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The ingredient, explained

Pca

PCA has published research relevant to cosmetic safety assessment.

HumectantMoisturising
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Ingredient guide

What it is and what it does

L-2-Pyrrolidone-5-carboxylic acid

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

Humectant
Helps attract and retain moisture.
Moisturising
A technical role associated with increasing skin water content.

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 assessment reviewed cosmetic exposure and toxicology for PCA and four salts, with a formulation condition against formation of N-nitroso compounds.

What this does not tell us

Safety assessment, not a hydration efficacy trial. Group data include substantial sodium PCA evidence. Findings are limited to the report's cosmetic uses and concentrations.

Sources for this summary. PubMed 31522652 ↗

Research review checked Oct 1, 2026

Selective exact-identity review of 6 supplied local candidates and the targeted primary-source search recorded below. Bounded review, not a systematic search.

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

Read the 1 selected study

Follow the formula

Products containing this ingredient

All 36 products ↗

From the Serenfold edit. Linked by the ingredient list, without an efficacy ranking.

Names and identifiers

Registry identity

L-2-Pyrrolidone-5-carboxylic acid

INCI name on ingredient lists
PCA
CAS registry number
98-79-3
EC number
202-700-3
Other recorded names (1)
  • pidolic acid

Sources for this ingredient record