What it is
Ethylhexyl Polyhydroxystearate is an ester of polyhydroxystearic acid and 2-ethylhexanol. In cosmetics it acts as an emollient and a wetting and dispersing agent that helps suspend mineral powders such as titanium dioxide, zinc oxide, and color pigments evenly throughout a formula. This improves smoothness and even application but contributes no UV protection itself.
Safety & warnings
As an oil-soluble emollient ester it is generally well tolerated and is not a recognized fragrance allergen. It is not among the standard comedogenic oils, though individuals with very acne-prone skin may wish to monitor rich formulas.
Origin & sourcing
Produced synthetically by esterifying polyhydroxystearic acid, derived from hydroxystearic fatty acids, with 2-ethylhexanol.
Questions everyone asks
Why is this ester used with mineral sunscreens?
It helps wet and evenly disperse mineral UV filter and pigment particles, reducing clumping and improving how smoothly the product applies.
Is it itself a UV filter?
No. It is a dispersing emollient that helps deliver the actual mineral filters; it does not block UV by itself.