What it is
Pentaerythrityl tetraisostearate is a viscous ester made from pentaerythritol and isostearic acid, valued for its cushiony emollient feel and its ability to wet and disperse powders. In sunscreens, especially mineral and tinted types, it helps suspend titanium dioxide, zinc oxide, and other pigments for an even, smooth application. It also contributes a rich, conditioning skin feel.
Safety & warnings
This ester is generally well tolerated and considered low-irritation in cosmetic products. It is a richer, more occlusive emollient than lighter esters, so very blemish-prone users may prefer to monitor how heavily emollient formulas suit them, though it is not flagged as a strong comedogen.
Origin & sourcing
Synthetic. It is produced by esterifying pentaerythritol with isostearic acid, a branched fatty acid.
Questions everyone asks
Why is pentaerythrityl tetraisostearate used in mineral sunscreens?
Its strong powder-wetting and dispersing ability helps evenly suspend pigments like titanium dioxide and zinc oxide for smoother application.
Is it a heavy or light emollient?
It is a richer, more cushiony ester than lightweight emollients, contributing a conditioned, smooth feel.