PCA
AKA “L-Pyroglutamic acid, 98-79-3, Pyroglutamic acid, Pidolic acid, 5-oxo-L-proline, (2S)-5-oxopyrrolidine-2-carboxylic acid, pyroglu, GLUTIMIC ACID, (S)-(-)-2-Pyrrolidone-5-carboxylic acid, 5-L-Oxoproline”
Humectant
Ingredient Facts
PCA
AKA: L-Pyroglutamic acid, 98-79-3, Pyroglutamic acid, Pidolic acid, 5-oxo-L-proline, (2S)-5-oxopyrrolidine-2-carboxylic acid, Pyroglu, GLUTIMIC ACID, (S)-(-)-2-Pyrrolidone-5-carboxylic acid, 5-L-Oxoproline
Humectant · Humectant · EWG: 2
Synthetic
Humectant
Amino Acid
Clean
L-2-Pyrrolidone-5-carboxylic acid
Effective at 25.0%
Solubility 476000
Formula
C5H7NO3
Mol. Weight
129.11
CAS #
98-79-3
Form
Liquid
State
Solid; [Merck Index] White crystalline powder; [Alfa Aesar MSDS]
See origin →
Functions
Humectant
A moisture magnet. Pulls water from the air and deeper skin layers up to the surface to keep skin plump and hydrated.
Moisturising
Locks In Moisture
Traditional Use
Pyroglutamic acid (PCA) is a naturally occurring amino acid derivative that is a primary component of skin's natural moisturizing factor (NMF). Modern skincare began incorporating it in the 1970s-1980s once its hydrating mechanism was understood.
Skin Types
●all-skin-types
Best For
Dehydration
Pregnancy & Breastfeeding Safe
Yes
Verified Jun 2026
Data: PubChem · CosIng · EWG · CIR