Pentapeptide-18 (Leuphasyl): The Complete Research Guide
Pentapeptide-18, sold under the trade name Leuphasyl, is a synthetic five-amino-acid cosmetic peptide designed to mimic the activity of endogenous enkephalins at the neuromuscular junction, partially reducing the muscle contraction signals that deepen expression wrinkles over time. It is used exclusively as a topical ingredient in serums and eye creams and is best supported by data as a combination ingredient alongside Argireline, where a 28-day manufacturer application study documented roughly double the wrinkle reduction compared to either peptide alone. This guide covers what Pentapeptide-18 does, how it works, the clinical evidence behind it, application protocols, safety considerations, combination use, and its regulatory status.
