Pentapeptide-18
Evidence Grade E — Very limited evidence. 1 published studies. 0 registered clinical trials.
Leuphasyl is a cosmetic peptide ingredient designed to reduce expression lines by mimicking natural pain-signalling peptides (enkephalins) to decrease nerve activity at the skin surface. It is used primarily in combination with Argireline. At 570 Da, it is the closest cosmetic peptide to the skin penetration threshold, potentially offering better absorption than larger competitors. It has no pharmaceutical approval.
Leuphasyl has no pharmaceutical authorisation. It is used as a cosmetic ingredient. Industry-sponsored studies report wrinkle reduction of approximately 11–12% when used alone, with potentially greater effects when combined with Argireline (#133).
The evidence base consists of small, primarily industry-sponsored cosmetic studies. As a cosmetic peptide with a proposed mechanism of action at nerve endings beneath the skin surface, the same penetration questions that apply to Argireline are relevant. It is a topical cosmetic ingredient.
Research suggests Leuphasyl mimics enkephalin neuropeptides and may interact with opioid receptors on nerve endings in the skin. The proposed result is reduced acetylcholine release and decreased muscle contraction. These proposed mechanisms are based on the compound's structural similarity to enkephalin rather than on demonstrated topical activity in human skin.
Research suggests industry-sponsored studies report approximately 11-12% wrinkle reduction when used alone, with potentially greater effects in combination with Argireline. One independent study provides additional support. No large double-blind randomised controlled trials exist. The evidence base is small but slightly broader than most cosmetic peptides due to the independent study. The same skin penetration questions that apply to all cosmetic peptides are relevant, though Leuphasyl's smaller size may partly mitigate this concern.
No trials registered on ClinicalTrials.gov for this compound.
The information on this page is provided for educational and research reference purposes only. This is not medical advice. Always consult a qualified healthcare professional before making any health-related decisions.
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