Tetrapeptide-21 Goed Peptide Anti-aging Tetrapeptide-21 at a glance Synthetic peptide Composed of glutamic acid, glycine, and lysine Part of a blend known by the trade name SpecPed® SC-Tetra21 Claimed to boost proteins in skin’s extracellular matrix Tetrapeptide-21 description Tetrapeptide-21 is a synthetic peptide made up of the amino acids glutamic acid, glycine, and lysine. The sequence was derived from extra cellular matrix (ECM) proteins. It acts as a signal peptide to fool the skin into thinking it has to repair and regenerate ECM proteins. When combined with butylene glycol, glycerin, and water, it is known by the trade name SpecPed® SC-Tetra21. The manufacturer of SpecPed® SC-Tetra21 claims it helps prevent wrinkles and other signs of aging by boosting proteins in skin’s extracellular matrix. It’s said to also boost skin’s architectural scaffolding as well as its hyaluronic acid content, which should have a visible impact on skin texture and resilience. The recommended usage level for tetrapeptide-21 is between 0.5-5%. Related ingredients: Peptides