Retatrutide vs PEG-MGF
Side-by-side comparison of key properties, dosing, and research.
GLP-1 / Weight Loss Agonists
RetatrutideAnabolic & IGF
PEG-MGF- Summary
- Retatrutide is an investigational triple receptor agonist targeting GLP-1, GIP, and glucagon receptors simultaneously. Phase 2 trials showed an unprecedented average 24% body weight reduction at 48 weeks — exceeding any approved medication to date. It is in Phase 3 trials as of 2024.
- PEG-MGF (Pegylated Mechano Growth Factor) is a modified form of MGF (Mechano Growth Factor) where polyethylene glycol (PEG) chains have been attached to extend its half-life from minutes to days. Native MGF is released locally in muscle in response to mechanical stress and quickly degrades. PEGylation allows systemic administration with sustained circulation, enabling whole-body muscle repair and anabolic signaling rather than the purely local effect of native MGF.
- Half-Life
- ~10–12 days
- ~3 days (due to PEGylation)
- Admin Route
- SubQ
- SubQ
- Research
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- —
- Typical Dose
- 0.5 mg → 1 mg → 2 mg → 4 mg → 8 mg → 12 mg
- 200–400 mcg
- Frequency
- Once weekly
- 2–3x per week
- Key Benefits
- ~24% body weight reduction at 48 weeks in Phase 2 (highest dose)
- Superior to both semaglutide and tirzepatide in early trial comparisons
- Triple receptor mechanism addresses multiple obesity pathways
- Significant reduction in liver fat (MASH/NAFLD indication being studied)
- Improved cardiovascular and metabolic markers
- Once-weekly dosing
- Potential for greatest weight loss of any currently investigated compound
- Extended half-life (~3 days) vs native MGF (minutes)
- Systemic muscle satellite cell activation via subcutaneous injection
- Promotes muscle fiber repair and hypertrophy throughout the body
- Enhanced recovery from intense training or muscle injury
- Synergistic with IGF-1 LR3 and growth hormone peptides
- Useful in sarcopenia, post-injury recovery, and athletic performance
- Single injection provides multi-day anabolic signaling
- Side Effects
- Nausea and vomiting (common during titration, similar to semaglutide/tirzepatide)
- Diarrhea
- Constipation
- Heart rate increase (from glucagon receptor agonism)
- +2 more
- Water retention and localized swelling
- Potential hypoglycemia at high doses
- Theoretical cancer growth risk (growth factor)
- Injection site reactions
- +1 more
- Stacks With
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