If you use activated charcoal on your face, you’ve heard of bentonite clay (also known as calcium bentonite clay). This volcanic ash powder, aged in prehistoric sea beds, is used in hair masks, tonics, and more.
Does it work? History and research are persuasive. This is encouraging, but it doesn’t mean bentonite clay is safe or fulfills all of its health-boosting claims. To clarify, we researched.
What is bentonite?
Ancient volcanic ash exposed to seawater absorbed many minerals to form bentonite clay. The largest bentonite clay deposit is in Fort Benton, Montana, where it’s often mined from ancient seabeds. Montmorillonite clay was first discovered in France’s Montmorillon region.
Smectite clays like bentonite expand when wet. Silica, magnesium, calcium, sodium, copper, iron, and potassium are abundant.
Sodium and calcium bentonite clays differ in mineral ratios. They share subtle traits.
“Both kinds can be used for facial masking,” says Samantha Story of Studio Britta, a holistic skin care clinic in NYC. “Calcium bentonite is gentler and gives the skin more minerals, while sodium bentonite removes more toxins. For facial masks or congested skin, I prefer calcium bentonite.”
Calcium bentonite clay, especially green calcium bentonite clay, is preferred for detoxification because it’s gentler on the body.
The earliest civilizations used clay to treat everything from aches and pains to infections and food poisoning. In ancient Mesopotamia1 (5000 to 3500 BCE), people used clay and water (or other wet ingredients like tea) to make poultices to relieve pain and inflammation.
Bentonite clay has a long history of medicinal use, and anecdotes suggest it’s effective for external and internal use. Is it proven to work?
Despite few human clinical trials, lab and animal research is impressive. However, many of these findings must be validated before being considered recommendations. However, bentonite clay’s most promising benefits include:
It may flush heavy metals.
Bentonite clay’s highly adsorptive nature attracts positively charged particles like a magnet, both topically (hence your face mask’s effectiveness) and internally. Why? Clay particles are negatively charged2. Some research2 suggests that negatively charged bentonite can attach to and remove positive-charged heavy metals and free radicals from the body.
Animal studies support this. Animal feeding studies suggest that bentonite clay may bind aflatoxins and reduce their toxicity. Aflatoxins, produced by fungi on corn, peanuts, cottonseed, and tree nuts, cause cancer. Aflatoxin exposure from contaminated crops increases liver cancer risk.
In one study3, adding bentonite clay to aflatoxin-contaminated corn partially restored pigs’ liver function without affecting their mineral absorption. In another4, rabbits fed an aflatoxin-contaminated diet had improved reproductive function after being fed bentonite.
Heavy metals may be mitigated by bentonite. Arsenic, cadmium, lead, and mercury can cause exhaustion and serious diseases. Cadmium can cause kidney, osteoporosis, and cardiovascular disease.
In one study5, feeding pigs montmorillonite clay (bentonite clay) for 100 days reduced lead levels in their blood, brain, liver, bone, kidneys, and hair. Carp were also exposed to cadmium, which caused oxidative stress, but clay supplementation reversed liver and kidney damage.
Although humans aren’t animals, the fact that bentonite clay removes toxins in various species without affecting mineral absorption is intriguing.
Bentonite is used to treat acid reflux, constipation, bloating, and gas, which makes sense since kaolin, another clay, was used in stomach-soothing medications like Rolaids and Maalox.
Bentonite clay may help IBS patients (IBS). In a small clinical trial7, patients with constipation-predominant IBS who took 3 grams of bentonite clay twice a day for eight weeks had better bowel movements than a placebo group. Pain was unaffected.
Bentonite may reduce IBS by improving gut lining health. Bentonite clay’s anti-parasitic properties may help stomach issues in animals8. Calcium and magnesium in bentonite clay neutralize acid, explaining heartburn relief.
However, bentonite clay consumption remains controversial.
It may fight MRSA.
MRSA, a drug-resistant staph infection, is serious. The CDC9 says it can cause skin, sepsis, pneumonia, and bloodstream infections. Bentonite clay may help where medicine fails.
It calms and protects skin.
Clay has traditionally been used topically to treat bug bites, weird rashes, and infections. Research confirms bentonite’s protective and soothing properties.
When applied to skin before contact with poison ivy’s itch-inducing compound urushiol, a lotion containing bentonite clay prevented or reduced the severity of poison ivy11. Bentonite lotion treated chronic dermatitis12 (irritated and inflamed skin, like eczema).
Bentonite may also treat diaper rash—one study found that it worked faster and better than calendula13. Bentonite improved 88% of skin lesions within six hours, while calendula improved 54%.
