Pyrrolidone carboxylic acid. A primary NMF component (~12%). Humectant, retains moisture in the stratum corneum.
Topical application
BLimited evidence. One RCT or several controlled studies with limitations.
Natural NMF component, effective humectant.
PCA (Pyrrolidone Carboxylic Acid) is a natural component of the skin's natural moisturizing factor (NMF). Makes up 12% of NMF in the stratum corneum. A derivative of the amino acid pyroglutamate. Mechanism. Strong humectant – binds water in the stratum corneum 3 times more efficiently than glycerin. Restores NMF deficit in dry skin, atopic dermatitis, xerosis. Maintains skin pH around 5.5. Where applied. Creams, serums, toners, shampoos (0.5–5%). Often in salt forms – Sodium PCA, Zinc PCA. In Spain in Sesderma, Martiderm, La Roche-Posay Lipikar lines. An alternative to hyaluronic acid for moisturizing effect. Evidence base. Tabachnick 1982 RCT (one of the first) showed 30% skin hydration increase in 7 days at 2% PCA. The Loden 2003 meta-analysis confirms PCA efficacy as a component of emollient therapy in atopy and xerosis. Safety. CIR confirmed safety. Hypoallergenic, non-comedogenic, does not photosensitize. Pregnancy and lactation – topically safe. Acceptable at any stage including face, breast, abdomen.
Irritation potential
LowAllergen risk
LowPregnancy
SafeSuitable for
The Evigrade extension adds an evidence panel to Wildberries, Goldapple, Letu, iHerb, Sephora and 12 more stores. This ingredient and every other one in the product show evidence-tier, allergen risk and pregnancy/lactation flags at a glance.
PCA is considered safe during pregnancy at typical cosmetic concentrations. Systemic absorption through the skin is minimal.
PCA suits: normal, dry, oily, combination, sensitive.
Pyrrolidone carboxylic acid.
The INCI name is PCA. It may also appear as: Pyrrolidone Carboxylic Acid, L-PCA.
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