PEG-MGF vs PT-141 (Bremelanotide)
Side-by-side comparison of key properties, dosing, and research.
Anabolic & IGF
PEG-MGFSexual Health & Libido
PT-141 (Bremelanotide)- Summary
- 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.
- PT-141 (Bremelanotide) is a cyclic peptide melanocortin receptor agonist that enhances sexual desire and arousal through central nervous system mechanisms. It is FDA-approved as Vyleesi for premenopausal women with hypoactive sexual desire disorder (HSDD).
- Half-Life
- ~3 days (due to PEGylation)
- 2–3 hours
- Admin Route
- SubQ
- SubQ
- Research
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- —
- Typical Dose
- 200–400 mcg
- 0.5–1.75 mg
- Frequency
- 2–3x per week
- As needed (not daily)
- Key Benefits
- 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
- Enhances sexual desire and libido in both men and women
- Improves arousal through central nervous system activation
- Effective for psychological erectile dysfunction
- Works for female sexual arousal disorder
- May improve sexual satisfaction and intensity
- Fast-acting — effects within 45–60 minutes
- FDA-approved for HSDD in premenopausal women
- Side Effects
- Water retention and localized swelling
- Potential hypoglycemia at high doses
- Theoretical cancer growth risk (growth factor)
- Injection site reactions
- +1 more
- Nausea (most common — 40% of users in clinical trials)
- Facial flushing and warmth
- Transient blood pressure changes (typically increase then normalize)
- Headache
- +2 more
- Stacks With
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