Zinc PCA

Zinc PCA is the zinc salt of pyrrolidone carboxylic acid (PCA), one of the components of the skin's own natural moisturising factor. The pairing does two jobs at once: PCA is a humectant that helps the surface hold water, and zinc contributes the astringent, shine-controlling character the ingredient is known for.

In cosmetic literature and supplier data, zinc salts are described as sebum-regulating and as having a purifying effect on the skin surface, which is why zinc PCA appears in formulas for oily, combination and blemish-prone skin. Unlike alcohol-based astringents it does this without stripping, and the PCA portion keeps the finish comfortable rather than tight.

It is water-soluble, colourless and stable, and is used at low percentages. It sits well alongside niacinamide and hydroxy acids in a multi-active serum. Zinc in topical products is generally well tolerated; the main formulation consideration is keeping the total zinc content modest so the finish stays light.