Quick summary
Leuphasyl (Pentapeptide-18) is a synthetic enkephalin analog that modulates calcium channels at neuromuscular junctions to relax expression wrinkles. It acts upstream of botulinum toxin without a frozen appearance and pairs with Argireline for synergy.
Overview
Leuphasyl is a synthetic pentapeptide (Tyr-D-Ala-Gly-Phe-Leu) developed by Lipotec as a cosmeceutical anti-wrinkle active. Classified under the INCI name Pentapeptide-18, it is an enkephalin analog that modulates calcium channel activity in nerve terminals. It is widely used in prestige anti-aging serums and eye creams, frequently combined with Argireline (Acetyl Hexapeptide-3) for synergistic wrinkle-relaxing effects without injection.
Mechanism of action
Leuphasyl mimics endogenous enkephalins by binding to opioid receptors on the presynaptic membrane of neuromuscular junctions. Receptor binding triggers a conformational change that initiates an intracellular cascade reducing nerve cell excitability. This dampens the calcium-dependent vesicular release of acetylcholine at the neuromuscular junction, attenuating the intensity of facial muscle contractions that produce expression lines. Unlike botulinum toxin, Leuphasyl acts upstream at the receptor level rather than by cleaving SNARE proteins, preserving partial muscle motility and avoiding the frozen appearance associated with injections. When formulated alongside Argireline, which operates via a distinct SNARE-complex interference pathway, the two peptides produce additive wrinkle reduction exceeding either ingredient alone.
Dosing protocols
| Purpose | Route | Dosage | Frequency | Notes |
|---|---|---|---|---|
| anti-wrinkle topical application | topical | 1–5 % | twice daily | Applied in finished formulation at 1–5% concentration. Manufacturer recommends combining with Argireline at equal concentration for enhanced effect. |
Dosing information is for educational purposes only. Consult a qualified healthcare professional before using any peptide.
Research summary
In vitro studies published in Cosmetics (MDPI, 2014) confirm receptor-mediated modulation of Ca2+ channels consistent with enkephalin activity. Clinical split-face studies supplied by the manufacturer demonstrate statistically significant reductions in crow's-foot wrinkle depth after 28 days of twice-daily topical application versus vehicle control. The MDPI study concluded Leuphasyl is safe with no adverse effects and preserves facial expressivity unlike botulinum toxin. No independent peer-reviewed clinical trials exist as of 2026; evidence base is primarily manufacturer-sponsored.[1][2][3]
Evidence grading
Each claimed benefit is graded by the strength of available evidence. Grades reflect study quality, not effect size.
Strong = multiple RCTs · Moderate = limited trials or observational · Preliminary = animal or in vitro only · Insufficient = anecdotal or no published data
Side effects
Side effects vary by individual. This is not an exhaustive list. Report unusual symptoms to a healthcare professional.
Common stacks
Peptides commonly paired with Leuphasyl for synergistic effects.
Legal status
Sold as a cosmetic active ingredient worldwide. No regulatory restrictions apply in the US, EU, or most jurisdictions. Available OTC in serums, creams, and eye products. Not classified as a drug.
Sourcing & access
Research compound
Leuphasyl is classified as a research compound. Regulatory status varies by jurisdiction. Always verify current legal status and source from vendors providing third-party certificates of analysis (COA).
Frequently asked questions
Leuphasyl is a synthetic pentapeptide with the sequence Tyr-D-Ala-Gly-Phe-Leu, developed by Lipotec and classified as Pentapeptide-18 under INCI. It is a cosmetic anti-wrinkle active that mimics endogenous enkephalins, binding presynaptic opioid receptors at neuromuscular junctions to reduce the intensity of facial muscle contractions that produce expression lines.
Leuphasyl binds opioid receptors on presynaptic membranes at neuromuscular junctions, dampening calcium-dependent acetylcholine release and attenuating facial muscle contractions. Unlike botulinum toxin, it acts at the receptor level rather than cleaving SNARE proteins, preserving partial muscle motility.
Leuphasyl is sold as an unregulated cosmetic active ingredient worldwide with no prescription required. Side effects are rare and limited to skin irritation at high concentrations and very rare contact sensitization.
Leuphasyl provides a milder, non-injectable alternative to botulinum toxin for expression wrinkles. Clinical studies show statistically significant wrinkle reduction, but the effect is less dramatic than injectable Botox. It is often combined with Argireline for enhanced results.