Application: skin care-aging,repair. Palmitoyl pentapeptide-4 / Matrixyl Helps stimulate collagen synthesis and elastin. The action is very similar to retinol without the irritation. Description: Palmitoyl pentapeptide-4 (Pal-Lys-Thr-Thr-Lys-Ser = Pal-KTTKS) contains 5 amino acids linked to a 16-carbon aliphatic chain for improving the penetration of the molecule through the lipid structures of the skin. It is a matricide.Matrikines are messenger peptides …