Clays & Charcoal · Clay
Bentonite Clay
Bentonite (a clay rock made mostly of montmorillonite, not a plant) · also called Sodium bentonite, calcium bentonite, bentonite clay (shop name), montmorillonite clay
Bentonite is a swelling clay made mostly of montmorillonite and sold as a powder for masks and, by some sellers, to swallow. Swallowing it carries real risks: some oral clays held lead and arsenic, large amounts may cause constipation or blockage, and clay can block medicines. No study shows it detoxes the body. Evidence for skin use is small and early.
General information, not medical advice. Last substantive update · Not medically reviewed. A named clinician has not signed off on this page. How this page is made
About Bentonite Clay
Bentonite is a swelling clay, made mostly of montmorillonite. Swallowing it is the main concern: some oral clays held lead and arsenic, large amounts may cause constipation or blockage, and clay can block medicines such as rifampicin. Skin evidence is limited to two small trials. No study supports detox.
What it is
Bentonite is a clay rock. The papers we read describe it as a natural clay mineral from volcanic ash, with montmorillonite as the main mineral. Calcium bentonite can be treated with sodium to make a sodium bentonite that swells more.
The montmorillonite itself has its own page, and the human mould-toxin trials belong there: they used a refined calcium montmorillonite, not a shop bentonite. Kaolin is a different clay.
Traditional and current uses
Clays have been used on skin and eaten in many places since antiquity. Bentonite has also been used in industry, and now in masks, creams and powders for swallowing.
A case report calls bentonite a homeopathic cathartic, a laxative-type home remedy. Traditional use is not proof it works or is safe.
What the research shows
Skin use has the only human trials. A double-blind trial of 100 infants compared a bentonite cream with calendula cream for diaper rash and found faster and fuller improvement with bentonite, though it had no placebo. A trial of 60 people with moderate acne added a bentonite and plant-extract mask to an antibiotic and found fewer lesions than a placebo mask.
A 2024 review says lab and animal work and early trials are promising and that larger trials are needed.
No trial supports swallowing bentonite for any purpose.
At a glance
Traditional uses history, not proof
- Clays put on the skin for healing and eaten in many places since antiquity (Gomes 2018).
- Used in industry and now in skin care (Zafar 2024).
- Used as a home 'cathartic' remedy for constipation (2006 case report).
Studied for research
- Diaper rash (cream), low (one trial against calendula cream)
- Acne (mask with a plant extract and an antibiotic), very-low
- General skin claims, insufficient
- Skin germs, insufficient (lab and mice)
- Detox or removing heavy metals, insufficient
- Bowel cleanse or constipation, insufficient (a case report of harm)
- Binding mould toxins, insufficient for bentonite
Main compounds
- Montmorillonite (smectite clay mineral)
- Exchangeable sodium or calcium (decides swelling)
- Contaminant metals in some oral clays: lead, arsenic
- Silica in dust
Common forms
- Dry powder
- Mask paste mixed with water
- Creams (one trial)
- Swallowed powders and liquids sold by some sellers (not advised)
Research links: Severe low potassium after bentonite, case report 2006 (abstract) · Lead and arsenic in clays for oral use, Netherlands 2013 (abstract) · Bentonite and rifampicin absorption, 1975 (abstract) · NCCIH: Detoxes and cleanses · Poison Control · Research Library · Genes & Biomarkers Library
What it is and its history
- Accepted scientific name
- Bentonite (an absorbent clay rock made mostly of montmorillonite; not a plant)
- Synonyms
- Sodium bentonite; Calcium bentonite; Bentonite clay (shop name); Montmorillonite-rich clay
- Common names
- Bentonite clay (English); Sodium bentonite (English); Calcium bentonite (English); Arcilla bentonita (Spanish)
- Family or group
- Clay rock rich in montmorillonite, a smectite clay mineral
- Native range
- Mined from deposits in many countries; not checked.
- Harvest and processing
- Dug, then processed. A 2025 study purified and alkali-activated a calcium bentonite with sodium carbonate; a 2026 study sodium-activated an Algerian one. How shop powders are made was not checked.
