Palmitoyl pentapeptide-4 vs Copper tripeptide-1
It is put in anti-wrinkle creams, often under the name Matrixyl, to smooth fine lines. One trial of 93 women showed a small gain, but the maker ran it and no one else has repeated it. A skin-care ingredient sold to firm skin, soften wrinkles and regrow hair. The one controlled human trial, of 13 patients, found no skin benefit.
Palmitoyl pentapeptide-4 has the stronger evidence, grade B (some human evidence) against grade C for Copper tripeptide-1. Neither is FDA approved.
Evidence
BSome human evidence
CAnimal and cell studies
Human studies cited
Animal or cell studies cited
Why the grade
One randomized, double-blind, placebo-controlled split-face trial in 93 women showed a measurable reduction in fine lines and wrinkles over 12 weeks, backed by a 1993 cell study identifying the five-amino-acid sequence as a stimulator of collagen production. The trial was run by the manufacturer and has not been independently replicated, which caps it at B.
For the skin anti-ageing use, the controlled human evidence is a single randomized trial of 13 patients after CO2 laser resurfacing, which found no objective difference in redness or wrinkles. The rest is gene-expression work in cultured cells, animal wound and lung-injury models, and cosmetic-company studies summarized in reviews written by the peptide's discoverer.
FDA
Cosmetic ingredient
Palmitoyl pentapeptide-4 is a cosmetic ingredient, sold under trade names such as Matrixyl. It is not approved by the FDA as a drug for any use; the FDA regulates cosmetics but does not approve their ingredients.
Cosmetic ingredient
Copper tripeptide-1 is a cosmetic ingredient and sits outside FDA drug approval; no copper tripeptide-1 or GHK-Cu product is approved by the FDA as a drug for any use. Injectable GHK-Cu sold online is not approved and is sold as a research chemical.
Sold for
Palmitoyl pentapeptide-4, better known as Matrixyl, is the peptide most anti-wrinkle creams point to when they say peptides work.
Copper tripeptide-1 is marketed in serums as a collagen-building, wound-healing peptide that firms skin, softens wrinkles and regrows hair.
Studies say
A single sponsor-run randomized trial found modest wrinkle improvement versus the same moisturizer without the peptide, which is better evidence than most cosmetic peptides have and still short of independent confirmation.
Cell and animal studies show it switches on repair genes and speeds wound closure, but the one blinded human trial found no measurable skin benefit over the control regimen, so the evidence is C.
Class
Signal (collagen) peptide
Carrier/copper peptide
Route
Topical
Topical