PCA
2-Pyrrolidone-5-carboxylic acid (L-pyroglutamic acid, free acid form)
Free acid form of NaPCA; most hygroscopic NMF amino acid; second-largest NMF component at ~12%; more acidic than sodium salt so may lower formulation pH; well tolerated
Function & Common Use
Humectant / Skin-Conditioning Agent
Humectants
Serums, toners, moisturizers, hair care
Synthetic (also natural: biosynthesized from glutamic acid)
Concentration Limits
None
None
None
None
Format restriction: None
Baby restriction: No
Pregnancy: No
IFRA: No
Frequently Asked Questions
Is PCA safe to use in skincare?
PCA has a Low concern rating from The Clean Sheet. Free acid form of NaPCA; most hygroscopic NMF amino acid; second-largest NMF component at ~12%; more acidic than sodium salt so may lower formulation pH; well tolerated
Is PCA allowed in India?
PCA is currently classified as "Permitted" under Indian cosmetics regulations. The maximum permitted concentration is None.
What is PCA used for in cosmetics?
PCA functions as: Humectant / Skin-Conditioning Agent. It is commonly found in: Serums, toners, moisturizers, hair care.
Can PCA cause an allergic reaction?
Yes. PCA has an allergen flag (No). If you have sensitive skin or known fragrance/contact allergies, patch-test products containing this ingredient before full use.
Is PCA safe for babies?
PCA has baby/child restrictions: No. Avoid using products containing this ingredient on infants unless specifically formulated and labelled for baby use.
Regulatory Status
EU Annex: None
Identifiers
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