- Look-alikes and adulterants
- Name: Montmorillonite clay; Note: The main mineral of bentonite. It has its own page; the human mould-toxin trials used a refined calcium montmorillonite, not a shop bentonite.; Name: Kaolin and other clays (illite, green and white clays); Note: Kaolin is a different clay mineral. Colours and names do not tell you the minerals or metals.; Name: Medicine-type smectite (diosmectite); Note: A purified medicine; its results do not transfer to a shop powder.
Traditional use and history history, not clinical proof
| Tradition or era | Documented use | Source |
|---|---|---|
| Ancient to modern | Use of clay for health is described as most probably as old as mankind, with healing clays used for therapy, nutrition and skin care and clay eating seen in all parts of the world since antiquity (Gomes 2018). | p28150053 |
| Industry and skin care | Bentonites and montmorillonites are described as traditionally used in industry and now of interest in dermatology (Zafar 2024). | p39438324 |
| Home remedies | Bentonite is described as having been used as a homeopathic cathartic (a laxative) in a 2006 case report. | p16871112 |
Traditional use shows how it was used. It does not show that it works or is safe today.
What is inside, and how it may work
What it contains and how those compounds act in cells and animals. Laboratory and animal mechanisms are not proven effects in people.
Main compounds
| Compound | Family | Where it is concentrated | Activity studied | Level of evidence |
|---|---|---|---|---|
| Montmorillonite | smectite clay mineral | The predominant mineral in natural and activated bentonite samples tested; percentages were not given in the abstracts. | Layered, swelling clay with a large surface and ion exchange capacity that can hold other substances. 5 4 | Laboratory |
| Exchangeable sodium or calcium | cation in the clay | Sodium activation raised swelling and dispersion (2026 study). | Decides how much the clay swells in water. 4 | Laboratory |
| Contaminant metals (lead, arsenic) in some clays for oral use | contaminants | Up to 99.7 mg/kg lead and 45.1 mg/kg arsenic in oral clays on the Dutch market; bentonite not named. | Toxic if taken in; not part of the clay mineral. 13 | Product analysis |
| Silica dust | airborne particles | Not measured in the abstract. | Bentonite dust may expose workers to silica levels above accepted limits (2019 study). 12 | Occupational |
Mechanisms, receptors and pathways
| Target or pathway | Gene or receptor | What was found | Level |
|---|---|---|---|
| Adsorption of metals | None | Activated Egyptian calcium bentonite took up lead, copper and nickel from water in the lab. A review says clay can also hold heavy metals and make them available for uptake. 5 7 | Laboratory |
| Adsorption of medicines | None | Bentonite adsorbed rifampicin rapidly and strongly and lowered its absorption in six volunteers. 2 | Human pharmacokinetic |
| Binding of skin bacteria | None | Sodium bentonite bound Staphylococcus in culture and prevented lesions when bacteria were pre-treated in mice. The authors say it has no antibacterial or anti-inflammatory action of its own. 9 | Laboratory and mouse |
| Gut binding of electrolytes | None | The case report authors say large amounts of clay can bind essential electrolytes in the gut and may cause blockage. 1 | Case report |
Absorption, metabolism and elimination
- Absorption
- Not studied for shop bentonite in people.
- Distribution
- Not studied.
- Elimination
- Not studied.
- Bioavailability
- Not studied.
Isolated compounds versus whole extracts
Raw, purified and sodium-activated bentonites, calcium and sodium types, refined montmorillonites and medicine smectites are different products. A 2026 study shows sodium activation changes swelling and surface properties.
Nutritional composition
Bentonite is not a food or a nutrient. No study read shows it adds useful minerals to the diet.
1 low certainty1 very low certainty6 not enough evidence
What was looked at
The 8 benefits and uses checked for Bentonite Clay, each with how strong the evidence is. Tap one to open it.
- Diaper rash in infants (bentonite cream)Low certainty
- Acne (bentonite and plant-extract mask with an antibiotic)Very low certainty
- Skin inflammation, wounds, oil and hydration (general claims)Not enough evidence
- Skin germs (Staphylococcus) and skin infectionNot enough evidence
- Detox or removing heavy metals from the bodyNot enough evidence
- A bowel 'cleanse' or help for constipationNot enough evidence
- Gut infection (C. difficile) in a childNot enough evidence
- Binding mould toxins from foodNot enough evidence
Lab markers tracked in the studies
Diaper rash improvementAcne total lesion countAcne Severity IndexPotassium in blood
What is Bentonite Clay good for?
