Topical Peptide

A topical peptide is a short amino-acid chain formulated into a serum, cream, or scalp solution and applied to the skin or hair to signal local pathways — collagen synthesis, antioxidant defence, repair, or muscle-contraction modulation — rather than entering systemic circulation. Cosmetic topical peptides fall into four functional classes: signal peptides (e.g. palmitoyl pentapeptide-4), carrier peptides (e.g. GHK-Cu), enzyme-inhibitor peptides, and neurotransmitter-inhibitor peptides (e.g. SNAP-8, Argireline) (Schagen, 2017, PMID: 29104573). Their effectiveness depends on absorption: the stratum corneum excludes most molecules above ~500 Da (Bos & Meinardi, 2000, PMID: 11168751), so smaller peptides such as GHK-Cu (340 Da) penetrate more readily than larger conjugated peptides, which rely on lipid tails or penetration-enhancing vehicles.

Related guides: Topical peptides pillar · Do topical peptides work

Part of the Aevitas Peptide Glossary.