Peptide library / Skin & aging / Pentapeptide-18
Pentapeptide-18
A five amino acid peptide resembling an enkephalin, marketed to relax expression lines.
Effects studied or claimed
What it is used or promoted for, and where each effect has actually been seen
- Reduce expression lines, topicalLab
How it is thought to work
It mimics enkephalins and is proposed to reduce release of acetylcholine at the nerve-muscle junction.
What the evidence shows
Mostly manufacturer in vitro and small in vivo data.
Safety and unknowns
Well tolerated in topical products.
Regulatory status
Cosmetic ingredient, not a drug.
Regulatory status changes quickly. This entry was last reviewed on 27 October 2026. Confirm current status with the FDA before relying on it.
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General information, not medical advice. Do not buy or inject unregulated peptides.