CJC-1295 / Ipamorelin Stack 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.
CJC-1295 / Ipamorelin Stack
The CJC-1295 (without DAC) and Ipamorelin combination is the most widely researched and community-validated growth hormone secretagogue stack. By pairing a GHRH analog with a selective GHRP, the two peptides act synergistically — producing GH pulses significantly larger than either compound alone, while maintaining a physiological pulse pattern and minimal side effects.
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| CJC-1295 / Ipamorelin Stack | PEG-MGF | |
|---|---|---|
| Category | Performance & Growth Hormone | Performance & Growth Hormone |
| Also known as | CJC-1295 Ipamorelin, Mod GRF 1-29 Ipamorelin, CJC Ipa stack, CJC-1295 without DAC with Ipamorelin, GHRH GHRP combination | PEGylated Mechano Growth Factor, Polyethylene Glycol-MGF, Long-acting MGF |
| Evidence | FDA-approved | Preclinical only |
| Dosing range | 100mcg each–300mcg each mcg, once daily before sleep (or 2–3x daily for more aggressive protocols) | 100mcg–400mcg mcg, 2x weekly (Monday/Thursday or similar split) |
| Administration | Subcutaneous injection (both compounds), Administered together in the same injection | Subcutaneous injection (preferred for systemic distribution), Intramuscular injection |
| Key side effects | Water retention (mild, common), Tingling or numbness in hands/feet (transient), Headache (usually first 1–2 weeks), Fatigue or increased sleepiness (often desired at night dose) | 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 | 2 references | 2 references |
Key differences
- Evidence level differs: CJC-1295 / Ipamorelin Stack is fda-approved, while PEG-MGF is preclinical only.
- Administration: CJC-1295 / Ipamorelin Stack — Subcutaneous injection (both compounds), Administered together in the same injection; PEG-MGF — Subcutaneous injection (preferred for systemic distribution), Intramuscular injection.
- Frequency: CJC-1295 / Ipamorelin Stack is typically once daily before sleep (or 2–3x daily for more aggressive protocols); PEG-MGF is 2x weekly (Monday/Thursday or similar split).
How each works
CJC-1295 / Ipamorelin Stack
CJC-1295 without DAC (Mod GRF 1-29) stimulates GHRH receptors on the pituitary, increasing the amplitude of GH pulses. Ipamorelin independently triggers GH release via the ghrelin receptor (GHS-R1a) with high selectivity — minimal cortisol, prolactin, or aldosterone co-elevation. The combination exploits two separate receptor pathways to produce synergistic GH output. Animal and human studies on each compound individually confirm GH and IGF-1 elevation. The combination is extrapolated from mechanistic research and is the most studied protocol in the peptide research community.
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.