What it is
This is a branched, cage- or network-structured silicone resin built around phenyl-substituted siloxane units, which gives it good film-forming properties and compatibility with other silicones. In sunscreens and tinted products it helps the formula spread evenly and set into a smooth, uniform layer that resists transfer. Its phenyl content contributes a glossy, refined finish and helps disperse pigments and filters.
Safety & warnings
Silicone resins of this type are generally well tolerated, non-sensitizing, and not associated with fragrance allergens. They sit on the surface as an inert film rather than penetrating the skin.
Origin & sourcing
Synthetic silicone (organosilicon) resin.
Questions everyone asks
What is polyphenylsilsesquioxane used for?
It is a silicone resin that acts as a film former, helping the product set into a smooth, even, long-wearing layer with a refined finish.
Is it the same as regular dimethicone?
No. It is a more rigid, resin-like silicone with phenyl groups, used mainly for film formation and finish rather than as a simple lightweight emollient.