Quick answer

Humectant derived from amino acids; Increases water content (hydration) in the uppermost layers of skin; Also part of skin’s natural moisturizing factor; Often linked with mineral electrolytes to further supercharge hydration within skin’s aquaporins Key benefits: Hydration.

PCA

Updated

L-2-Pyrrolidone-5-carboxylic acid

Purpose

Humectant derived from amino acids. Increases water content (hydration) in the uppermost layers of skin. Also part of skin’s natural moisturizing factor.

Rating

GOOD

Category

Humectant

INCI Purpose

HUMECTANT, MOISTURISING

Benefits

Hydration — Attracts and locks in moisture to keep skin plump and dewy

Alternative Names

At a Glance

Humectant derived from amino acids

Increases water content (hydration) in the uppermost layers of skin

Also part of skin’s natural moisturizing factor

Often linked with mineral electrolytes to further supercharge hydration within skin’s aquaporins

Article

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 moisturizing factor. This makes PCA a skin care ingredient that skin readily recognizes 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.

See: Natural Moisturizing Factor (NMF), Calcium PCA, Magnesium PCA, Potassium PCA, Sodium PCA, Copper PCA, NaPCA, Zinc PCA

References

International Journal of Toxicology, 2019, pages 5S-11S International Journal of Cosmetic Science, February 2017, pages 2-10, and December 2016, pages 567-575 Journal of Dermatological Science, December 2014, pages 231-239