The uses people ask about and how strong the evidence is for each. None of them justifies swallowing bentonite.
Benefits, one by one
Each card is a research question, not a promise. Tap a goal to filter. Open a card to see the studies, doses and limits.
Diaper rash in infants (bentonite cream)
Low certaintyOne double-blind trial in 100 infants compared a bentonite cream with a calendula cream. More babies improved fast and fully with bentonite. The comparison was with another cream, not a placebo, and the cream formula was not described.
1 studiesCream (formula not described). Not advice.
Studies, doses and limits
What the trials found
One randomized double-blind trial, 100 infants, 3 days.
Results
Improvement began within six hours in 88% of infants with bentonite versus 54% with calendula (risk ratio 2.99, P<0.001). Complete improvement within three days: 86% versus 52% (P<0.001).
Effect sizes as reported
Risk ratio 2.99 for early improvement.
Why this rating
One trial, short, against another cream and not a placebo, product contents not described.
Form and dose studied
Cream (formula not described). Not advice.
Who was studied
Infants with diaper dermatitis, mean age about 6 to 7 months.
Limits
No placebo; three days; one site; cream formula unknown.
Why researchers looked
Bentonite is a fine, absorbent clay that is sometimes put on irritated skin.
Traditional use
Clays have been put on skin for healing for a very long time (Gomes 2018).
Proposed mechanism Pharmacological theory
Not established. A review suggests clays may soothe inflammation and absorb moisture, based mostly on lab and animal work.
A proposed mechanism does not show that the effect happens in people.
A baby with a rash that is spreading, weeping or not improving needs a paediatrician. Do not use a loose clay powder near a baby's face, because it can be breathed in.
Acne (bentonite and plant-extract mask with an antibiotic)
Very low certaintyOne small trial added a bentonite-and-Alcea sulphurea mask to an antibiotic for moderate acne and found lower lesion counts than a placebo mask. Because the mask was a mix and everyone also took an antibiotic, bentonite on its own is not tested.
1 studiesFace mask used with azithromycin. Not advice.
Studies, doses and limits
What the trials found
One add-on randomized trial, 60 people, 8 weeks.
Results
At 8 weeks, total lesion count fell by 55.45% and the acne severity index by 66.33% in the mask group, more than with a placebo mask (p<0.001). Satisfaction was higher (43.3% very satisfied versus 3.3%). The authors report no serious side effects.
Effect sizes as reported
See results.
Why this rating
Small, one trial, a combination product on top of an antibiotic, and the abstract mixes up its group names.
Form and dose studied
Face mask used with azithromycin. Not advice.
Who was studied
People with moderate acne, mostly female.
Limits
Not bentonite alone; 60 people; one centre.
Why researchers looked
Clay masks are widely used for oily and acne-prone skin, and bentonite is a traditional ingredient in a Persian-medicine mask.
Traditional use
The mask comes from Traditional Persian Medicine, according to the trial authors.
Proposed mechanism Pharmacological theory
Not established. Clay absorbs oil on the surface; the plant extract is thought to be anti-inflammatory (the authors' view).
A proposed mechanism does not show that the effect happens in people.
Acne that is severe, scarring or painful needs a clinician. Patch-test any new product.
Skin inflammation, wounds, oil and hydration (general claims)
Not enough evidenceA 2024 review says lab experiments, animal studies and early trials suggest bentonite and montmorillonite can calm inflammation, help wounds, absorb oil and improve hydration, and that larger randomized trials are needed to show safety and benefit.
2 studiesNot applicable.
Studies, doses and limits
What the trials found
The review mentions only preliminary clinical trials. No treatment of a skin disease by a plain bentonite mask was found in the sources read apart from the two trials above.
Results
The review gives no numbers in its abstract.
Why this rating
Mostly lab and animal work; the review itself calls for larger trials.
Limits
Mixed clay types and forms; narrative review.
