Database/Skin Conditioning/Cysteic Acid
100% natural origin · ISO 16128

Is Cysteic Acid natural?

Yes. Oxidation product of the natural amino acid cysteine; the resulting sulfonic acid group is treated as natural-origin.

INCI nameCysteic Acid
CAS498-40-8
FormulaC3H7NO5S · 169.16 Da
FunctionSkin Conditioning
FeedstockMade by oxidising fermentation- or keratin-hydrolysate-derived cysteine, typically…

How we scored it

Cysteine (fermentation amino acid, natural) oxidised to add SO3H; sulfonate group counts natural. 1.0
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

Made by oxidising fermentation- or keratin-hydrolysate-derived cysteine, typically with hydrogen peroxide or performic acid. The oxidant itself leaves no mass beyond the natural-origin sulfonate group formed.

In plain English

A skin-conditioning ingredient made by oxidising the amino acid cysteine. Cysteine itself comes from fermentation or protein hydrolysis, so this stays close to its natural origin.

Structure

2D structure of Cysteic Acid

2-amino-3-sulfopropanoic acid

PubChem CID 25701 ↗

References

  1. 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.
  2. 2Cysteic Acid. PubChem CID 25701. National Center for Biotechnology Information. pubchem.ncbi.nlm.nih.gov ↗
  3. 3CYSTEIC ACID. CosIng — European Commission cosmetic ingredient database. ec.europa.eu/cosing ↗
  4. 4CYSTEIC ACID. CosIng u2014 European Commission database for information on cosmetic substances and ingredients. https://ec.europa.eu/growth/tools-databases/cosing/search?search=CYSTEIC%20ACID