Bentonite Clay

Medically Reviewed by Jennifer Robinson, MD on September 02, 2022

Bentonite is a very old clay that has been used as a remedy for many things. The fine powder forms when volcanic ash ages. It’s named after Fort Benton, WY, which has a lot of it. But it’s found all over the world. It’s also known as Montmorillonite clay after a region in France with a large deposit. And you may hear it called calcium bentonite clay.

People have eaten bentonite clay or put it on their skin for thousands of years. It’s been used to:

  • Clean or protect skin
  • Heal skin infections or acne
  • Treat stomach gas
  • Ease diarrhea

Today, bentonite is used to make medicine and makeup. You can buy it in powders and pills, too. It’s sometimes used in:

Bentonite clay adsorbs -- it attracts particles, like dirt on your skin. It also absorbs -- it takes in a lot of water. It’s used for face masks, and it’s also what makes pet litter clump.

Bentonite has a high cation exchange capacity. That means clay, which has a negative charge, can attract positively charged ions. Those are minerals like magnesium, sodium, and potassium. Bentonite also has aluminum and silica.

It may also attract positively charged toxins in your gut.

Bentonite clay is antibacterial and anti-inflammatory.

It also has trace minerals like calcium, iron, copper, and zinc. Some people eat it to get these nutrients. That’s called geophagy. But the foods people typically eat already have these minerals.

Most of the research on bentonite clay involves animals. Studies show it may lower the amount of certain toxins in the body, like aflatoxins. They’re made by certain molds and can hurt your liver. Some research shows it may remove pesticides and help treat metal poisoning. But more human studies are needed.

You don’t usually need help to clean out your body. Your kidneys and liver already do that. The fiber from fruits and vegetables also helps.

Uses of bentonite clay

It’s used in many ways, but some show more promise than others.

Skin. Bentonite clay works like a sponge on your skin. It absorbs dirt and oil, like sebum. Too much sebum can lead to acne. The antibacterial and anti-inflammatory properties may help your skin heal.

Studies show bentonite clay may help with:

Talk to your doctor before using the clay if you have acne or dermatitis (eczema). They can help you figure out the best way to treat it.

Hair. Some people use bentonite clay as a hair mask. There are no studies to show whether it’s a good way to clean or soften human hair.

Digestion. Some animal studies show bentonite might boost good bacteria in the gut. This may help with taking in nutrients. In humans, bentonite is sometimes used to treat occasional or ongoing diarrhea. One study showed bentonite helped with constipation from irritable bowel syndrome (IBS). More research is needed.

Teeth. Natural toothpaste makers say the minerals in bentonite clay are good for teeth and gums. Some say brushing with clay can “purify, detoxify, and alkalize” your mouth. There are no scientific studies to back up these claims.

Researchers are also studying the effects of bentonite clay on:

Bentonite clay is generally OK to use on your skin and hair. But the FDA doesn’t regulate health and cosmetic products, so there’s no way to know exactly what’s in them or if they’ll work. If you want to try it, test a little bit of the clay on your skin first to make sure you don’t have a bad reaction.

Doctors don’t recommend eating clay. It could cause a blockage in your intestines. And it can affect how you absorb nutrients and electrolytes. Plus, clay or soil can have high levels of harmful germs and heavy metals like lead, arsenic, and mercury. The FDA has warned against using at least two brands of bentonite clay supplement found to contain lead.

Eating clay can be a sign of pica -- when people or animals eat things that aren’t food. It could mean you’re not getting enough minerals, or you might have a mental disorder.

Talk to your doctor before you take oral bentonite or any supplement, especially if you’re pregnant or take other medicines.

Show Sources


Bethany Doerfler, registered dietitian nutritionist; clinical dietitian, Northwestern Memorial Hospital.

World Health Organization (WHO): “Bentonite, Kaolin, and Selected Clay Minerals.”

International Geology Review: “Evaluation of the medicinal use of clay minerals as antibacterial agents.”

Iranian Journal of Public Health: “Bentonite Clay as a Natural Remedy: A Brief Review.”

Elements: “Bentonite, Bandaids, and Borborygmi.”

National Library of Medicine (TOXNET): “Bentonite.”

Wyoming Mining Association: “Bentonite.”

Cornell University Cooperative Exchange: “Cation Exchange Capacity (CEC).”

Nursing and Midwifery Studies: “Shampoo-Clay Heals Diaper Rash Faster Than Calendula Officinalis.”

Transactions of the Royal Society of Tropical Medicine and Hygiene: “Geophagy and potential health implications: geohelminths, microbes and heavy metals.”

Toxicology Reports: “Heavy metal content and potential health risk of geophagic white clay from the Kumasi Metropolis in Ghana.”

Journal of the American Academy of Dermatology: “Sustainable rates of sebum secretion in acne patients and matched normal control subjects.”

The Journal of the American Dental Association: “Charcoal and charcoal-based dentifrices.”

The American Journal of Tropical Medicine and Hygiene: “Short-Term Safety and Efficacy of Calcium Montmorillonite Clay (UPSN) in Children.”

FDA: “FDA warns consumers about health risks with Alikay Naturals -- Bentonite Me Baby -- Bentonite Clay,” “FDA Warns Consumers Not to Use ‘Best Bentonite Clay.’”

Pediatric Emergency Care: “Severe hypokalemia caused by oral and rectal administration of bentonite in a pediatric patient.”

Journal of International Society of Preventive & Community Dentistry: “Eating everything except food (PICA): A rare case report and review.” “Bentonite.”

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