Polymethylsilsesquioxane is a silicone-based spherical powder used in skincare and cosmetics to impart a smooth, soft-focus, mattifying feel and improve spreadability. It is a formulation/texture ingredient rather than a treatment active.
| Reported effect | How often | Notes |
|---|---|---|
Skin irritation | Rare | Mild irritation occasionally reported, generally considered well tolerated and non-irritating. |
Contact allergy / sensitization | Very rare | Silicone-based powders rarely cause allergic reactions. |
Pore-clogging concerns | Very rare | Generally regarded as non-comedogenic; clogging is uncommon. |
Frequencies reflect typical cosmetic use reported in the literature, not a guarantee for your skin.