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 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
Excellent safety profile as a naturally occurring essential amino acid; non-toxic, non-sensitizing at typical cosmetic use levels; widely consumed as a dietary supplement with extensive human safety data. Leucine is a branched-chain essential amino acid (crystallizes in white platelets - from Greek leukos = white). It functions as a natural protein building block, stimulates protein synthesis in skin cells, and provides anti-static performance in hair care; also used as a powder flow agent in...
Regulatory Flags
Frequently Asked Questions
Is Leucine safe in cosmetics?
Excellent safety profile as a naturally occurring essential amino acid; non-toxic, non-sensitizing at typical cosmetic use levels; widely consumed as a dietary supplement with extensive human safety data. Leucine is a branched-chain essential amino acid (crystallizes in white platelets - from Greek leukos = white). It functions as a natural protein building block, stimulates protein synthesis in skin cells, and provides anti-static performance in hair care; also used as a powder flow agent in... The EU classifies Leucine as "permitted". Safety rating: MODERATE. 10 toxicological study endpoint(s) are available in our database.
Is Leucine allowed in the EU?
Leucine EU regulatory status: permitted. This is based on EU Regulation 1223/2009 and its amendments.
What does Leucine do in cosmetics?
Leucine functions as: Antistatic, Hair Conditioning, Skin Conditioning. It is classified as a cosmetic ingredient in our database. CAS number: 61-90-5.
What is the Margin of Safety for 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 Leucine?
The NOAEL (No Observed Adverse Effect Level) for 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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