KTTKS is a matrikine that originates from the proteolytic hydrolysis of collagen. This peptide stimulates ECM production and types I and III collagen expression in vitro. A more stable form of KTTKS is pal-KTTKS. known as Matrixyl® or palmitoyl pentapeptide-3. https://parisnaturalfoodes.shop/product-category/serenity-formula/