Sodium PCA is the sodium salt of pyrrolidone carboxylic acid, one of the most abundant Natural Moisturizing Factors (NMFs) found in human skin. It is a powerful humectant that attracts and binds moisture, helping maintain skin hydration, flexibility, and barrier function.
Key Skin Benefits
+ Part of skin's own NMF — highly biocompatible
+ Superior water-binding capacity (better than glycerin)
+ Helps maintain skin barrier integrity
+ Non-sticky, lightweight hydration
Pros
+ Identical to compound naturally found in skin
+ Very high moisture-binding capacity
+ Non-comedogenic and non-irritating
+ Works synergistically with other NMF components
Cons
− Can be sticky at high concentrations (>4%)
− Hygroscopic — needs proper packaging
− More expensive than glycerin
Specifications
Property
Value
Usage Areas
Face, Eye, Body, Hair
Product Type
Leave-On, Rinse-Off
Source
Plant-derived (amino acid) / Synthetic
Natural Level
Natural-derived
Safety Ratings
Metric
Rating
Skin Sensitivity
0/5 (none)
Comedogenic Rating
0/5
EWG Score
1/10
Regional Regulatory Limits
Region
Leave-on %
Rinse-off %
Status
EU (CosIng)
No limit
No limit
Allowed
US (CIR/FDA)
No limit
No limit
Allowed
Japan (MHLW)
No limit
No limit
Allowed
ASEAN
No limit
No limit
Allowed
China (NMPA)
No limit
No limit
Allowed
Typical Usage % by Product Type
Product Type
Typical %
Moisturizer / Serum
0.5 - 3%
Toner / Mist
1 - 2%
Hair conditioner
0.5 - 2%
References
Verdier-Sévrain S & Bonté F (2007) — Skin hydration: NMF review. PMID: 17207962