Is L-Serine safe in cosmetics?
L-Serine has a safety rating of "GOOD" in our database. EU status: permitted. US status: permitted. 2 toxicological study endpoint(s) are available in our database.
L-Serine
INCI: SERINE
L-Serine (CAS 56-45-1) is a cosmetic cosmetic ingredient functioning as Skin Conditioning (Humectant), Hair Conditioning, NMF Component. NOAEL 2765 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 56-45-1 →
Auto-generated CPSR Part A draft with source citations
Function
Skin Conditioning (Humectant), Hair Conditioning, NMF Component
Safety Rating
GOOD
Chemistry & Identifiers
IUPAC Name
(2S)-2-amino-3-hydroxypropanoic acid
InChIKey
MTCFGRXMJLQNBG-REOHCLBHSA-N
Regulatory Status
EU EU Status
permitted
US US Status
permitted
US Notes
GRAS as direct food additive under 21 CFR 172.320; CIR safe in present practices of use
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-Serine.
Calculate MoS for your specific formulation with the MoS Calculator.
Toxicological Studies
2 study endpoints found for L-Serine. NOAEL (No Observed Adverse Effect Level) values are used to calculate the Margin of Safety per SCCS methodology.
| Endpoint | Value | Route | Species | Study Type | Source |
|---|---|---|---|---|---|
| NOAEL | =2765 mg/kg bw/day | oral | Rat | subchronic | ToxValDB_ECHA_IUCLID |
| NOAEL | =2905.1 mg/kg bw/day | oral | Rat | subchronic | ToxValDB_ECHA_IUCLID |
Pre-Calculated Safety Assessment
Pre-calculated NOAEL → SED → MoS audit trail for L-Serine across SCCS product categories, with measured dermal absorption where available.
Dermal Penetration Profile
Skin absorption and penetration characteristics of L-Serine, relevant to systemic exposure and MoS calculations.
Absorption %
2-5%
Penetration Level
surface
Penetration Depth
stratum corneum
Molecular Weight
105.1 Da
Log P
-3.0
Systemic Absorption
minimal
Topical Bioavailability
1-3%
Safety Margin Factor
low
Vehicle Dependent
Yes — absorption varies by formulation
Source: Amino Acids 2011
EPA ToxValDB — Toxicity Values
7 toxicity values from EPA ToxValDB (aggregated from CCTE, HPV, ToxRefDB, IRIS, and other regulatory dossiers).
| Endpoint | Value | Species | Route | Duration | Source |
|---|---|---|---|---|---|
| LD50 | =14000 mg/kg | Rat | oral | - | ECHA IUCLID |
| LD50 | >2000 mg/kg | Rat | oral | - | ECHA IUCLID |
| NOAEL | =2765 mg/kg-day | Rat | oral | subchronic | ECHA IUCLID |
| NOAEL | =2905.1 mg/kg-day | Rat | oral | subchronic | ECHA IUCLID |
| NOEL | =799.9 mg/kg-day | Rat | oral | short-term | ECHA IUCLID |
| NOEL | =903.9 mg/kg-day | Rat | oral | short-term | ECHA IUCLID |
| NOEL | =3000 mg/kg-day | Rat | oral | subchronic | ECHA IUCLID |
ECHA REACH Registration
European Chemicals Agency REACH dossier and Substances of Very High Concern listing.
Registration Type
Full
Tonnage Band
100 - 1,000 tonnes
Substance Type
SUBSTANCE
SVHC Candidate
No
Additional Ingredient Properties
10 property records from structured ingredient metadata.
