Is L-Methionine safe in cosmetics?
L-Methionine has a safety rating of "GOOD" in our database. EU status: permitted. US status: permitted.
Good
Cosmetic Ingredient
L-Methionine
Also known as: 2-Amino-4-methylthiobutanoic acid (S)-, 2-Amino-4-(methylthio)butyric acid, (S)-, EINECS 200-562-9, Methioninum, UNII-AE28F7PNPL (+15 more)
INCI: METHIONINE
L-Methionine (CAS 63-68-3) is a cosmetic cosmetic ingredient functioning as Antistatic, Hair Conditioning, Skin Conditioning, Antioxidant. NOAEL 1474 mg/kg bw/day (cross-referenced against ToxValDB ECHA IUCLID); EU Regulation 1223/2009 status: permitted. Industrial safety data is also available in the chemical safety database. Same-CAS public records also appear in industrial chemical safety and pharmaceutical data.
View industrial chemical safety profile for CAS 63-68-3 →
Auto-generated CPSR Part A draft with source citations
Function
Antistatic, Hair Conditioning, Skin Conditioning, Antioxidant
Safety Rating
GOOD
Chemistry & Identifiers
IUPAC Name
(2S)-2-amino-4-methylsulfanylbutanoic acid
InChIKey
FFEARJCKVFRZRR-BYPYZUCNSA-N
Regulatory Status
EU EU Status
permitted
US US Status
permitted
US Notes
GRAS as racemic DL-mixture per 21 CFR 172.320; no cosmetic restrictions
For full compliance data across multiple jurisdictions, use the Substance Compliance tool.
Safety Data
Margin of Safety, dermal absorption, and sensitization profile summaries for L-Methionine.
Calculate MoS for your specific formulation with the MoS Calculator.
Pre-Calculated Safety Assessment
Pre-calculated NOAEL → SED → MoS audit trail for L-Methionine across SCCS product categories, with measured dermal absorption where available.
EPA ToxValDB — Toxicity Values
6 toxicity values from EPA ToxValDB (aggregated from CCTE, HPV, ToxRefDB, IRIS, and other regulatory dossiers).
| Endpoint | Value | Species | Route | Duration | Source |
|---|---|---|---|---|---|
| LC50 | >5250 mg/m3 | Rat | inhalation | - | ECHA IUCLID |
| LD50 | >10000 mg/kg | Rat | oral | - | ECHA IUCLID |
| LD50 | >10000 mg/kg | Mouse | oral | - | ECHA IUCLID |
| LD50 | =4328 mg/kg | Rat | injection | - | ECHA IUCLID |
| LEL | >6600 mg/kg-day | Rat | oral | - | ECHA IUCLID |
| LD50 | =36000 mg/kg | Rat | oral | - | ChemIDplus |
ECHA REACH Registration
European Chemicals Agency REACH dossier and Substances of Very High Concern listing.
Registration Type
Full
Tonnage Band
10 - 100 tonnes
Substance Type
SUBSTANCE
SVHC Candidate
No
Additional Ingredient Properties
5 property records from structured ingredient metadata.
acne
{"cas_number": "63-68-3", "anti_acne_mechanism": "anti_inflammatory", "comedogenicity_rating_0_to_5": "0", "acne_type_efficacy": "inflammatory", "sebum_reduction_pct_clinical": "0-5", "prescription_required_usa": "No", "otc_drug_monograph_category": "No", "max_otc_concentration_pct": "No limit", "japan_quasi_drug_anti_acne": "No", "korea_functional_cosmetic_acne": "No", "eu_cosmetic_restriction_ac…
anti_aging
{"anti_aging_claim": "antioxidant-protection", "mechanism_of_action": "Building block for proteins, NMF component", "target_skin_layer": "epidermis", "collagen_stimulation": "Mild", "elastin_protection": "Mild", "wrinkle_reduction_pct": "5-10", "clinical_study_duration_weeks": "8", "sample_size": "25", "double_blind": "No", "placebo_controlled": "Yes", "published_journal": "Int J Cosmet Sci", "imp…
hair_care
{"hair_function": "strengthening", "hair_type_suitability": "all", "curl_pattern_suitability": "all", "porosity_suitability": "high", "protein_sensitivity": "protein", "moisture_protein_balance": "yes", "cg_method_approved": "not-a-silicone", "silicone_type": "not-a-sulfate", "sulfate_type": "no", "drying_alcohol": "no", "fatty_alcohol": "no", "heat_protectant": "yes", "color_safe": "strengthens",…
pregnancy_detail
{"pregnancy_safe": "yes", "breastfeeding_safe": "yes", "risk_category": "not-rated", "reason": "Safe; amino acid", "source": "dermatology literature"}
uv_stability
{"uv_stable": "yes", "uv_degradation_rate": "stable", "photosensitizer": "no", "phototoxic": "no", "photoallergic": "no", "requires_uv_protection_packaging": "no", "color_change_uv": "no", "odor_change_uv": "no", "efficacy_loss_uv_pct": "0", "spf_contribution": "no", "uva_protection": "no", "uvb_protection": "no", "photostable_sunscreen": "no", "boost_spf_of_others": "no", "antioxidant_under_uv": …
PubChem Annotations
Safety and regulatory annotations from PubChem (NCBI) aggregated sources.
