What concentration of PCA is effective?

Typical effective concentrations of PCA are Typically used at 0.5-5% in cosmetic formulations, commonly found in moisturisers, serums, masks, and cleansers.

The Skin Formulary

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Researched by Helena DeMaria-Williams

Formula IngredientHumectant

PCA

Q: Can PCA cause skin irritation?

PCA has a low irritation risk. PCA is non-irritating and non-sensitising in clinical tests, as confirmed by the Cosmetic Ingredient Review (CIR) panel. It is naturally present in skin tissue, making adverse reactions very uncommon. No EU CosIng Annex II or III restrictions apply.

Q: Is PCA safe to use during pregnancy?

PCA is rated "safe" for pregnancy use. The CIR concluded that PCA is safe as used in cosmetic formulations. Topical application results in low skin penetration and minimal systemic absorption. PCA is naturally present in human skin tissue. No specific pregnancy risks have been identified, though clinical pregnancy-specific studies remain limited (MotherFigure; CIR safety review).

Q: Does PCA increase sun sensitivity?

PCA has a no sun sensitivity risk. PCA does not increase photosensitivity. No phototoxicity or photosensitisation has been observed in testing. No additional sun protection is required solely due to this ingredient.

Q: What skin types is PCA suitable for?

PCA is suitable for all skin types, dry, dehydrated, sensitive, mature, normal, oily, combination.

INCI: PCA

PCA (pyrrolidone carboxylic acid), also known as pidolic acid or L-pyroglutamic acid, is a naturally occurring amino acid derivative found in human skin as a key component of the Natural Moisturising Factor (NMF). It accounts for approximately 12% of NMF composition, making it the second largest NMF component after amino acids. It works as a humectant by attracting and binding water to the skin, helping to maintain optimal hydration levels.

What does this do in a formula?

hydration, moisture retention, skin barrier support, skin conditioning, NMF replenishment

Is PCA safe? Key considerations

Can PCA cause irritation?

Low Risk

PCA is non-irritating and non-sensitising in clinical tests, as confirmed by the Cosmetic Ingredient Review (CIR) panel. It is naturally present in skin tissue, making adverse reactions very uncommon. No EU CosIng Annex II or III restrictions apply.

Does PCA increase sun sensitivity?

No Risk

PCA does not increase photosensitivity. No phototoxicity or photosensitisation has been observed in testing. No additional sun protection is required solely due to this ingredient.

Is PCA safe during pregnancy?

Safe

The CIR concluded that PCA is safe as used in cosmetic formulations. Topical application results in low skin penetration and minimal systemic absorption. PCA is naturally present in human skin tissue. No specific pregnancy risks have been identified, though clinical pregnancy-specific studies remain limited (MotherFigure; CIR safety review).