acne
{"cas_number": "56-45-1", "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": "hydration-plumping, barrier-repair", "mechanism_of_action": "Building block for proteins, NMF component", "target_skin_layer": "epidermis", "collagen_stimulation": "Mild", "elastin_protection": "Mild", "wrinkle_reduction_pct": "6-12", "clinical_study_duration_weeks": "8", "sample_size": "25", "double_blind": "Yes", "placebo_controlled": "Yes", "published_journal": "Int J Cosm…
anti_pollution
{"cas_number": "56-45-1", "ingredient_class": "other", "primary_mechanism": "barrier_reinforcement", "pollution_types_targeted": "PM2_5", "IR_A_protection": "no", "visible_light_protection": "no", "digital_screen_protection_claim": "no", "PAH_neutralization": "no", "ozone_protection": "no", "mitochondrial_protection": "no", "Nrf2_activation": "no", "AhR_pathway_modulation": "no", "NF_kB_inhibition…
concentration
{"min_concentration_pct": "0.1", "max_concentration_pct": "2.0", "typical_concentration_pct": "1.0", "product_type": "Moisturizer", "function_at_concentration": "Hydration, barrier support", "source": "Clinical literature; Supplier TDS"}
dermal_absorption
{"molecular_weight_da": "105.1", "log_p_value": "-3.0", "skin_penetration_level": "surface", "penetration_depth": "stratum corneum", "absorption_pct": "2-5", "systemic_absorption": "minimal", "penetration_enhancer": "no", "occlusion_effect": "no", "vehicle_dependent": "yes", "skin_barrier_effect": "strengthens", "bioavailability_topical_pct": "1-3", "safety_margin_factor": "low", "source": "Amino …
hair_care
{"hair_function": "protein-treatment", "hair_type_suitability": "all", "curl_pattern_suitability": "all", "porosity_suitability": "all", "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": "strengthen…
humectant
{"cas_number": "56-45-1", "ingredient_class": "humectant/NMF_component/amino_acid", "molecular_weight_Da": "105.09", "chemical_type": "amino_acid", "water_binding_mechanism": "hydrogen_bonding/hygroscopic", "water_holding_capacity_g_per_g": "0.3-0.5", "hygroscopicity_at_50_RH": "moderate", "hygroscopicity_at_80_RH": "good", "NMF_component": "yes", "NMF_percentage_natural": "1-2", "TEWL_reduction_p…
pediatric_safety
{"safe_for_newborn_0_6m": "yes", "safe_for_infant_6_12m": "yes", "safe_for_toddler_1_3y": "yes", "safe_for_child_3_12y": "yes", "safe_for_teen_12_18y": "yes", "pediatric_max_concentration_pct": "5.0", "adult_max_concentration_pct": "5.0", "pediatric_dermal_absorption_factor": "normal", "diaper_area_safe": "yes", "pediatric_allergy_prevalence": "low", "banned_in_children_products_eu": "no", "banned…
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
Regulatory List Membership (1)
FDA Substances Added to Food (EAFUS)
Expert Verdict
Expert safety assessment and concern-level summary for L-Serine.
Regulatory Flags
fda_food_additive
NOAEL Studies Summary
View details ->Public NOAEL study rows linked to L-Serine by CAS number or substance name.
Studies
2
Lowest NOAEL
2765 mg/kg bw/day
Highest NOAEL
2905.1 mg/kg bw/day
ToxValDB_ECHA_IUCLID
Chemical Function
Flavouring and nutrient
Regulatory Lists
Canada; consumer_product; Substances in Products - Canada (4/2014)
food_additive; Substances Added to Food (formerly EAFUS) (2/2019)
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
SERINE
ChEMBL ID
CHEMBL11298
Max Phase
3
Adverse Event Associations
3
Frequently Asked Questions
Is L-Serine allowed in the EU?
L-Serine EU regulatory status: permitted. This is based on EU Regulation 1223/2009 and its amendments.
What does L-Serine do in cosmetics?
L-Serine functions as: Skin Conditioning (Humectant), Hair Conditioning, NMF Component. It is classified as a cosmetic ingredient in our database. CAS number: 56-45-1.
What is the NOAEL for L-Serine?
The NOAEL (No Observed Adverse Effect Level) for L-Serine is =2765 mg/kg bw/day based on a subchronic study via oral route in Rat. A total of 2 study endpoints are available. Source: ToxValDB_ECHA_IUCLID.
Is L-Serine used outside cosmetics?
L-Serine 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-Serine compliance across multiple jurisdictions:
Ingredient Decoder
Paste a full ingredient list for instant analysis
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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