Bentonite

Benefits
Lightening

What is Bentonite?

Bentonite is a naturally occurring smectite clay formed from the alteration of volcanic ash deposits, primarily composed of montmorillonite, an aluminosilicate mineral with a layered structure rich in water and exchangeable cations. This composition gives it exceptional swelling capacity in water, creating viscous gels. In cosmetics, it appears in categories like clay masks, purifying cleansers, shampoos, and lotions. It functions by adsorbing oils and impurities through its high surface area and negative charge, which binds positively charged molecules. Bentonite also increases viscosity for better product spreadability, prevents phase separation in emulsions, opacifies clear formulas for aesthetic appeal, and suspends particles to maintain uniformity, making it ideal for oil-absorbing and texturizing applications in skincare.

Comedogenic Rating 0/5 Low risk of clogging pores
EWG Safety Rating 1-2 View on EWG →
PubChem View on PubChem →

Roles in Formulation

This ingredient serves the following purposes in cosmetic formulations:

Absorbent
Absorbs water and/or sebum to reduce greasiness and shine, improve dry touch, and help keep powders and emulsions feeling lighter on skin.
Bulking agent
Increases mass/volume to build structure and improve handling, commonly used to adjust feel, spread, and cost-in-use without acting as a primary active.
Emulsion stabilizer
Improves emulsion robustness by preventing droplet coalescence and phase separation, often by thickening, structuring, or strengthening the interfacial layer.
Opacifying agent
Makes a formula less transparent to create a creamy, opaque look; can also help visually mask suspended particles and improve aesthetic uniformity.
Suspending agent
Keeps insoluble particles (pigments, beads, actives) evenly dispersed by increasing viscosity or forming a network, preventing settling and separation.
Viscosity controlling agent
Adjusts thickness to the desired level for stability and usability, improving dispensing, suspension, and texture across many formulation types.

Benefits

Absorbs excess sebum to mattify skin and reduce shine.

Supports lightening effects by controlling oil for brighter appearance.

Enhances formula stability and texture for smoother application.

Who It's For

A quick guide for who this ingredient may suit (and who should be cautious).

Who May Benefit Who Should Avoid
Individuals with oily or combination skin seeking oil control.
People with very dry or dehydrated skin prone to tightness.
Those desiring a dry, powdery after-feel in masks or cleansers.
Those experiencing irritation from mineral clays.
Users of purifying products for even suspension of actives.
Individuals in dusty environments where inhalation is a concern.

Safety Notes

  • Considered low hazard with scores of 1-2 from hazard assessments.
  • Safe for cosmetic use as reviewed by expert panels, with non-comedogenic profile.

Frequently Asked Questions about Bentonite

What skin types suit bentonite?

Best for oily or acne-prone skin due to sebum absorption.

Is bentonite non-irritating?

Typically low irritation potential from cosmetic safety reviews.

How does bentonite work in masks?

Swells to draw out impurities and oils for purifying effect.