Is CARBOCYSTEINE safe to use in EU cosmetics?

CARBOCYSTEINE is listed in the EU CosIng ingredient inventory with no direct annex restriction records linked at this time. Always verify against the current official CosIng database before formulating.

What other records share CAS 638-23-3?

CAS 638-23-3 may appear across multiple EU annex records. The CAS lookup page shows all Annex II–VI entries sharing this identifier, useful for identifying cross-annex regulatory status of the same chemical substance.

How do I check if my formula contains CARBOCYSTEINE?

Use the INCI Checker to screen a full ingredient list across selected markets, or use the substance market comparison to review this identity across all supported market datasets.

InventoryRef 7481915/10/2010

CARBOCYSTEINE

L-Cysteine, S-(carboxymethyl)-

CARBOCYSTEINE is listed in the EU CosIng inventory, but no direct annex records are linked on this page yet.

INCI Checker Compare all markets Search similar

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.

Markets and their official sources Search every market for this name

Chemical identity and properties

PubChem 2D chemical structure for CAS 638-23-3

CAS 638-23-3PubChem CID 193653

Carbocysteine

S-carboxymethyl-L-cysteine is an L-cysteine thioether that is L-cysteine in which the hydrogen of the thiol group has been replaced by a carboxymethyl group. It has a role as a mucolytic. It is a L-cysteine thioether and a non-proteinogenic L-alpha-amino acid. It is a conjugate acid of a S-carboxylatomethyl-L-cysteine(1-). — ChEBI

IUPAC name: (2R)-2-amino-3-(carboxymethylsulfanyl)propanoic acid

Molecular formula: C5H9NO4S
Molecular weight: 179.20 g/mol
Exact mass: 179.02522894 Da
XLogP3: -3.1
Topological polar surface area: 126.0 Å²
Hydrogen-bond donors: 3
Hydrogen-bond acceptors: 6
Covalent units: 1
Defined stereocentres: 1

Also known as

CarbocisteineS-Carboxymethyl-L-cysteineS-(CARBOXYMETHYL)-L-CYSTEINEcarbocisteinMucodyneRhinathiolTransbronchinLisomucil

16 more reported names

MuciclarMucolaseReomucilMucocisSiroxylMucolexCarbocisteinaCarbocitMucofanMucoprontl-carbocysteinePectoxL-Carbocisteine(R)-S-(Carboxymethyl)cysteineCarbocisteinumMethista

Open full PubChem record PubChem annotations 3D structure image

External database identifiers

ChEBI:CHEBI:16163
ChEMBL:CHEMBL396416
EPA DTXSID:DTXSID30110060
PubMed:24998638
PubMed:24269501
PubMed:24076166
PubMed:23045014
PubMed:22497630
PubMed:22332001
PubMed:21950673
PubMed:21890513
PubMed:21782562
PubMed:21636230
PubMed:21621508
PubMed:21559953

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 CARBOCYSTEINE

INCI name

CARBOCYSTEINE

INN name

carbocysteine

Description

L-Cysteine, S-(carboxymethyl)-

Record provenance

Inventory reference: 74819
Imported identity: CARBOCYSTEINE
Source update: 15/10/2010

European Commission CosIng source notes

Annex records for CARBOCYSTEINE

Browse

Browse EU annexes

Explore Annex II–VI to see which substances are prohibited, restricted or permitted under specific conditions.

Search annex entries

Search the annex database for entries matching CARBOCYSTEINE or related substances.

Key data

CAS

638-23-3

211-327-5

Restriction

—

Function

ANTI-SEBUM: Helping control sebum production.
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.

#5460 · CARBOCYSTEINE

Ingredients with overlapping formulation functions

CAPRYLOYL HEXAPEPTIDE-74 D-METHIONINE AMIDEANTI-SEBUM, ANTIMICROBIAL, ANTIOXIDANT, SKIN CONDITIONING

CAPRYLOYL OCTAPEPTIDE-33 D-METHIONINEANTI-SEBUM, ANTIMICROBIAL, ANTIOXIDANT, SKIN CONDITIONING

CAPRYLOYL SARCOSINEANTI-SEBUM, PRESERVATIVE

CAPRYLOYL TETRAPEPTIDE-60 NORLEUCYL TYROSYL D-METHIONINEANTI-SEBUM, ANTIMICROBIAL, ANTIOXIDANT, SKIN CONDITIONING

CARDIOSPERMUM HALICACABUM SEED EXTRACTANTI-SEBORRHEIC, ANTI-SEBUM, ANTIMICROBIAL, SKIN CONDITIONING

CARTHAMUS TINCTORIUS FLOWER/VITIS VINIFERA FRUIT/(CAMELIA SINENSIS/DIOSPYROS KA…ANTI-SEBUM, ANTIMICROBIAL, ANTIOXIDANT, SKIN CONDITIONING, SKIN PROTECTING

CASSYTHA FILIFORMIS POWDERANTI-SEBUM, ANTIOXIDANT, PRESERVATIVE, SKIN CONDITIONING, SKIN PROTECTING

CENTIPEDA CUNNINGHAMII LEAF/STEM EXTRACTANTI-SEBUM, ANTIOXIDANT, SKIN PROTECTING

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

ECHA CHEM / Information on chemicals PubChem PUG REST EU Safety Gate cosmetic product alerts ECHA CHEM US EPA CompTox Cosmetic Ingredient Review safety assessments FDA Global Substance Registration System ILO/WHO International Chemical Safety Cards Japan NITE-CHRIP NIOSH Pocket Guide to Chemical Hazards OECD eChemPortal

How CARBOCYSTEINE appears in the CosIng inventory

The CosIng inventory lists CARBOCYSTEINE 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.

CARBOCYSTEINE is also tagged with 2 cosmetic functions 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

CARBOCYSTEINE is listed in the EU CosIng ingredient inventory with no direct annex restriction records linked at this time. Absence of an annex link does not guarantee unrestricted use — always verify against the current official CosIng database before formulating.

According to the EU CosIng inventory, CARBOCYSTEINE carries the following function designation(s):

CAS 638-23-3 may appear across multiple EU annex records. Viewing the CAS lookup page shows all Annex II–VI entries sharing this identifier, which is useful for identifying cross-annex regulatory status of the same chemical substance.

View CAS records

Use the INCI Checker to screen a full ingredient list across selected markets, or compare this substance across all supported market datasets.

Open INCI Checker

Source note for CARBOCYSTEINE

This page reproduces the CosIng inventory entry for CARBOCYSTEINE 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 CARBOCYSTEINE and compare linked records, but verify restrictions and legal status against the current official source text and law before making regulatory decisions.

View sources View updates

Tools & next steps

Check your formula

Scan a full INCI list to detect CARBOCYSTEINE and any linked EU annex restrictions or allergen flags.

INCI Checker

Search similar ingredients

Find other inventory ingredients and annex entries related to CARBOCYSTEINE, its identifiers or nearby name variants.