Skin & cosmetic
Pentapeptide-18
Leuphasyl
Pentapeptide-18 is a topical cosmetic peptide marketed as a needle-free alternative to botulinum toxin for expression lines, usually formulated alongside Acetyl Hexapeptide-3.
Also known as: pentapeptide 18
- Status
- Pentapeptide-18 is used as a cosmetic or over-the-counter ingredient, not as an approved drug.
- Evidence
- Early human data. Only small or early-phase studies in people so far.
- Half-life
- Not applicable — acts locally in skin.
- How it's taken
- Topical, in a leave-on serum or cream
- Mechanism
- Cosmetic / topical
- Pathways
- Neuromuscular Junction
How Pentapeptide-18 works
Pentapeptide-18 is derived from enkephalin and is proposed to act as an enkephalin-like agonist at presynaptic receptors on the motor neuron, reducing the frequency of acetylcholine release and therefore muscle contraction. This is a different point of intervention from Acetyl Hexapeptide-3, which interferes with the SNARE complex during vesicle fusion — the rationale for combining them.
What research has looked at
- It targets a mechanistically distinct step in neuromuscular transmission from Acetyl Hexapeptide-3, which is a coherent basis for the standard combination.
- Manufacturer studies report reductions in wrinkle depth over several weeks of twice-daily application.
- It is entirely non-invasive and well tolerated.
Evidence level: Early human data. Only small or early-phase studies in people so far. These are areas studied or reported, not promised effects.
Reported side effects and risks
- Cosmetic peptide claims are supported largely by manufacturer-funded studies with small numbers and short duration; independent replication is uncommon.
- Skin penetration is the central unresolved question for topical peptides — most are too large and too hydrophilic to cross the stratum corneum efficiently, and formulation determines far more than the peptide itself. A peptide must reach the neuromuscular junction beneath the dermis to work as claimed, which is a far greater barrier than reaching dermal fibroblasts.
- Effects are considerably smaller than botulinum toxin, and comparisons made in marketing are not supported by head-to-head trials.
- Benefits reverse on discontinuation.
- It is a cosmetic ingredient, not a drug, and is not evaluated by the FDA for efficacy.
Sources
- PubMed research on pentapeptide-18 leuphasyl enkephalin wrinkle · NIH · National Library of Medicine
- DrugBank record for pentapeptide-18 · DrugBank
- Active clinical trials for pentapeptide-18 · U.S. National Library of Medicine
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Related compounds
Pentapeptide-18 FAQ
What is Pentapeptide-18?
Pentapeptide-18 is a topical cosmetic peptide marketed as a needle-free alternative to botulinum toxin for expression lines, usually formulated alongside Acetyl Hexapeptide-3.
How does Pentapeptide-18 work?
Pentapeptide-18 is derived from enkephalin and is proposed to act as an enkephalin-like agonist at presynaptic receptors on the motor neuron, reducing the frequency of acetylcholine release and therefore muscle contraction. This is a different point of intervention from Acetyl Hexapeptide-3, which interferes with the SNARE complex during vesicle fusion — the rationale for combining them.
Is Pentapeptide-18 FDA approved?
No. Pentapeptide-18 is used as a cosmetic or over-the-counter ingredient, not as an approved drug. Evidence level: early human data. Only small or early-phase studies in people so far.
What is the half-life of Pentapeptide-18?
Reported half-life: Not applicable — acts locally in skin.
How is Pentapeptide-18 taken?
Topical, in a leave-on serum or cream.
What side effects have been reported with Pentapeptide-18?
Reported in the sources: Cosmetic peptide claims are supported largely by manufacturer-funded studies with small numbers and short duration; independent replication is uncommon; Skin penetration is the central unresolved question for topical peptides — most are too large and too hydrophilic to cross the stratum corneum efficiently, and formulation determines far more than the peptide itself. A peptide must reach the neuromuscular junction beneath the dermis to work as claimed, which is a far greater barrier than reaching dermal fibroblasts; Effects are considerably smaller than botulinum toxin, and comparisons made in marketing are not supported by head-to-head trials; Benefits reverse on discontinuation; It is a cosmetic ingredient, not a drug, and is not evaluated by the FDA for efficacy.
Educational summary compiled from the sources listed above. Not medical advice. Peptide Vault does not sell, source or recommend any compound. Talk to a qualified clinician before starting or changing anything.