Alanine
Also known as Alanine, L-Alanine, 2-Aminopropanoic acid
“CIR Expert Panel says: safe as used in cosmetics.”
Alanine (CAS 56-41-7; L-Alanine, the simplest chiral α-amino acid with a methyl side chain) is used in cosmetics as a skin- and hair-conditioning humectant. The CIR Expert Panel assessed all 21 α-amino acids and their simple salts in cosmetics (Burnett et al., IJT 32(6 Suppl):41S-64S, 2013; PMID 24335967) and concluded they are safe in the present practices of use and concentration; Alanine is explicitly named in the assessment. The QRT records Alanine with Finding=S (Safe), no qualifying conditions, citing IJT 32(S4):41-64, 2013. Cosmetic usage data from Table 4 of the CIR assessment reported 19 total uses for Alanine at concentrations up to 0.4%, which is substantially lower usage frequency than Glycine, Proline, or Serine in the same assessment.
Simplest chiral α-amino acid: single methyl side chain distinguishes it from glycine; L-stereoisomer is proteinogenic and endogenous to all living tissues
Natural moisturizing factor (NMF) component: free amino acids including alanine are endogenous constituents of the stratum corneum that contribute to skin hydration
Skin- and hair-conditioning humectant: attracts and binds water; used at concentrations up to 0.4% in cosmetic formulations (19 reported uses, lower frequency than glycine/proline/serine in the same CIR group assessment)
CIR Expert Panel concluded alanine is safe as used in cosmetics in the practices of use and concentration of the 2013 safety assessment:41-64, 2013; QRT Finding=S)
- · No known sensitization concerns identified in the CIR group assessment
- · Usage concentrations are low (up to 0.4% per Table 4 of the CIR assessment); no irritation or sensitization signals at reported use levels
CIR Quick Reference Table (12/2017, revised 07/2018) — Alanine row: Finding=S, Citation=IJT 32(S4):41-64, 2013
“Alanine | S | | IJT 32(S4):41-64, 2013”— QRT-122017revised072018.pdf, p. 3