Bentonite

If your skin ever looks in the mirror and says “I need less shine, please,” bentonite is one of those old-school ingredients that often gets called in. This volcanic clay is mostly made of montmorillonite, and its superpower is very simple: it soaks up oil and other gunk like a tiny mineral sponge. That’s why you so often find it in face masks, soaps, and even some spot treatments. When people talk about the benefits of bentonite clay for skin or the benefits of bentonite clay on face, this is usually what they mean: a quick, matte, cleaner-looking finish, especially if your skin is oily or congested.

What makes bentonite a bit more interesting than a generic “mud” is its structure and charge. It can swell in water and has a strong ability to bind to particles, which is why it’s also used in things like bentonite clay mask formulas and bentonite clay in soap. Some lab studies suggest bentonite can bind certain toxins, microbes, and irritating substances, which is probably where its reputation for “detox” comes from. Just keep in mind that detox claims tend to get wildly overenthusiastic. For skin, the evidence is strongest for oil absorption and temporary pore-clearing effects, not magical cleansing of your whole life. And yes, bentonite cat litter uses the same absorbent magic, just hopefully far away from your bathroom shelf.

There’s also some real-world interest in bentonite clay benefits beyond the face. In a bath, it can make water feel silky and may help skin feel less greasy, though a bentonite clay bath is more spa ritual than science-backed detox cure. For hair, it can help remove excess oil and product buildup, which is why bentonite clay for hair has a fan club among people with very limp roots. For teeth, bentonite clay for teeth pops up in “natural” toothpaste recipes, but evidence for whitening or oral health is pretty thin, and abrasive DIY pastes can be a bad idea if you overdo them. The main downside is also very bentonite: it can be drying and a bit stripping, so if you use a bentonite clay face mask or bath, follow up with moisturizer and don’t treat it like a daily necessity. Some sources even list bentonite hills and bentonite hills utah when talking about clay deposits, but your skin only cares that this ingredient is absorbent, inexpensive, and best used with restraint.

When it comes to oil-absorbing clay masks, bentonite will probably be one of the first ingredients on the INCI list. Technically bentonite clay is mostly montmorillonite + something else, and thanks to the something else bit, bentonite comes in different types and colors. 

The color depends on the mineral content of the clay: white bentonite is rich in boron and fluoride, yellow is rich in manganese and zinc, green is rich in copper, zinc, and manganese and the pink clay is rich in boron.

No matter the color, bentonite is excellent at absorbing things: it can suck up the sebum and gunk from the skin and make it instantly smooth and matte. Not only that, but bentonite has a negative ionic charge and thus can attract things with a positive charge. Things with a positive charge include bad bacteria and toxins and bentonite clay masks can help to clear those out of the skin and pores (btw, bentonite is edible and has the same detoxifying effect internally). 

Thanks to bentonite's effect against bad bacteria and pathogens, there is also some research showing that bentonite can help to calm skin infections, soothe skin allergies and might work for skin conditions like psoriasis and eczema.

On the other hand, the downside of bentonite being such a good absorbent is that it can suck up more than the excess sebum and used too often, it can easily dry out the skin. So use it for good measure, and never forget to moisturize afterwards.