Quaternium-18 Bentonite

Quaternium-18 Bentonite is a modified clay derived from bentonite, a naturally occurring mineral. It has been chemically treated to make it water-compatible and easier to incorporate into skincare formulations. In cosmetic products, it primarily serves as a viscosity controlling agent, helping to thicken and stabilise creams and lotions.Beyond its formulation role, this ingredient has been studied for its potential to protect the skin barrier, particularly in the context of occupational or contact dermatitis prevention. It is used in a relatively small proportion of skincare products, typic…

Quaternium-18 Bentonite works through its ability to bind to and potentially block irritant and allergenic substances on the skin surface. The clay structure allows it to form a protective film without occluding the skin entirely, which means it can shield against environmental triggers whilst still allowing normal skin function.Within a formulation, its modified bentonite structure helps stabilise the product by controlling viscosity and preventing separation of ingredients, which ensures consistent delivery of other active components.

This ingredient is typically found in protective or barrier-repair creams rather than serums or light moisturisers. Apply to clean, dry skin as part of your regular routine, particularly if you are prone to irritation or contact reactions. Allow a few minutes for the product to set before applying other layers. Consistency of use matters more than frequency; regular application of a Quaternium-18 Bentonite-containing cream is more likely to show benefit than sporadic use.

Quaternium-18 Bentonite is generally well-tolerated and has a long history of use in skincare. Allergic contact dermatitis to the ingredient itself is rare, though as with any product, patch testing is advisable if you have very sensitive skin or known clay sensitivities.