The ingredient, explained

Undecylenoyl Phenylalanine

Research examined UNDECYLENOYL PHENYLALANINE under the stated study conditions.

Skin conditioning

Explore connections

Ingredient guide

What it is and what it does

L-Phenylalanine, N--1-Oxo-10-Undecenyl--

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

Skin conditioning: A broad cosmetic role for maintaining skin condition. It does not identify a particular clinical benefit.

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

Human research on a combination

Adding 1% undecylenoyl phenylalanine to 5% niacinamide reduced hyperpigmentation appearance more than niacinamide-only and vehicle formulations.

What this does not tell us

Two trials with different populations; the first had 80 women, the second reports sites rather than a clear participant total. Niacinamide is co-active; no standalone ingredient arm.

Sources for this summary. PubMed 19958429 ↗

Research review checked Oct 1, 2026

Read exact local candidate abstracts first; select identity-relevant papers; targeted primary PubMed/publisher searches. This is not an exhaustive systematic review.