Pentapeptide-18 vs Leuprolide
Side-by-side comparison of key properties, dosing, and research.
Skin & CosmeticAnti-Aging & Longevity
Pentapeptide-18Sexual Health & Libido
Leuprolide- 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.
- Leuprolide is a synthetic GnRH superagonist that, with continuous administration, paradoxically suppresses LH and FSH through receptor desensitization — the opposite effect of pulsatile GnRH. Used medically for prostate cancer, endometriosis, and precocious puberty. In men's health, short-duration use for PCT and testosterone suppression rebound.
- Half-Life
- Not applicable (topical)
- ~3 hours (SC/IM), but depot formulations last 1–12 months
- Admin Route
- Topical
- SubQ, IM
- Research
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- Typical Dose
- 0.005–0.05% in formulation
- 7.5 mg monthly, 22.5 mg 3-monthly, or 45 mg 6-monthly
- Frequency
- Twice daily
- Per depot schedule
- 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
- Medical: reduces testosterone in prostate cancer
- Medical: suppresses estrogen in endometriosis and uterine fibroids
- Medical: delays precocious puberty
- Research: testosterone rebound effect after short course
- Transgender care: hormone suppression in adolescents
- Research: hormonal re-sensitization protocols
- 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)
- Hot flashes (with testosterone suppression)
- Decreased libido and erectile dysfunction
- Initial testosterone flare (first 1–2 weeks)
- Bone density loss with long-term use
- +3 more
- Stacks With
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