Safety (1)
Carcinogen Classification
No indication of carcinogenicity to humans (not listed by IARC).
Source: Toxin and Toxin Target Database (T3DB)
Function Categories & List Membership
Cosmetic/Chemical Function Categories
Flavouring and nutrient
Softener and conditioner
Regulatory List Membership (2)
EPA Safer Chemical Ingredients List (SCIL)
FDA Substances Added to Food (EAFUS)
Expert Verdict
Expert safety assessment and concern-level summary for L-Methionine.
Regulatory Flags
epa_safer_alternative
fda_food_additive
Known Synonyms
2-Amino-4-methylthiobutanoic acid (S)-
2-Amino-4-(methylthio)butyric acid, (S)-
EINECS 200-562-9
Methioninum
UNII-AE28F7PNPL
(2S)-2-amino-4-(methylsulfanyl)butanoate
(2S)-2-amino-4-(methylsulfanyl)butanoic acid
(2S)-2-amino-4-methylsulfanyl-butanoic acid
(L)-methionine
(S)-(+)-methionine
(S)-2-Amino-4-(methylthio)butanoate
(S)-2-amino-4-(methylthio)-Butanoate
(S)-2-amino-4-(methylthio)-Butanoic acid
(S)-2-amino-4-(methylthio)butyric acid
(S)-methionine
2-Amino-4-(methylthio)butyrate
2-Amino-4-methylthiobutanoate
A-Amino-g-methylmercaptobutyrate
A-Amino-g-methylmercaptobutyric acid
G-Methylthio-a-aminobutyrate
Chemical Function
Flavouring and nutrient
Softener and conditioner
Regulatory Lists
inert_ingredient; Pesticides
inert_ingredient; non_food_use; Pesticides
Europe
food_additive; Substances Added to Food (formerly EAFUS) (2/2019)
SCIL (9/2019)
pharmaceutical
Cross-Vertical Safety Context
Same-CAS public records found in pharmaceutical data.
SOURCE
ChEMBL / DrugCentral / FAERS
DB_PHARMA CAS match
Pharmaceutical Data
Same-CAS rows from the pharmaceutical spoke database.
Compound
METHIONINE
ChEMBL ID
CHEMBL42336
Max Phase
3
Adverse Event Associations
104
Frequently Asked Questions
Is L-Methionine allowed in the EU?
L-Methionine EU regulatory status: permitted. This is based on EU Regulation 1223/2009 and its amendments.
What does L-Methionine do in cosmetics?
L-Methionine functions as: Antistatic, Hair Conditioning, Skin Conditioning, Antioxidant. It is classified as a cosmetic ingredient in our database. CAS number: 63-68-3.
Is L-Methionine used outside cosmetics?
L-Methionine also appears in industrial chemical safety and pharmaceutical data. The cross-vertical cards on this page render same-CAS public rows from the matched databases.
Compliance Tools
Check L-Methionine compliance across multiple jurisdictions:
Ingredient Decoder
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82 Allergen Checker
Check for EU declarable fragrance allergens
Substance Compliance
Check compliance across multiple jurisdictions
MoS Calculator
Calculate Margin of Safety using SCCS methodology
Heavy Metal Limits
Compare limits across jurisdictions
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