There’s three types of bentonite clay, with calcium bentonite being the form taken internally by tribes and old civilisations around the world, and potassium bentonite being another type. Sodium bentonite, meanwhile, is the light green or grey, very fine powder which women worldwide use as a face mask to control their acne.
Bentonite clay is derived from the rocks of altered volcanic ash beds. It’s essentially mined from layers of deposits and minerals that build up after countless volcanic eruptions through the ages. The bentonite is born during the rapid cooling of magma when after an eruption, the liquid material is thrown up into the atmosphere from within the earth’s crust. There it solidifies and morphs into solids and glassy particles, and the base of bentonite is born, featuring roughly 75 different trace minerals.
Originally, bentonite was named after Fort Benton in Wyoming when a guy called Wilbur C Knight discovered the largest bentonite mine in the known world in 1898. Since then, bentonite clay has entered a wide variety of usages outside of skincare; the vast majority of commercial production is used for industrial purposes like waterproofing surfaces in construction, oil drilling, well-filling and removing the cloudiness in wine making.
However, at some point bentonite gained massive popularity as a facial mask to kill acne; if you’ve seen or heard of women using grey coloured clay masks, bentonite clay is the most common substance used. The acne cleanser Clearasil contains bentonite as an agent to absorb excess sebum and unclog skin pores, as do a few others.
Common claims of powers include removing toxins through the skin, creating a glow, eliminating acne scars, and dramatically reducing all pimples. Rich in 75 minerals automatically sounds great as well, from zinc, iron and magnesium to rare and little heard of ones like zirconium, ruthenium, and baron.
The whole idea of bentonite clay first forming in the fires of the earth’s crust has an appeal to it. The whole concept of bentonite clay is interesting enough to infer that the reduction in acne could be very interesting as well.
But what does the science say – does bentonite clay have any value as a topical acne treatment or is it just a clever web of marketing deceit?
The main theory is still unproven
The basic theory behind bentonite clay’s powers both for acne and when eaten as a supplement is its detoxification properties. Bentonite clay is said to produce an electrical charge when hydrated. Upon contact with any fluid, the electrical components of the clay change, giving it a strong negative charge.
When it comes into contact with a toxin, which apparently all have strong positive charges, they are attracted like a magnet into the body of the clay through electrical attraction. Then the bonds of the toxin are broken down, releasing the minerals within for the body to use.
According to bentonite folklore, this makes the clay a potent detoxification agent both inside the body and out. One stone-cold undisputed fact about bentonite and other clays is that they swell massively (up to 20 times their normal size) when exposed to water, becoming porous; bentonite is used in construction to seal old wells and ponds for that reason. The theory above also states that through the magnetic attraction, toxins are sucked into this now porous sponge through “adsorption”, becoming bound, trapped and doomed.
Why is this relevant to acne? You might have heard that toxic chemicals and heavy metals in cosmetics and cleaning items (and many other sources) are out of control, and they are. BPA in water pipes, triclosan in toothpaste, mercury in tuna – the list goes on. 99% of all Americans have plastic based chemicals called phthalates in their body, for example.
The disputed part is that these toxins are accumulating rapidly in the skin cells on our face, causing inflammation and oxidative stress that leads to acne. By sucking them out through the skin cells through the force of electrical attraction, bentonite clay can apparently remove their evil influence and make for a highly unique topical treatment.
Finally, the second main theory is that bentonite clay is highly alkaline, and thus soothing and able to wipe out acidity.
Sounds great right? Unfortunately there’s a problem with the evidence for these theories – there’s very little. Heavy metals and chemicals are a massive problem in multiple ways, but their deadliest actions happen inside the body. They can 1) deplete the antioxidant glutathione as they are detoxified, 2) systematically increase inflammation, 3) increase blood free radicals, and 4) do a lot more.
Toxins trapped in the surface of your skin add local inflammation and oxidative stress, but the chances that you will get gloriously clear skin just by “adsorbing” the BPA in your face using bentonite clay are extremely slim.
What’s more, the detoxification has some truth to it – this study and this study found that bentonite clay could absorb and detoxify aflatoxins in the digestive tract, a mould-born mycotoxin found on poor quality peanuts. But it’s unknown whether the negative charge is strong enough to extract virtually every known toxin like the widely accepted facts circulating the internet claim.
All heavy metals are positively charged, like mercury and aluminium, but for the chemicals, the rule isn’t uniform. Phthalates from plastic have a negative charge, and they’re one of the main acne-causing chemicals found in make-up, the main cosmetic applied to the face.
