Potassium PCA
molecular structure · PubChem
AKA: Potassium 5-oxo-L-prolinate, 4810-50-8, Potassium pidolate, KALIDONE, L-Proline, Monopotassium salt, POTASSIUM L-PYROGLUTAMATE
Synthetic
Humectant
Amino Acid
Clean
The CIR Expert Panel concluded that PCA (i.e., 2-pyrrolidone-5-carboxylic acid), calcium PCA, magnesium PCA, potassium PCA, and sodium PCA are safe in cosmetics in the present practices of use and concentration described in this safety assessment. PCA and its salts should not be used in cosmetic products in which N-nitroso compounds can be formed.
Effective at 0.38%
Formula
C5H6KNO3
Mol. Weight
167.20
CAS #
4810-50-8
Form
Liquid
Functions
Humectant
A moisture magnet. Pulls water from the air and deeper skin layers up to the surface to keep skin plump and hydrated.
Locks In Moisture
Traditional Use
Potassium salt of pyrrolidone carboxylic acid, a naturally occurring humectant found in skin. Developed in the 1970s as a synthetic moisturizing agent to mimic the skin's natural water-binding compounds.
EWG
1
CIR
Safe as used
Pregnancy
Yes
CIR Safety Findings
Not a Sensitizer
medical-approval
all-shades-safe
Concentration Guide
0.005%
0.75%
0%1%
Reported use
CIR reported use: 0.01-0.2 | 0.1-0.18 | 0.005-0.75
Regulatory Agencies
Skin Types
●all-skin-types
Best For
Dryness
Pregnancy & Breastfeeding Safe
Yes
The paper trail
🔬Peer-reviewednone on file
⚖️Regulatory1 listing →
🛡️Safety-assessed3 reviews →
Counts, not a verdict. A listing isn't a study. The trail, you decide.
Verified Jun 2026
Data: PubChem · CosIng · EWG · CIR