Best peptide for skin: GHK-Cu, Matrixyl, and the evidence behind cosmetic peptides
GHK-Cu is the most-researched skin peptide. Here's what's well-supported, what's marketing, and how injectable and topical compare.
by Editorial team
GHK-Cu: the skin-research workhorse
GHK-Cu (copper tripeptide-1) is the most-studied skin peptide. It's been shown to increase collagen synthesis, improve skin elasticity, and reduce visible signs of aging in multiple controlled studies — most of which used topical application.
The peptide naturally declines with age in human plasma, which is part of why exogenous supplementation became interesting in the first place.
Topical vs injectable
Topical GHK-Cu has the strongest skin-specific evidence: improved firmness, reduced fine lines, faster wound healing. It's also low-risk if formulated properly.
Injectable GHK-Cu produces more systemic effects (anti-inflammatory, gene-expression changes) but the skin-specific evidence base is thinner than the topical literature.
Matrixyl, palmitoyl peptides, and the cosmetic short list
Matrixyl (palmitoyl pentapeptide-4) is a popular topical with reasonable evidence for collagen support. Argireline gets compared to Botox but the evidence is thinner. For most people, sunscreen + retinoid + vitamin C still does more than any peptide topical.