These benefits may be due to bentonite clay’s ability to absorb water and draw out skin-irritating substances or to its physical barrier that protects the skin. Bentonite clay minerals may soothe skin.
Skin and hair may improve.
Bentonite beautifies skin and heals rashes. Clay masks are mineral-rich sludge that absorbs oil and clears pores.
Bentonite boosts collagen production and removes dirt, oil, and other skin saboteurs. Bentonite clay applied daily to the skin increased collagen fibers14 in small animals after seven days. Bentonite’s high silica content may help maintain connective tissue. This collagen-boosting benefit hasn’t been proven in humans, but a bentonite face mask is promising.
Bentonite also clears skin. A mask of jojoba oil and bentonite clay applied two or three times a week for six weeks reduced acne lesions by 54% in men and women with mild acne.
Bentonite may even improve hair texture. Bentonite clay hair masks moisturize and draw out dirt and oil, according to many natural beauty bloggers. Bentonite clay is used worldwide to cleanse and soften hair, but there have been no studies.
Bentonite clay for skin, hair, and health.
Bentonite clay has many skin, hair, immune-boosting, and detoxifying uses. We’ve shortened the list for you. Before you start, remember that most brands recommend mixing clay and liquid solutions in a glass or ceramic bowl with a wooden or plastic spoon because metal reacts with clay and reduces its benefits.
Another pro tip: While bentonite clay is sold as a powder, several of the uses below require a paste, so keep a jar on hand. Redmond Clay recommends mixing or shaking 1 part bentonite clay with 2 parts water in a Mason jar.
Our favorite bentonite clay beauty and health uses are:
For minor burns, bug bites, and rashes, mix bentonite clay with water to your desired thickness (usually 1:1 or 2:1) and apply to skin. After drying, wash off the paste.
Armpit detoxes are real. Most conventional deodorants contain aluminum and other ingredients that prevent sweating, which disrupts your body’s natural detox process. However, applying a yogurt-like bentonite clay and water paste to your pits helps pull some of these potentially harmful substances from your skin.
Story says bentonite clay frees the lymphatic system by drawing out heavy metals. “An underarm mask helps lymphatic drainage because armpits have lymph nodes and detoxifying sweat glands. This mask helps restore pH and odor if you’re switching to natural deodorants.”
For extra hydration, Story recommends mixing 1 teaspoon bentonite clay, 1 teaspoon Manuka honey, and enough water to make a paste and applying it to your face. Remove it when it feels tight after 15–20 minutes. After, moisturize and hydrate.
A bentonite hair mask once or twice a week is a natural way to care for oily hair. Many recipes use this combination: Clay, water, and cider vinegar. Apply it from root to tip. Beauty bloggers say it defines curls too.
Skin-softening clay bath
Add 1/4 cup of bentonite powder, 1 cup of Epsom salts, and a few drops of your favorite essential oils to warm bath water for head-to-toe skin soothing. Story says the heat increases circulation and the clay removes toxins. Magnesium in clay and Epsom salts relaxes. Story warns, “These baths can be intense, so make sure to hydrate and listen to your body in terms of how long is right.”
Can’t take a bath? Soak your feet in a bucket of warm water and two tablespoons of bentonite clay. Clay softens feet and relieves soreness due to its magnesium content (just like Epsom salts).
The Dirt? Extra-fine bentonite clay and essential oils flavor this trace mineral tooth-brushing powder. Clay’s abrasive and antibacterial properties may brighten those pearly whites. To DIY, dip your toothbrush in bentonite clay powder and brush. If you have questions, ask your dentist.
Bentonite clay side effects?
Bentonite clay naturally contains lead. While it sounds scary, bentonite clay products sold to consumers are likely too low to cause problems. Due to lead in soil, a 1-teaspoon serving of clay has lower lead levels than sweet potatoes or mixed nuts.
Bentonite clay’s lead is also bonded to other molecules, making it safer than lead paint or contaminated cosmetics. One brand says: “As bentonite clay passes through your body or interacts with your skin, the lead atoms are tightly bound in a matrix with other atoms. These clay molecules’ unusually large surface area and strong negative charge act like magnets to draw positively charged lead out of your body.”
Animal research supports that self-promotional claim. The above pig study5? For 100 days, feeding the pigs montmorillonite clay (bentonite clay) reduced lead in their blood, brain, liver, bone, kidneys, and hair.
In 2016, the U.S. Food & Drug Administration warned consumers17 not to buy Best Bentonite Clay due to elevated lead levels. It’s crucial to buy clay from a reputable brand that has done an elemental analysis to ensure safe lead levels (if you don’t see one on their website, request one).
Bentonite clay can be used topically without risk, but consuming it is still controversial. Stop using if skin irritation occurs.