Pentapeptide-18 vs Melanotan II
Side-by-side comparison of key properties, dosing, and research.
Skin & CosmeticAnti-Aging & Longevity
Pentapeptide-18Sexual Health & Libido
Melanotan II- Summary
- Pentapeptide-18 (Leuphasyl) is a synthetic pentapeptide that mimics the sequence of enkephalin, an endogenous neuropeptide. It acts on neuronal pain receptors in facial muscles to reduce muscle contraction intensity and depth of expression lines, functioning similarly to Argireline (Acetyl Hexapeptide-3) but via a different receptor mechanism.
- Melanotan II is a synthetic analog of alpha-melanocyte-stimulating hormone (α-MSH) that stimulates melanin production (skin tanning), suppresses appetite, and enhances sexual function. It is not FDA-approved and has significant safety concerns including mole changes and cardiovascular effects.
- Half-Life
- Not applicable (topical)
- 1–2 hours
- Admin Route
- Topical
- SubQ
- Research
- —
- —
- Typical Dose
- 0.005–0.05% in formulation
- 0.25–0.5 mg
- Frequency
- Twice daily
- Once daily
- Key Benefits
- Reduces depth of expression lines (forehead, crow's feet, glabellar)
- Inhibits acetylcholine release for muscle-relaxing effect
- Complementary mechanism to Argireline for enhanced anti-wrinkle activity
- Reversible and well-tolerated
- No risk of systemic paralysis at cosmetic concentrations
- Suitable for daily use in serums and creams
- Promotes skin tanning and melanin production
- Reduces UV exposure needed to tan
- Enhances libido and sexual function
- May suppress appetite
- Faster, deeper tan development
- Longer-lasting tan maintenance
- Potential photoprotective effects
- Side Effects
- Generally very well-tolerated topically
- Rare skin sensitivity or mild irritation
- Theoretical opioid receptor desensitization with very prolonged high-dose use (not documented cosmetically)
- Nausea (very common, especially in first days)
- Facial flushing
- Spontaneous erections in men
- Darkening or changes in existing moles (monitor closely)
- +3 more
- Stacks With
- —
- —