The ingredient, explained

Tryptophan

A published safety assessment explicitly covers TRYPTOPHAN.

AntistaticHair conditioningMasking

Explore connections

Ingredient guide

What it is and what it does

2-Amino-3-indol-3-ylpropanoic acid

About this ingredient: EU CosIng ingredient registry (via Open Beauty Facts taxonomy) ↗

Antistatic: Reduces the build-up of static electrical charge on surfaces.
Hair conditioning: Improves cosmetic hair properties such as softness, shine or combability.
Masking: Reduces or conceals the formula's underlying odour or taste.

Function definitions: European Commission ingredient function definitions (SCCNFP/0299/00, pages 16 to 20) ↗

Registry functions describe possible formulation roles, not results for a finished product. A dictionary entry is not an approval or a safety assessment.

A closer look

What the research shows

Safety assessment

The panel accepted the described amino-acid cosmetic uses after irritation and sensitization review.

What this does not tell us

Published safety assessment, not an efficacy trial. Its conclusion is limited to the reported cosmetic uses and concentrations, and relies partly on group read-across where individual data are missing. It does not establish current regulatory status or guarantee tolerance for every formulation. Group read-across and stereoisomer coverage limits remain explicit. Dietary depletion and skin-conductance studies do not establish topical skin benefit.

Sources for this summary. PubMed 24335967 ↗

Research review checked Oct 1, 2026

Review supplied candidate titles and available abstracts selectively for exact identity; targeted primary PubMed/publisher searches. This is not an exhaustive systematic review.

Ingredient research is not proof that a product containing this ingredient works.