GHRP-2 vs PEG-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 profilePEG-MGF
PEG-MGF is Mechano Growth Factor (MGF) conjugated to a polyethylene glycol (PEG) polymer chain. The PEGylation dramatically extends the half-life from ~5 minutes (native MGF) to approximately 24–72 hours, allowing less frequent dosing and systemic distribution rather than purely local action. This trade-off — longer duration vs localized intensity — makes PEG-MGF a different tool than native MGF, better suited for systemic muscle recovery support and convenience-focused protocols.
Full profile| GHRP-2 | PEG-MGF | |
|---|---|---|
| Category | Performance & Growth Hormone | Performance & Growth Hormone |
| Also known as | Growth Hormone Releasing Peptide-2, Pralmorelin, KP 102 | PEGylated Mechano Growth Factor, Polyethylene Glycol-MGF, Long-acting MGF |
| Evidence | Preclinical only | Preclinical only |
| Dosing range | 100mcg–300mcg mcg, 1–3 times daily, on an empty stomach | 100mcg–400mcg mcg, 2x weekly (Monday/Thursday or similar split) |
| Administration | Subcutaneous injection, Intramuscular injection | Subcutaneous injection (preferred for systemic distribution), Intramuscular injection |
| Key side effects | Increased hunger (less than GHRP-6), Elevated cortisol and prolactin at high doses, Water retention, Injection site irritation | Hypoglycemia (less pronounced than IGF-1 DES, more than native MGF due to systemic distribution), Generalized fatigue on injection days, PEG accumulation concern with very high doses over long periods (theoretical — not established at research doses), Localized injection site swelling |
| Cited sources | 3 references | 2 references |
Key differences
- Administration: GHRP-2 — Subcutaneous injection, Intramuscular injection; PEG-MGF — Subcutaneous injection (preferred for systemic distribution), Intramuscular injection.
- Frequency: GHRP-2 is typically 1–3 times daily, on an empty stomach; PEG-MGF is 2x weekly (Monday/Thursday or similar split).
- Research depth: this profile cites 3 sources for GHRP-2 vs 2 for PEG-MGF.
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.
PEG-MGF
PEGylation is a validated pharmaceutical strategy for extending peptide half-life (used in Pegasys/interferon, Somavert/pegvisomant, and others). The PEG chain shields the MGF peptide from proteolytic degradation and slows renal clearance. Research in rodent models confirms PEG-MGF preserves the biological activity of native MGF (satellite cell activation, muscle repair) with extended duration. Unlike native MGF which requires precise post-workout injection timing, PEG-MGF can be injected on a scheduled basis and still achieves systemic muscle-wide satellite cell effects.
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.