GHRP-2 vs MGF
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.
GHRP-2
GHRP-2 is a synthetic hexapeptide that acts as a ghrelin mimetic, stimulating the pituitary gland to secrete growth hormone (GH). It is one of the most potent GH secretagogues studied, producing stronger GH pulses than GHRP-6 with comparatively less appetite stimulation.
Full profileMGF
MGF (Mechano Growth Factor) is a splice variant of IGF-1 produced locally in muscle tissue in response to mechanical loading (exercise, especially eccentric loading). Unlike circulating IGF-1 which is produced primarily by the liver, MGF is generated within the muscle itself and acts locally to activate satellite cells (muscle stem cells) — the cells responsible for muscle repair, growth, and adaptation. It is considered the primary local anabolic signal generated by resistance training.
Full profile| GHRP-2 | MGF | |
|---|---|---|
| Category | Performance & Growth Hormone | Performance & Growth Hormone |
| Also known as | Growth Hormone Releasing Peptide-2, Pralmorelin, KP 102 | Mechano Growth Factor, IGF-1Ec, Insulin-like Growth Factor splice variant |
| Evidence | Preclinical only | Preclinical only |
| Dosing range | 100mcg–300mcg mcg, 1–3 times daily, on an empty stomach | 100mcg–300mcg mcg, Post-workout (within 30–60 minutes of training), 3–4x weekly |
| Administration | Subcutaneous injection, Intramuscular injection | Intramuscular injection (into worked muscle — critical for local effect), Subcutaneous injection (produces more systemic distribution) |
| Key side effects | Increased hunger (less than GHRP-6), Elevated cortisol and prolactin at high doses, Water retention, Injection site irritation | Localized muscle swelling at injection site (normal response), Hypoglycemia (less pronounced than IGF-1 DES but present), Very short half-life means side effects are brief, Potential overuse injury if post-workout injection is used consistently without adequate recovery |
| Cited sources | 3 references | 3 references |
Key differences
- Administration: GHRP-2 — Subcutaneous injection, Intramuscular injection; MGF — Intramuscular injection (into worked muscle — critical for local effect), Subcutaneous injection (produces more systemic distribution).
- Frequency: GHRP-2 is typically 1–3 times daily, on an empty stomach; MGF is Post-workout (within 30–60 minutes of training), 3–4x weekly.
How each works
GHRP-2
GHRP-2 has been extensively studied in both animal and human subjects. Clinical trials have demonstrated significant GH elevation in healthy adults, with a peak GH pulse occurring 15–30 minutes post-injection. Studies show it increases IGF-1 levels with chronic use and may have mild cardioprotective properties. Unlike GHRP-6, it has a lower propensity to stimulate cortisol and prolactin at standard doses.
MGF
MGF is encoded by the IGF-1 gene but produced via alternative splicing that generates a unique 49-amino acid C-terminal E-peptide (Ec peptide). The Ec peptide has distinct biological activity from the IGF-1 domain — it directly activates satellite cell proliferation through a receptor pathway separate from the standard IGF-1R. Studies in rodents show that local MGF injection produces significant muscle hypertrophy in the injected limb without systemic IGF-1 elevation. MGF expression spikes within 30 minutes of resistance exercise and declines over 24–48 hours — aligning precisely with the post-exercise anabolic window.
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.