Why researchers looked
Clays are a natural, low-cost skin product with a long history.
Traditional use
Used on the skin for a very long time and still used in industry and cosmetics (Zafar 2024; Gomes 2018).
Proposed mechanism Laboratory
Clay particles are layered, swell in water and hold other substances on their surface.
A proposed mechanism does not show that the effect happens in people.
See the Safety tab for metals in some clays and for breathing dry powder.
Skin germs (Staphylococcus) and skin infection
Not enough evidenceIn lab dishes sodium bentonite bound staphylococcus bacteria, and treated bacteria caused no skin lesions in mice. Put straight on mouse skin as a gel it did little for eczema-like inflammation. No human data.
1 studiesNot applicable.
Studies, doses and limits
Results
Dishes and mice only. Bentonite gel on mouse skin in an atopic dermatitis model reduced ear swelling modestly, but water loss and clinical scores did not change.
Why this rating
Laboratory and mouse results only.
Limits
The protective effect came from treating the bacteria first, which cannot be copied on a person's skin.
Why researchers looked
Clay can stick to bacteria, which suggested it might stop them harming the skin.
Traditional use
Clays have long been put on skin infections (Gomes 2018).
Proposed mechanism Laboratory
Sodium bentonite bound the bacteria and reduced the damage they did to skin cells. The authors say it is not itself antibacterial.
A proposed mechanism does not show that the effect happens in people.
Do not put clay on an infected, open or spreading skin problem without medical advice.
Detox or removing heavy metals from the body
Not enough evidenceNo study shows that swallowing or applying bentonite removes toxins or metals from people. Bentonite holds metals in test-tube water, which is why the claim exists, but that is not a human result.
3 studiesNot applicable.
Studies, doses and limits
What the trials found
No human study of bentonite for detox or metal removal was found in the sources read.
Results
Lab study: activated bentonite took up lead at up to about 13 mg per gram in water. NCCIH reports a 2015 review that found no compelling research that detox diets eliminate toxins from the body (about detoxes in general, not clay).
Why this rating
No human data; lab results do not carry over to the body.
Limits
Absence of evidence; the agency statement is general.
Why researchers looked
Clay holds metals in lab tests, and sellers carry the idea over to the body.
Traditional use
Clay eating has been seen in all parts of the world since antiquity (Gomes 2018).
Proposed mechanism Laboratory
In lab tests, activated Egyptian calcium bentonite took up lead, copper and nickel from water. A review warns clays can also take up heavy metals and make them available for uptake.
A proposed mechanism does not show that the effect happens in people.
Do not swallow clay to detox. Some oral clays held lead and arsenic, and a case report describes severe harm (see the Safety tab).
A bowel 'cleanse' or help for constipation
Not enough evidenceNo trial shows bentonite helps constipation. A case report describes a toddler given bentonite by mouth and rectum for constipation who had dangerously low potassium. Bentonite is a plausible cause of harm here, not a proven help.
1 studiesNot applicable.
Studies, doses and limits
What the trials found
No trial found. One child case report of harm.
Results
A 3-year-old had blood potassium of 0.9 mmol/L with ECG changes after bentonite was given by mouth and rectum. She recovered with fluids and potassium replacement.
Why this rating
No trial of benefit; one case report of harm.
Who was studied
One child.
Limits
One case; she was constipated before, so cause and effect cannot be separated.
Why researchers looked
Bentonite has been used as a home or homeopathic cathartic (case report authors).
Traditional use
Used in home remedies for constipation (as described in the case report).
Proposed mechanism Case report
The case report authors say large amounts of clay can bind essential electrolytes in the gut and may cause blockage.
A proposed mechanism does not show that the effect happens in people.
Do not give bentonite to a child or an adult to treat constipation. Lasting constipation, vomiting or weakness needs a doctor.
Gut infection (C. difficile) in a child
Not enough evidenceOne case report of a 2-year-old whose C. difficile test turned negative after four days of black seed oil, bentonite and probiotics together. It cannot show that bentonite or any one of the three did anything.
1 studiesNot applicable.
Studies, doses and limits
What the trials found
A single case report, three products at once.
Results
No C. difficile on a stool test after four days.
