Regulatory Status
For full compliance data across 55 jurisdictions, use the Substance Compliance tool.
Safety Data
Calculate MoS for your specific formulation with the MoS Calculator.
Toxicological Studies
10 study endpoints found for L-Leucine. 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 | 8000 mg/kg bw/day | oral | rat | Short Term Toxicity | COSMOS_DB |
| NOAEL | 7200 mg/kg bw/day | oral | rat | Short Term Toxicity | COSMOS_DB |
| NOAEL | 5000 mg/kg bw/day | oral | rat | Short Term Toxicity | COSMOS_DB |
| NOAEL | 1500 mg/kg bw/day | oral | rat | Reproductive | COSMOS_DB |
| NOAEL | 7000 mg/kg bw/day | oral | rat | Reproductive | COSMOS_DB |
| dose_tested | 8000 mg/kg bw/day | oral | rat | Short Term Toxicity | COSMOS_DB |
| dose_tested | 7200 mg/kg bw/day | oral | rat | Short Term Toxicity | COSMOS_DB |
| dose_tested | 5000 mg/kg bw/day | oral | rat | Short Term Toxicity | COSMOS_DB |
| NOAEL | 5 other | oral | rat | oral | REACH |
| LOEL | 2000 mg/kg bw/day | oral | rat | oral | REACH |
Expert Verdict
L-Leucine is a branched-chain amino acid that inhibits lipid peroxidation by accessing fat-soluble ROS in the lipid phase, classified alongside valine and tyrosine in this antioxidant subcategory. Its hydrophobic isobutyl side chain provides strong lipid-phase partitioning. Also widely used as a powder flow agent and texture modifier. GRAS and CIR-class safe with no restrictions.
Regulatory Flags
Frequently Asked Questions
Is L-Leucine safe in cosmetics?
L-Leucine is a branched-chain amino acid that inhibits lipid peroxidation by accessing fat-soluble ROS in the lipid phase, classified alongside valine and tyrosine in this antioxidant subcategory. Its hydrophobic isobutyl side chain provides strong lipid-phase partitioning. Also widely used as a powder flow agent and texture modifier. GRAS and CIR-class safe with no restrictions. The EU classifies L-Leucine as "permitted". Safety rating: EXCELLENT. 10 toxicological study endpoint(s) are available in our database.
Is L-Leucine allowed in the EU?
L-Leucine EU regulatory status: permitted. This is based on EU Regulation 1223/2009 and its amendments.
What does L-Leucine do in cosmetics?
L-Leucine functions as: Essential branched-chain amino acid that inhibits lipid peroxidation and enhances accessibility of fat-soluble ROS. The hydrophobic isobutyl side chain partitions into lipid membranes and sebaceous environments, scavenging fat-soluble reactive oxygen species and disrupting lipid peroxidation chain reactions. Also commonly used as a slip agent and texture modifier in cosmetic powder formulations.. It is classified as a Antioxidant in our database. CAS number: 61-90-5.
What is the Margin of Safety for L-Leucine?
not established The Margin of Safety (MoS) is calculated using SCCS methodology. A MoS above 100 is generally considered safe. Use the MoS Calculator tool to calculate MoS for your specific formulation and product category.
What is the NOAEL for L-Leucine?
The NOAEL (No Observed Adverse Effect Level) for L-Leucine is 8000 mg/kg bw/day based on a Short Term Toxicity study via oral route in rat. A total of 10 study endpoints are available. Source: COSMOS_DB.
Compliance Tools
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Related Ingredients
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