PCA (pyrrolidone carboxylic acid), jab sodium PCA ke form mein hota hai, to yeh skin ke natural moisturizing factor (NMF) ka ek natural component hota hai. Yeh water ko attract karta hai aur stratum corneum se bind karta hai. Skincare products mein iska use hydration improve karne aur skin ke moisture ko maintain karne ke liye hota hai.