Why this rating
One uncontrolled case with three products.
Who was studied
One 2-year-old.
Limits
No comparison; the infection may settle without the products; the authors call for research.
Why researchers looked
A family and its clinicians chose a natural plan after antibiotics.
Traditional use
Not a traditional use.
Proposed mechanism Unknown
Not established.
A proposed mechanism does not show that the effect happens in people.
A young child with diarrhoea after antibiotics needs a doctor, not a home remedy. Clay by mouth is risky for children (see the Safety tab).
Binding mould toxins from food
Not enough evidenceThe human trials on mould toxins used a refined calcium montmorillonite made for research, not a shop bentonite. No trial of ordinary bentonite for this was found in the sources read. See the Montmorillonite clay page for those trials.
1 studiesNot applicable.
Studies, doses and limits
Why this rating
No human trial of bentonite itself in the sources read.
Limits
The refined montmorillonite trials cannot be applied to a shop product.
Why researchers looked
Bentonite is used as a feed additive to bind mould toxins in animals.
Traditional use
Not a traditional use.
Proposed mechanism Laboratory
Clay particles can hold toxins in the gut so less is absorbed (laboratory and animal work).
A proposed mechanism does not show that the effect happens in people.
Mould toxins are best avoided by storing grain and nuts well.
Connections to the rest of health
How Bentonite Clay connects to the rest of our health knowledge graph. Every link says what kind of connection it is. A safety link (for example to the liver) is a warning, not a benefit. A study that merely mentions a topic never creates a benefit link.
Explore every connection: goals, body systems, organs, symptoms, genes
A. Wellness goals
| Connected to | Kind of connection | Evidence status | Context | Studies |
|---|---|---|---|---|
| Skin Health | Low certainty | Diaper rash in infants (bentonite cream): One double-blind trial in 100 infants compared a bentonite cream with a calendula cream. More babies improved fast and fully with bentonite. The comparison was with another cream, not a placebo, and the cream formula was not described. | 11 | |
| Skin Health | Very low certainty | Acne (bentonite and plant-extract mask with an antibiotic): One small trial added a bentonite-and-Alcea sulphurea mask to an antibiotic for moderate acne and found lower lesion counts than a placebo mask. Because the mask was a mix and everyone also took an antibiotic, bentonite on its own is not tested. | 14 | |
| Skin Health | Not enough evidence | Skin inflammation, wounds, oil and hydration (general claims): A 2024 review says lab experiments, animal studies and early trials suggest bentonite and montmorillonite can calm inflammation, help wounds, absorb oil and improve hydration, and that larger randomized trials are needed to show safety and benefit. | 15 4 | |
| Wound Healing | Not enough evidence | Skin inflammation, wounds, oil and hydration (general claims): A 2024 review says lab experiments, animal studies and early trials suggest bentonite and montmorillonite can calm inflammation, help wounds, absorb oil and improve hydration, and that larger randomized trials are needed to show safety and benefit. | 15 4 | |
| Skin Health | Not enough evidence | Skin germs (Staphylococcus) and skin infection: In lab dishes sodium bentonite bound staphylococcus bacteria, and treated bacteria caused no skin lesions in mice. Put straight on mouse skin as a gel it did little for eczema-like inflammation. No human data. | 9 | |
| Detoxification Support | Not enough evidence | Detox or removing heavy metals from the body: No study shows that swallowing or applying bentonite removes toxins or metals from people. Bentonite holds metals in test-tube water, which is why the claim exists, but that is not a human result. | 5 7 16 | |
| Digestive Health | Not enough evidence | A bowel 'cleanse' or help for constipation: No trial shows bentonite helps constipation. A case report describes a toddler given bentonite by mouth and rectum for constipation who had dangerously low potassium. Bentonite is a plausible cause of harm here, not a proven help. | 1 | |
| Digestive Health | Not enough evidence | Gut infection (C. difficile) in a child: One case report of a 2-year-old whose C. difficile test turned negative after four days of black seed oil, bentonite and probiotics together. It cannot show that bentonite or any one of the three did anything. | 10 | |
