CYSTEIC ACID
L-3-Sulfoalanine
CYSTEIC ACID is listed in the EU CosIng inventory, but no direct annex records are linked on this page yet.
Regulatory evidence by market
No rule for this ingredient has been imported for any of the 13 markets tracked here.
That describes this inventory, not the law. No imported rule is not evidence that an ingredient is permitted: a rule may exist under another name or identifier, or in a dataset not yet imported here.
Chemical identity and properties
DL-Cysteic acid
Cysteic acid is an amino sulfonic acid that is the sulfonic acid analogue of cysteine. It has a role as an animal metabolite. It is an alanine derivative, a cysteine derivative, an amino sulfonic acid, a carboxyalkanesulfonic acid and a non-proteinogenic alpha-amino acid. — ChEBI
- IUPAC name
- 2-amino-3-sulfopropanoic acid
- Molecular formula
- C3H7NO5S
- Molecular weight
- 169.16 g/mol
- Exact mass
- 169.00449350 Da
- XLogP3
- -4.5
- Topological polar surface area
- 126.0 Ų
- Hydrogen-bond donors
- 3
- Hydrogen-bond acceptors
- 6
- Covalent units
- 1
- Defined stereocentres
- 0
Also known as
16 more reported names
External database identifiers
- ChEBI:CHEBI:21260
- ChEMBL:CHEMBL1171434
- EPA DTXSID:DTXSID40862048
- PubMed:23107541
- PubMed:23044173
- PubMed:22864822
- PubMed:22815635
- PubMed:22689630
- PubMed:22685715
- PubMed:22487448
- PubMed:22331997
- PubMed:22264203
- PubMed:22146536
- PubMed:21977904
- PubMed:21953265
Evidence from additional scientific databases
NIH PubChem PUG-View
Attributed physical-property, hazard, environmental and use annotations.
- Physical Description: Solid; [Merck Index] Source: Haz-Map, Information on Hazardous Chemicals and Occupational Diseases
- Physical Description: Solid Source: Human Metabolome Database (HMDB)
- Signal: Warning Source: European Chemicals Agency (ECHA)
- GHS Hazard Statements: H315 (100%): Causes skin irritation [Warning Skin corrosion/irritation]; H319 (100%): Causes serious eye irritation [Warning Serious eye damage/eye irritation]; H335 (100%): May cause respiratory irritation [Warning Specific target organ toxicity, single exposure; Respiratory tract irritation] Source: European Chemicals Agency (ECHA)
- Precautionary Statement Codes: P261, P264, P264+P265, P271, P280, P302+P352, P304+P340, P305+P351+P338, P319, P321, P332+P317, P337+P317, P362+P364, P403+P233, P405, and P501 (click each P-code to see the statement) Source: European Chemicals Agency (ECHA)
- ECHA C&L Notifications Summary: The GHS information provided by 1 company from 1 notification to the ECHA C&L Inventory. Source: European Chemicals Agency (ECHA)
- Sources/Uses: An amino acid with a C-terminal sulfonic acid group which has been isolated from human hair oxidized with permanganate. It occurs normally in the outer part of the sheep's fleece, where the wool is exposed to light and weather. [ChemIDplus] Source: Haz-Map, Information on Hazardous Chemicals and Occupational Diseases
Mapped by: Existing checksum-valid CAS to unique PubChem CID match. Retrieved: 2026-08-31. Open source record
Scientific classifications and hazard annotations provide context and do not replace the market-specific regulatory decision shown above.
Additional source coverage and match status
| Source | Result | Checked |
|---|---|---|
| NIH PubChem PUG-View | Exact match | 2026-08-31 |
A recorded no-match is useful evidence that the source was checked; it is not a claim that the substance does not exist elsewhere.
Retrieved from NIH PubChem on 2026-08-31 by checksum-valid CAS matching. Chemical properties do not replace the regulatory decision on this page.
L-Cysteic acid
L-cysteic acid is the L-enantiomer of cysteic acid. It has a role as an Escherichia coli metabolite and a human metabolite. It is a cysteic acid, an amino sulfonic acid, a non-proteinogenic L-alpha-amino acid, a L-cysteine derivative and a L-alanine derivative. It is a conjugate acid of a L-cysteate(1-). — ChEBI
- IUPAC name
- (2R)-2-amino-3-sulfopropanoic acid
- Molecular formula
- C3H7NO5S
- Molecular weight
- 169.16 g/mol
- Exact mass
- 169.00449350 Da
- XLogP3
- -4.5
- Topological polar surface area
- 126.0 Ų
- Hydrogen-bond donors
- 3
- Hydrogen-bond acceptors
- 6
- Covalent units
- 1
- Defined stereocentres
- 1
Also known as
16 more reported names
External database identifiers
Retrieved from NIH PubChem on 2026-08-31 by checksum-valid CAS matching. Chemical properties do not replace the regulatory decision on this page.
Inventory details for CYSTEIC ACID
INCI name
CYSTEIC ACID
Description
L-3-Sulfoalanine
Record provenance
- Inventory reference
- 55569
- Imported identity
- CYSTEIC ACID
- Source update
- 15/10/2010
Annex records for CYSTEIC ACID
Key data
- SKIN CONDITIONING
- Maintaining the skin in good condition.
Official EU ingredient-name evidence
The ingredient name exactly matches the official 2025 EU glossary of common ingredient names.
Related inventory evidence
Ingredients with overlapping formulation functions
Additional official and scientific sources
11 external databases to check this identity in
Each link searches that source for this identity. What each source is, and its legal weight
How CYSTEIC ACID appears in the CosIng inventory
The CosIng inventory lists CYSTEIC ACID as a cosmetic ingredient and this page links it to 0 annex records. The inventory entry captures names and identifiers, while the annex records show where the substance is prohibited, restricted or positively listed in EU cosmetics law.
CYSTEIC ACID is also tagged with 1 cosmetic function in the official data. Function labels describe intended use, but they do not replace regulatory review of linked annex records before formulation or labelling work.
Frequently asked questions
Source note for CYSTEIC ACID
This page reproduces the CosIng inventory entry for CYSTEIC ACID from public European Commission cosmetic ingredient materials and shows linked identifiers even when no direct annex match is currently attached.
Use this inventory page to research CYSTEIC ACID and compare linked records, but verify restrictions and legal status against the current official source text and law before making regulatory decisions.
Tools & next steps
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