Is ISOLEUCINE safe to use in EU cosmetics?

ISOLEUCINE 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 function does ISOLEUCINE serve in cosmetics?

According to the EU CosIng inventory, ISOLEUCINE carries the following function designation(s): ANTISTATIC, HAIR CONDITIONING, SKIN CONDITIONING.

How do I check if my formula contains ISOLEUCINE?

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 3466215/10/2010

ISOLEUCINE

L-Isoleucine; DL-allo-Isoleucine; 2-Amino-3-methylpentanoic acid

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

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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.

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Chemical identity and properties

PubChem 2D chemical structure for CAS 443-79-8

CAS 443-79-8PubChem CID 791

2-Amino-3-methylpentanoic acid

2-amino-3-methylpentanoic acid is a branched chain amino acid that consists of 3-methylpentanoic acid bearing an amino substituent at position 2. It is a branched-chain amino acid and an alpha-amino acid. — ChEBI

IUPAC name: 2-amino-3-methylpentanoic acid

Molecular formula: C6H13NO2
Molecular weight: 131.17 g/mol
Exact mass: 131.094628657 Da
XLogP3: -1.7
Topological polar surface area: 63.3 Å²
Hydrogen-bond donors: 2
Hydrogen-bond acceptors: 3
Covalent units: 1
Defined stereocentres: 0

Also known as

CHEBI:38264RefChem:463945DL-ISOLEUCINE2-amino-3-methyl-pentanoic acidH-DL-allo-Ile-OHIsoleucine, DL-3107-04-8DL-2-Amino-3-methylpentanoic acid

16 more reported names

Isoleucine, allo-Isoleucine, threo-L-Isoleucine, allo-L-Isoleucine, threo-L(+)-Isoleucine(2S,3S)-Alpha-amino-beta-merthylvalericacidNSC-9958Pentanoic acid, [S-(R*,R*)]-FD3037(dl)-isoleucineIsoleucine #NSC-206282(rac)-IsoleucineNorvaline, threo-AS-49219(2r,3r)-2-amino-3-methyl-pentanoic acid

Open full PubChem record PubChem annotations 3D structure image

External database identifiers

ChEBI:CHEBI:38264
EPA DTXSID:DTXSID80901480
PubMed:22572786
PubMed:22479568
PubMed:22291968
PubMed:22087350
PubMed:21949647
PubMed:21829349
PubMed:21573071
PubMed:21269446
PubMed:21107576
PubMed:20849675
PubMed:20686667
PubMed:20668018

Retrieved from NIH PubChem on 2026-08-31 by checksum-valid CAS matching. Chemical properties do not replace the regulatory decision on this page.

PubChem 2D chemical structure for CAS 73-32-5

CAS 73-32-5PubChem CID 6306

L-Isoleucine

L-isoleucine is the L-enantiomer of isoleucine. It has a role as a mouse metabolite, a Saccharomyces cerevisiae metabolite, a plant metabolite, an Escherichia coli metabolite, a human metabolite and an algal metabolite. It is a L-alpha-amino acid, an aspartate family amino acid, an isoleucine and a proteinogenic amino acid. It is a conjugate base of a L-isoleucinium. It is a conjugate acid of a L-isoleucinate. It is an enantiomer of a D-isoleucine. It is a tautomer of a L-isoleucine zwitterion. — ChEBI

IUPAC name: (2S,3S)-2-amino-3-methylpentanoic acid

Molecular formula: C6H13NO2
Molecular weight: 131.17 g/mol
Exact mass: 131.094628657 Da
XLogP3: -1.7
Topological polar surface area: 63.3 Å²
Hydrogen-bond donors: 2
Hydrogen-bond acceptors: 3
Covalent units: 1
Defined stereocentres: 2

Also known as

Isoleucine2S,3S-Isoleucine(S)-Isoleucine(S,S)-Isoleucine2-Amino-3-methylvaleric aciderythro-L-IsoleucineL-IleIsoleucina

16 more reported names

alpha-Amino-beta-methylvaleric acidNorvaline, 3-methyl-Valeric acid, 2-amino-3-methyl-Isoleucinumiso-leucine(2S,3S)-alpha-Amino-beta-methyl-n-valeric acid(2S,3S)-alpha-Amino-beta-merthylvaleric acid(S-(R*,R*))-2-Amino-3-methylpentanoic acid(2S,3S)-alpha-Amino-beta-merthyl-n-valeric acidNSC-46708FEMA NO. 467504Y7590D77CHEBI:17191[S-(R*,R*)]-2-Amino-3-methylpentanoic acid(2S,3S)-2-amino-3-methylpentanoateL-Isomer Isoleucine

Open full PubChem record PubChem annotations 3D structure image

External database identifiers

ChEBI:CHEBI:17191
ChEMBL:CHEMBL1233584
EPA DTXSID:DTXSID1047441
EPA DTXSID:DTXSID2046882
PubMed:40885242
PubMed:39172838
PubMed:31926187
PubMed:29968805
PubMed:23108620
PubMed:23107499
PubMed:23105881
PubMed:23088461
PubMed:23084640
PubMed:23079773
PubMed:23061283
PubMed:23056478

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 ISOLEUCINE

INCI name

ISOLEUCINE

INN name

isoleucine

Description

L-Isoleucine; DL-allo-Isoleucine; 2-Amino-3-methylpentanoic acid

Record provenance

Inventory reference: 34662
Imported identity: ISOLEUCINE
Source update: 15/10/2010

European Commission CosIng source notes

Annex records for ISOLEUCINE

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Key data

CAS

73-32-5 / 443-79-8

200-798-2 / 207-139-8

Restriction

—

Function

ANTISTATIC: Preventing and/or reducing static electricity by neutralising electrical charge on surfaces.
HAIR CONDITIONING: Enhancing the appearance and feel of hair. Leaving the hair easy to comb, supple, soft and shiny and/or imparting volume, lightness, gloss, texture, etc.
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.

#13778 · ISOLEUCINE

Ingredients with overlapping formulation functions

ISOBUTYL PHENYLHYDRAZINOYL METHANESULFONAMIDEANTISTATIC, UV ABSORBER

ISOBUTYLATED LANOLIN OILANTISTATIC, HAIR CONDITIONING, SKIN CONDITIONING, SKIN CONDITIONING - EMOLLIENT

ISODECYL ISONONANOATEANTISTATIC, SKIN CONDITIONING, SKIN CONDITIONING - EMOLLIENT

ISODECYL SALICYLATEANTISTATIC, SKIN CONDITIONING

ISONONAMIDOPROPYL ETHYLDIMONIUM ETHOSULFATEANTISTATIC

ISONONYL ISONONANOATEANTISTATIC, SKIN CONDITIONING, SKIN CONDITIONING - EMOLLIENT

ISOPROPYL ESTER OF PVM/MA COPOLYMERANTISTATIC, BINDING, EMULSION STABILISING, FILM FORMING, HAIR FIXING

ISOPROPYL LANOLATEANTISTATIC, BINDING, SKIN CONDITIONING, SKIN CONDITIONING - EMOLLIENT, SURFACTANT - EMULSIFYING

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 ISOLEUCINE appears in the CosIng inventory

The CosIng inventory lists ISOLEUCINE 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.

ISOLEUCINE is also tagged with 3 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

ISOLEUCINE 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, ISOLEUCINE carries the following function designation(s):

CAS 73-32-5 / 443-79-8 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.

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

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Source note for ISOLEUCINE

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

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Tools & next steps

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