| Digestive Support | Not enough evidence | Binding mould toxins from food: The human trials on mould toxins used a refined calcium montmorillonite made for research, not a shop bentonite. No trial of ordinary bentonite for this was found in the sources read. See the Montmorillonite clay page for those trials. | 7 |
B. Body systems
| Connected to | Kind of connection | Evidence status | Context | Studies |
|---|---|---|---|---|
| Integumentary System | Biological association | Low certainty | Studied for: Diaper rash in infants (bentonite cream) Studied for: Acne (bentonite and plant-extract mask with an antibiotic) | 11 14 15 4 9 |
| Immune System | Biological association | Not enough evidence | Studied for: Skin germs (Staphylococcus) and skin infection Studied for: Gut infection (C. difficile) in a child | 9 10 |
| Digestive System | Biological association | Not enough evidence | Studied for: Detox or removing heavy metals from the body Studied for: A bowel 'cleanse' or help for constipation | 5 7 16 1 10 |
I. Biomarkers
| Connected to | Kind of connection | Evidence status | Context | Studies |
|---|---|---|---|---|
| Diaper rash improvement | Biological association | Low certainty | Measured in trials: improved. A lab change is not the same as a health benefit. | 11 |
| Acne total lesion count | Biological association | Very low certainty | Measured in trials: lowered. A lab change is not the same as a health benefit. | 14 |
| Acne Severity Index | Biological association | Very low certainty | Measured in trials: lowered. A lab change is not the same as a health benefit. | 14 |
| Potassium in blood | Biological association | Very low certainty | Measured in trials: lowered. A lab change is not the same as a health benefit. | 1 |
L. Active compounds
| Connected to | Kind of connection | Evidence status | Context | Studies |
|---|---|---|---|---|
| Montmorillonite | Biological association | Laboratory | Layered, swelling clay with a large surface and ion exchange capacity that can hold other substances. | 5 4 |
| Exchangeable sodium or calcium | Biological association | Laboratory | Decides how much the clay swells in water. | 4 |
| Contaminant metals (lead, arsenic) in some clays for oral use | Biological association | Product analysis | Toxic if taken in; not part of the clay mineral. | 13 |
| Silica dust | Biological association | Occupational | Bentonite dust may expose workers to silica levels above accepted limits (2019 study). | 12 |
Each connection is stored with the ingredient, the connected record, the kind of connection, the evidence status, the supporting studies, the preparation or compound involved, and a review date (last reviewed October 30, 2026).
Evidence at a glance: what changed in 3 lab markers
Tap a number to show only those markers. Counts are markers, not people.
The evidence
The research centre for Bentonite Clay. Every record here was checked against PubMed or the publisher's page; we never list a study we have not verified.
Evidence by outcome
Bars show how many studies we found for each outcome, not how well it works. People are added up across trials only (reviews are not added, to avoid double counting).
How we rate evidence
High certainty
Several well-run trials or reviews agree; further research is unlikely to change the picture much.
Moderate certainty
Good trials point the same way, but some doubt remains.
Low certainty
Small, short or inconsistent trials. The finding could change with better research.
Very low certainty
Very little or very weak human data. Treat as a possibility only.
Mixed findings
Trials or reviews disagree with each other.
Not enough evidence
Not enough human research to say either way.
Evidence against
Good research found no benefit, or found harm.
We take the reviewers' own risk-of-bias and GRADE statements where they exist, and otherwise judge from study size, design, consistency, directness and whether a product matches what is sold. Many publications do not make evidence high. Method note: We searched PubMed, read the abstract of each cited paper, and read the FDA cosmetics, NCCIH detox and Poison Control pages. Certainty ratings are the compiler's own reading. Regulators outside the US were not checked. No study is cited that we could not verify.
