Ingredient dictionary

Stearalkonium Bentonite

A clay-based thickener made from bentonite treated with a stearalkonium compound, used to give oils and other non-water formulas body. It is on the label of 10 products in our library. Checked against our library November 6, 2026.

The catch: none for most people; check the full product list if your skin reacts easily.

What Stearalkonium Bentonite does

Thickens oils and other non-water formulas
Builds a gel-like texture
Keeps pigments and solids evenly suspended

Bentonite is a soft clay formed mostly from volcanic ash, and its main mineral is montmorillonite. This version has been treated with a stearalkonium compound, a long-chain quaternary ammonium, which makes the clay surface oil-loving. That change lets it blend into oils instead of staying separate.

Formulators use it to build body in water-free products. In oil, the clay particles link into a loose network that turns a runny liquid into a soft gel. The same network helps hold pigments and powders evenly in place. On skin, the finished product usually feels smooth and substantial rather than watery.

Good for

Anhydrous products, such as oil gels and some makeup, that need a thick, stable base.

Be careful if

Nothing in particular for most skin types.

Frequently asked questions

Is Stearalkonium Bentonite the same as regular bentonite?

No. Plain bentonite is a clay that mixes best with water. This version is treated so it blends into oils, which suits water-free products like oil gels and some makeup.

Is Stearalkonium Bentonite safe for sensitive skin?

It is generally well tolerated in cosmetics, but no ingredient suits every skin type. If your skin is sensitive, read the full ingredient list and try a small patch test before using a new product on your face.