Acetyl Tetrapeptide-9 Best Peptide Anti-Ageing Acetyl Tetrapeptide-9 description A synthetic peptide created by the acetylation (a chemical reaction that joins a stronger substance with a weaker one) of tetrapeptide-9, which is composed of the amino acids aspartic acid, glutamine, histidine and valine.Acetyl tetrapeptide-9 helps visibly restore skin's natural support, including a specialized protein known as lumican, which helps keep skin smooth and taut. Related ingredients: Peptides