Ingredient dictionary

Polymethylsilsesquioxane

A silicone resin made of tiny cross-linked particles that gives makeup and skincare a smooth, soft-focus feel. It is on the label of 13 products in our library. Checked against our library November 6, 2026.

The catch: it is a silicone, which is considered safe and gives slip and shine, but some people avoid silicones for curly-hair routines or to cut down on build-up.

Silicones. Smoothing film-formers ending in -cone or -siloxane, such as dimethicone.

What Polymethylsilsesquioxane does

Gives a smooth, soft-focus finish
Absorbs surface oil and shine
Improves slip and even spreading

Polymethylsilsesquioxane is made in a lab from methyl-based silicon building blocks. These link together into a network that forms tiny, round particles, usually sold as a fine powder. It belongs to the silicone family, which is why it feels slippery rather than greasy.

Formulators use it because the particles are smooth and light. They help a product spread evenly, soak up some surface oil, and scatter light so skin looks softer. In eyeshadow, it helps color glide and blend. In a moisturizer or after-sun lotion, it leaves a silky, lightweight feel rather than a heavy coat.

Good for

Suits people who like smooth, velvety textures in eyeshadow, moisturizers, and after-sun products.

Frequently asked questions

Is polymethylsilsesquioxane safe?

It is a silicone that is generally well tolerated and widely used in cosmetics. Most people do not react to it. If you have sensitive skin, patch testing a new product first is a sensible habit.

Is polymethylsilsesquioxane the same as dimethicone?

Both are silicones, but they differ. Dimethicone is a liquid that spreads into a slip layer. Polymethylsilsesquioxane is a solid, cross-linked resin used as a powder. If you avoid silicones for curly hair, check labels for both.