptide, acyl ghrelin | GnRH, gonadotropin-releasing hormone, Factrel, Lutrepulse |
| Evidence | Investigational (in trials) | Research-stage |
| Dosing range | 0.5mcg/kg–2mcg/kg mcg/kg, IV or SC bolus; endogenous levels peak pre-meal | 50mcg–200mcg mcg, 2–3x per week subcutaneous |
| Administration | Intravenous (research), Subcutaneous injection | Subcutaneous injection, Intranasal (pulsatile delivery) |
| Key side effects | Appetite stimulation, Transient hyperglycemia, Water retention, GH pulse stimulation | Injection site reactions, Headache, Nausea, Flushing |
| Cited sources | 2 references | 2 references |
Key differences
- Evidence level differs: Ghrelin is investigational (in trials), while Gonadorelin is research-stage.
- Administration: Ghrelin — Intravenous (research), Subcutaneous injection; Gonadorelin — Subcutaneous injection, Intranasal (pulsatile delivery).
- Dosing units differ: Ghrelin is dosed in mcg/kg, Gonadorelin in mcg — they operate at different scales.
- Frequency: Ghrelin is typically IV or SC bolus; endogenous levels peak pre-meal; Gonadorelin is 2–3x per week subcutaneous.
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.
Gonadorelin
Gonadorelin directly binds GnRH receptors in the anterior pituitary to trigger LH and FSH secretion, which in turn stimulates Leydig cells for testosterone production and maintains spermatogenesis. Used as a TRT adjunct, pulsatile gonadorelin administration mimics natural hypothalamic GnRH to prevent testicular suppression associated with exogenous androgen 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.