FAQ · Cosmetic peptides

What does INCI position mean for cosmetic peptides?

INCI (International Nomenclature of Cosmetic Ingredients) is the standardised ingredient list on every cosmetic product. Ingredients are listed in descending order of concentration above 1 percent; ingredients below 1 percent can be listed in any order at the end. A peptide in the top 8 INCI ingredients is at meaningful concentration. A peptide in the bottom third of the ingredient list is at trace levels (typically below 0.1 percent). Concentration position is the single strongest signal of whether a peptide product is likely to do what the marketing claims.

How INCI ordering works

• · UK Cosmetics Regulation 2013 requires every cosmetic product to list ingredients using INCI names.
• · Ingredients present at 1 percent or higher must be listed in descending order of concentration.
• · Ingredients below 1 percent can be listed in any order at the end.
• · Colourants and fragrance compounds have specific listing rules.

Practical INCI signals

• · Position 1 to 4: usually water, glycerin, base solvents, primary emulsifiers. Not the active.
• · Position 5 to 8: primary active concentration range for a serum. A peptide here is at meaningful concentration.
• · Position 9 to 12: secondary actives, supporting ingredients, preservatives. A peptide here may still be effective if it works at low concentration (some peptides do).
• · Bottom third: below 1 percent unordered. Trace levels. Marketing "contains" claims hide behind this position.

Common INCI names for cosmetic peptides

• · GHK-Cu: "Copper Tripeptide-1".
• · Matrixyl 3000 (Sederma): "Palmitoyl Tripeptide-1" plus "Palmitoyl Tetrapeptide-7".
• · Argireline: "Acetyl Hexapeptide-8".
• · SNAP-8: "Acetyl Octapeptide-3".
• · Vialox: "Pentapeptide-3".

Related: How we rank cosmetic peptide products · Cosmetic peptide hub.