How we scored it
Six residues of natural amino acids (Ala, Leu, Lys, Phe); no acyl or acetyl cap in the INCI name, so no n = 0 mass. Mass fraction 1.00; sequence and termini not given.
What counts. ISO 16128-2 scores the atoms that remain in the final ingredient. Reagents, solvents, catalysts and protecting groups used during manufacture leave no mass behind and are not counted.
Where it comes from
Dominant route is peptide synthesis from fermentation-derived L-amino acids, with protecting groups and coupling agents leaving no mass. No petrochemical fragment is indicated by the INCI name, which has no acetyl or acyl prefix.
In plain English
A short chain of six amino acids, built from alanine, leucine, lysine and phenylalanine, used in skin-care products as a skin-conditioning ingredient. The amino acids are made by fermenting sugars or from protein hydrolysates, then joined by chemical synthesis in a laboratory.
CosIng definition: Hexapeptide-21 is a synthetic peptide consisting of alanine, leucine, lysine and phenylalanine
References
- 1ISO 16128-1:2016 and ISO 16128-2:2017 — Guidelines on technical definitions and criteria for natural and organic cosmetic ingredients and products. ISO, Geneva.
- 2HEXAPEPTIDE-21. CosIng — European Commission cosmetic ingredient database. ec.europa.eu/cosing ↗
- 3HEXAPEPTIDE-21. CosIng u2014 European Commission database for information on cosmetic substances and ingredients. https://ec.europa.eu/growth/tools-databases/cosing/search?search=HEXAPEPTIDE-21