The heavy metal aluminium is found in cheap make-up, so you can use bentonite clay to extract that topically. But mercury, arsenic, and cadmium are found in foods, like for example, tuna, fruit juice, and pesticide-drenched fruit respectively, and won’t be concentrated in the face.
Is bentonite clay soothing and alkaline?
The alkaline theory is another faulty one. A PH of 8-9.7, which is what bentonite clay has, is a disaster for your skin. Human skin has a naturally acidic PH of 4-4.5, increasing slightly as you age into adulthood due to a decreased need for a firewall against viruses.
The thing is that a wide section of alternative health people believe that everything alkaline is evil. There’s a whole acid-alkaline theory of health that believes that nearly every ailment whether it’s cancer, diabetes or Alzheimer’s is related to an excess of acid in the body.
Too much acidity can wreak your teeth and fizzle away your joints, but your skin cells are one place when you need healthy acidity. Applying bentonite clay to your skin would result in dryness, irritation, and in the biggest symptom associated with alkaline treatments like baking soda, severe damage to the skin barrier.
Is bentonite clay the greatest weapon against oily skin ever?
This power is believed to be due to bentonite’s large absorption capacity. When mixed with water and left to expand, and equipped to mingle with the substances on your face thanks to the added moisture, bentonite can literally suck excess sebum off of your face and potentially right out of the pores.
Unlike the toxin theory, this one has evidence going back 30 years. In this 1982 study, scientists wanted to analyse rates of normal sebum production after excess sebum production had been removed. They applied a substance to 2.5cm squared areas of 3 test subjects’ faces for 3 hour intervals over 24 hours. They analysed the sebum in the initial period after the skin was being sucked dry, and later as normal production restarted, but the most important question is, what was the substance used?
Maybe you guessed it – bentonite clay. Clearly, as far back as the 1980s, scientists knew that bentonite clay was a potent weapon against oily skin.
Later this 1985 study on children performed the exact same experiment; bentonite clay was used scientifically to remove the sebum. Bentonite clay wasn’t specifically being examined; it was simply a tool they were using for analysis, so it clearly reduces sebum reliably, and should unclog pores. This ancient volcanic rock formation from inside the earth is highly effective at reducing human oil production.
The problem is that it’s far too effective. Check out these testimonials from random acne patients:
- “I tried it as a face mask and all it did was dry me out”.
- “Bentonite clay dries my face out to the point that it hurts”.
- “Bentonite is extremely drying, more than any topical treatment I have used in my lifetime”.
- “Bentonite sticks to my face really tightly and trying to wash this stuff off is hard”.
- “When I washed the bentonite off, my face was extremely dry”.
There’s positive testimonials as well, with one claiming that bentonite clay had “amazing results”, within weeks, but the story of skin becoming as dry as sandpaper is by far the most common. Not only does that wreck the aesthetics of your skin by sucking the life out of it and producing white flaky patches, but in the long term it could even increase the oiliness of your skin.
Why? Sebum is not some evolutionary leftover which simply exists to clog pores – you need it to lubricate your skin and deliver nutrients. Therefore, if your sebum has been dried up far beyond what is necessary then your sebaceous glands go into overdrive to replenish the lost supplies.
Is bentonite clay rich in skin-clearing minerals?
Then there’s another theory which is accurate but very misleading – the treasure trove of 75 minerals from the earth’s mantle which everyone gets hyped up about. The facts are true, and in descending order, the most abundant minerals are silica, aluminium silica, sodium chloride, potassium, and calcium. There’s tons of rare ones like scandium, cesium, and renium.
But the reality shares similarities to the toxins theory – minerals are far more effective against acne when INSIDE the body. Zinc, for instance, constrains your entire immune system. Magnesium and selenium are used to manufacture glutathione and will have zero benefit when applied to the face.
For instance, there’s a topical cream called selenium sulphide which gets rave reviews, but it’s actually the sulphide portion which helps acne, by massacring p.acnes bacteria. Popular topical zinc creams have been compared to placebos in study and found to be no more effective. Other studies have added zinc to antibiotic creams and observed no difference in results. That’s despite the fact that zinc is an amazing internal supplement that can slash acne counts by 49.8%.
These minerals will have some minor indirect benefits, after all they are essential nutrients contained in all healthy skin, but nothing significant compared to vitamin E or vitamin C.