Study library: every study we checked 18
| Study | Design | People | Product, dose, length | Result |
|---|---|---|---|---|
| Bennett 2006 Severe hypokalemia caused by oral and rectal administration of bentonite in a pediatric patient. Pediatric Emergency Care · PMID 16871112 · DOI |
Case report human (child) |
1 A 3-year-old girl |
Home remedy containing colloidal bentonite by mouth and by rectum, given for persistent constipation mineral clay (not a plant) |
She had vomiting, constipation, lethargy and weakness. Blood potassium was 0.9 mmol/L with ECG changes of low potassium. She recovered with fluids, antibiotics and potassium given into a vein. The authors say large amounts of bentonite by mouth have the potential to cause bowel obstruction and electrolyte problems, and that symptoms resolved with potassium replacement and stopping bentonite. Methods, limits and fundingOutcomes: Blood potassium and symptoms Limitations: One case. The child was already constipated, so cause and effect cannot be separated. The rectal route is unusual. Shows a possible harm, not how common it is. Funding and conflicts: Not stated in the abstract. Read: abstract |
| Boman 1975 Mechanism of the inhibitory effect of PAS granules on the absorption of rifampicin: adsorption of rifampicin by an excipient, bentonite. European Journal of Clinical Pharmacology · PMID 1233228 · DOI |
Human pharmacokinetic study |
6 Six healthy volunteers |
Rifampicin solution taken with PAS granules, whose main filler (excipient) was bentonite mineral clay (not a plant) Single occasion · vs Rifampicin alone; tablets without bentonite |
PAS granules lowered absorption of rifampicin; dummy granules with the same fillers but no PAS did the same, and PAS tablets did not. In the lab, bentonite adsorbed rifampicin rapidly and strongly. Methods, limits and fundingOutcomes: Absorption of the antibiotic rifampicin Limitations: Small 1975 study of a medicine granule, not a clay supplement. It shows the effect can happen, not its size for a shop powder. Funding and conflicts: Not stated in the abstract. Read: abstract |
| Bonglaisin 2022 Geophagia: Benefits and potential toxicity to human-A review. Frontiers in Public Health · PMID 35958861 · DOI |
Narrative review review |
People who eat clay soil, chalk or kaolin | Eaten clays (geophagy) mineral clay (not a plant) |
Says the safety of eating clay is not fully established, that it is thought to be common in pregnant women, that clay composition varies from place to place, that some minerals found in eaten clays are toxic if swallowed, and that studies of toxicity are lacking. Methods, limits and fundingOutcomes: Benefits and toxicity of eating clay Limitations: About eaten clays in general, mostly kaolin and chalk, not bentonite. Read as abstract. Funding and conflicts: No conflict statement in the abstract. Read: abstract |
| Chebani 2026 Sodium-activated Algerian bentonite with improved surface properties and topical barrier performance. Journal of Pharmaceutical Sciences · PMID 41687876 · DOI |
Laboratory and animal study animal (species not named in the abstract) |
A purified, sodium-activated clay made from an Algerian calcium bentonite, tested in animals | Sodium-activated bentonite dispersions (2 to 10% w/v) on the skin mineral clay (not a plant) |
Sodium activation of a calcium bentonite gave a clay rich in montmorillonite with more surface area and ion exchange capacity, which the authors link to more swelling. In an animal model, 2 to 10% dispersions were well tolerated in an acute skin toxicity study and reduced irritant-induced ear swelling, in the same order as indomethacin. Methods, limits and fundingOutcomes: Clay properties, dermal toxicity, ear swelling after an irritant Limitations: Animal model of an irritant, not eczema or any human skin disease. A purified lab product, not a shop powder. Funding and conflicts: Not stated in the abstract. Read: abstract |
| Eleraky 2025 Adsorptive removal of lead, copper, and nickel using natural and activated Egyptian calcium bentonite clay. Scientific Reports · PMID 40240407 · DOI |
Laboratory study laboratory |
Synthetic wastewater, not a person | Natural and alkali-activated Egyptian calcium bentonite (montmorillonite was the main mineral) mineral clay (not a plant) 1 g per litre in the test 120 minutes · vs Natural versus activated bentonite |
Activated bentonite took up lead at up to about 13 mg per gram, copper 14 and nickel 12.2, more than the natural clay (about 9, 9.2 and 8). Montmorillonite was the main mineral in both. Methods, limits and fundingOutcomes: Metal uptake by the clay in water Limitations: Test tube work in water at set conditions. It shows clay can hold metals. It does not show it removes them from a person. Funding and conflicts: Not stated in the abstract. Read: abstract |
