Po
Polymethylsilsesquioxane
Polymethylsilsesquioxane
A silicone resin in the form of tiny spherical powder beads that give a soft-focus, mattifying, velvety finish.
What it does
Polymethylsilsesquioxane is a silicone resin supplied as microscopic spherical beads. Those spheres roll across the skin to give a smooth, silky glide and scatter light to create a soft-focus, slightly blurred finish, while absorbing some surface oil for a matte feel. It is common in primers, makeup, and mattifying moisturizers. It is a texture-and-finish ingredient rather than a skin active.
Also known as
pmsq
Browse all 668 ingredients — grouped by what they do, each with whatever evidence we can cite.
This page is public so a shared ingredient card always has its sources behind it — and so you can check them without an account.
Want more like this?
Every evidence-based flag cites its source, Drop tells you when your routine is complete, and it helps you simplify — instead of selling you more. The app launches on iOS and Android in October 2026. Rate my routine works today at /rate — no sign-in.