Ingredient dictionary

Hydrated Silica

Also listed as: Silicon Dioxide

Hydrated silica is a fine powder of silicon dioxide that holds water in its porous structure, mainly used to absorb oil and add a matte finish. It is on the label of 15 products in our library. Checked against our library November 6, 2026.

What Hydrated Silica does

Absorbs oil and sweat from the skin
Gives a soft, matte, non-shiny finish
Helps other ingredients spread smoothly

Hydrated silica is a form of silicon dioxide, the compound that makes up much of rock and sand. Most cosmetic grades are made in a factory. A liquid silicate is reacted with an acid, which forms solid silica particles. These are washed, dried and milled into a fine powder. The cosmetic form is amorphous, meaning its particles have no crystal pattern.

Formulators use it because its porous surface soaks up oil and sweat. It adds a soft, dry, matte feel and helps other ingredients spread evenly. In sunscreens, it can help a formula feel lighter and less greasy on the skin. Its powdery texture also makes it useful in makeup. It is generally well tolerated.

Good for

Oily and combination skin, and anyone who wants a lighter, less greasy feel from sunscreen or makeup.

Frequently asked questions

Is hydrated silica safe to use?

Hydrated silica is widely used and generally well tolerated. It is an amorphous form of silicon dioxide, meaning its particles have no crystal pattern. Anyone who notices irritation from a product should stop using it and ask a skin professional.

Why is hydrated silica in my sunscreen?

Sunscreens can feel heavy, and hydrated silica helps them feel lighter and more even on the skin. It is not a UV filter, so it does not replace the active sun filters in the formula.