You’d do better to dunk your head in a giant vat of pomegranate juice, easily, because vitamins and antioxidants are the real heroes when applied topically to the skin. This is because of their antioxidant functioning; your epidermis has armours of both vitamin E and vitamin A to protect against sunlight, air pollution and other free radical sources.
Countless minor antioxidants like resveratrol in grapes and anthocyanins in berries can be incorporated into skin cells in your face, providing extra defences against inflammation and oxidative stress. That’s why my recommended treatments like aloe vera, witch hazel, or even a cheap old orange peel can slash acne.
Therefore, it’s pretty clear that bentonite clay has failed again. Topical minerals are only useful when they’re designed to be absorbed into the entire bloodstream transdermally, like with the ancient minerals magnesium supplement that I recommend.
Bentonite clay has decent antibacterial powers
This study from the Arizona State University tested forms of bentonite clay against a variety of bacteria, including s.aureas, E.coli, m. marianum, and salmonella. They concluded that the bacterial cultures without added clay grew over 1000 times faster, and stated that the bentonite clay “exhibits bactericidal activity”. There was no data on p.acnes bacteria included, but this is promising nevertheless.
Later on there was enough data to make scientists write this long review about the antibacterial effects of bentonite clay, with lots of interesting facts. They began by claiming that “some bentonites offer distinct antibacterial properties”. Then they detailed a study on a French green bentonite clay called a “healing clay” which was able to treat a bacterial skin infection called a Buruli ulcer.
Then things get interesting; clays can either be hydrophilic, meaning that they attract water, or organophillic, meaning that they attract organic substances. The clays tested that were organophillic apparently kill bacteria by attracting the cell to the surface of the clay with such strong force that the cell membrane was torn apart, causing a catastrophic leakage of cytoplasm and then death. Bentonite clay can thus kill bacteria physically, although there was no sign of another physical method examined, orientation of the clay crystals around the bacteria leading to suffocation.
Some chemical bactericide activity was also observed. They theorised that bentonite clay might eliminate bacteria by either 1) poisoning it, or 2) depriving it of nutrients. Interestingly, water or other moisture seems to activate the bacteria-killing properties. Application of dry clay to E. coli showed zero inhibition of bacterial growth, but when the clay was mixed with water, a broad spectrum of bacteria was killed after 24 hours.
What does all this mean? There’s a moderate chance that applying bentonite clay to your face can eliminate p.acnes bacteria in your skin pores, and thus eliminate the need for acne inflammation. This would account for benefits which a few acne patients have seen.
Bentonite clearly has some value, because it shows up in the history books frequently. There’s reports of bentonite clay being found in paint caves from back in the Homo erectus era 1.9 million to 70,000 years ago, and in old Neanderthal man sites, said to have been used for treating wounds. Aboriginal peoples often eat clay for health, and the Pharaoh’s physicians in Ancient Egypt used bentonite clay as an anti-inflammatory agent. The use of clay is as old as mankind itself.
On the other hand, some of the clays tested had no effect at all; they were merely hydrophilic, attracting water. Some of the bentonite clays actually increased bacterial growth, and the problems with drying out your skin still stand. It’s difficult to tell what each individual clay will do, because according to the scientists, bentonites that led to “growth enhancement” were mineralogically similar to the others.
While most of the theories about bentonite clay are false, there is a small chance that covering your face in a mask of it will clear your skin.
Overall, however, using a bentonite clay mask to kill acne is a complete waste of time. Whether it comes from the fires of the earth’s core or not, and whether or not it has some monstrously potent powers against oily skin, this ancient ash deposit still a highly overrated acne treatment.
To treat oily skin you can start with vitamin A and lowering insulin, for a topical treatment against sebum you can use green tea. The antibacterial benefits of bentonite clay are decent, but too weak to counteract the dangers of extreme dryness and alkalinity.
Bentonite clay has a bonus problem as well; the mask often dries and glues to your face so efficiently that removing the clay cleanly is almost impossible, leading to irritation and worse looking skin in the first place. There’s also the sheer inconvenience of it – who wants to walk around all day with a grey or green face mask on?
Raw honey is far simpler, you can apply a tiny amount in five seconds flat and, as long as it’s not an extremely dark coloured variety, walk the streets without looking like an alien. Raw honey also lacks any side effects apart from a small risk of a bee allergy, and the resulting inflammation.
My recommendation is therefore to say no to bentonite clay. If your goal is to remove p.acnes bacteria from your pores with a natural topical treatment, pick raw honey, grapeseed oil, royal jelly, or tea tree oil any time.
Thanks for reading!