Ingredient dictionary

Trimethylsiloxysilicate

Trimethylsiloxysilicate is a silicone resin that forms a thin, flexible film on skin, hair or lashes. Its main job is to add shine, smoothness and water resistance. It is on the label of 41 products in our library. Checked against our library November 6, 2026.

The catch: it is grouped with silicones, which some people avoid for curly-hair routines or to cut down on build-up. Silicones are generally considered safe and give slip and shine.

Silicones. Silicones are safe and give slip and shine. Some people avoid them for curly-hair routines or to cut build-up.

What Trimethylsiloxysilicate does

Forms a smooth, flexible film
Adds shine and gloss
Helps makeup stay put

Trimethylsiloxysilicate is a silicone resin made from silica-type building blocks capped with trimethylsilyl groups. Formulators use it because it dries into a thin, flexible film. That film helps pigments and powders stay put and gives a soft, glossy look.

In eyeshadow and eyeliner, it helps color wear longer and resist smudging. On the skin it feels light and slightly slick at first, then settles into a smooth finish. Because the film is durable, makeup removal may take a little more effort than with a simple water-based formula.

Good for

Eyeliner, eyeshadow and other makeup that needs shine and staying power on the eyelids.

Be careful if

It is grouped with silicones, which some people avoid for curly-hair routines or to cut down on build-up. Silicones are generally considered safe and give slip and shine.

Frequently asked questions

Is trimethylsiloxysilicate the same as dimethicone?

No. Both are silicones, but they are different types. Dimethicone is a linear silicone that feels slippery, while trimethylsiloxysilicate is a branched resin that forms a firmer, more durable film on the skin.

Is trimethylsiloxysilicate safe for sensitive skin?

It is generally well tolerated and is used in many makeup products. As with any cosmetic, people with sensitive skin may react to a particular formula, so a patch test is a sensible first step. Anyone with a known reaction should check the full ingredient list.