PCA
INCI: pyrrolidone carboxylic acid
Reviewed by Rosie · Last updated 14 Aug 2026
Also known as: sodium PCA, calcium PCA, magnesium PCA, potassium PCA
EWG Safety Score
PCA products at Skintique
View all →What Is PCA?
PCA (which stands for pyrrolidone carboxylic acid) is an amino acid-derived ingredient that functions as a humectant. As such, it increases water content (hydration) in the uppermost layers of skin. It is also part of skin’s intercellular matrix and plays an influential role in what’s known as skin’s natural moisturising factor. This makes PCA a skin care ingredient that skin readily recognises and knows how to utilize.
Several mineral-based derivatives of PCA are used in skin care, including sodium PCA, calcium PCA, magnesium PCA, and potassium PCA. Linking these mineral electrolytes with PCA allows them to work within skin’s aquaporins (water channels) to enhance hydration and train skin to maintain its moisture balance. This also helps strengthen skin’s barrier.
PCA has been deemed safe by the Cosmetic Ingredient Review Expert Panel. Their report surveyed products containing between 0.000012-1.9% PCA.
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