| Elmore AR (Cosmetic Ingredient Review panel) 2003 Final report on the safety assessment of aluminum silicate, calcium silicate, magnesium aluminum silicate, magnesium silicate, magnesium trisilicate, sodium magnesium silicate, zirconium silicate, attapulgite, bentonite, Fuller's earth, hectorite, kaolin, lithium magnesium silicate, lithium magnesium sodium silicate, montmorillonite, pyrophyllite, and zeolite. International Journal of Toxicology · PMID 12851164 |
Safety assessment (expert panel review) review (animal and workers) |
Clay-like silicates used in cosmetics | n/a |
Says these ingredients contain silicon, oxygen and one or more metals and are not significantly toxic in short-term oral studies in animals, but that inhalation toxicity is readily shown in animals. Fibrosis and pneumoconiosis are documented in workers who mine and process some of these minerals, including montmorillonite and Fuller's earth. The panel found them safe as currently used in cosmetics, and said any spray containing these solids should be formulated to minimise inhalation. Bentonite injected into rabbit eyes caused severe iritis. Methods, limits and fundingOutcomes: Safety as used in cosmetics Limitations: 2003 review that groups many minerals. Cosmetic use only, not swallowing. Read as abstract (Suppl 1, vol 22). Funding and conflicts: Industry-funded expert panel (Cosmetic Ingredient Review); funding not stated in the abstract. Read: abstract |
| Gomes 2018 Healing and edible clays: a review of basic concepts, benefits and risks. Environmental Geochemistry and Health · PMID 28150053 · DOI |
Narrative review review |
Healing and edible clays in general | Healing and edible clays mineral clay (not a plant) |
Says clay particles could adsorb toxins so they can be eliminated, but could also adsorb heavy metals and make them available for uptake through eating or the skin. Says healing clays have been used for therapy, nutrition and skin care, and that clay eating has been seen in all parts of the world since antiquity. Methods, limits and fundingOutcomes: Benefits and risks of healing clays Limitations: Covers clays in general, not bentonite alone. Read as abstract. Funding and conflicts: No conflict statement in the abstract. Read: abstract |
| Hornfeldt 1996 Suspected bentonite toxicosis in a cat from ingestion of clay cat litter. Veterinary and Human Toxicology · PMID 8888544 |
Veterinary case report cat |
1 A 2.5-year-old cat |
Bentonite-containing clay cat litter, swallowed mineral clay (not a plant) |
The cat had low potassium and severe anaemia, recovered with fluids, electrolytes and a blood transfusion, and the signs returned after the litter was used again. The authors suggest bentonite toxicosis and say the signs resemble those reported in people who chronically swallowed bentonite clays. Methods, limits and fundingOutcomes: Blood potassium and red cells Limitations: One cat; cause suggested, not proven. Animal evidence only. Funding and conflicts: Not stated in the abstract. Read: abstract |
| Kaneki 2026 Preventive effect of bentonite against pyoderma via direct binding capability of staphylococci. PLoS One · PMID 41576001 · DOI |
Laboratory and mouse study mouse / in vitro |
Staphylococcus cultures, skin cells and mice | Sodium bentonite (gel and pre-treatment of bacteria) mineral clay (not a plant) |
Sodium bentonite bound staphylococci in culture and reduced viable counts. Mice given bacteria that had been pre-treated with bentonite did not develop lesions. Bentonite gel put directly on mouse skin in an atopic dermatitis model gave only modest benefit: ear swelling fell but water loss and clinical scores did not change. The authors say bentonite is not itself antibacterial or anti-inflammatory. Methods, limits and fundingOutcomes: Bacterial counts, skin cell injury, inflammation markers, mouse skin lesions Limitations: Laboratory and mouse work only. The protective effect came from treating the bacteria first, not from treating a skin problem. Funding and conflicts: Not stated in the abstract. Read: abstract |
| Littman 2022 Black Seed Oil, Bentonite Clay, and Probiotics: A Comprehensive Holistic Cure for Clostridium difficile Infection in a 2-Year-Old Female Child. Case Reports in Infectious Diseases · PMID 35677311 · DOI |
Case report human (child) |
1 A 2-year-old with C. difficile gut infection after antibiotics |
Black seed oil, bentonite clay and probiotics together mineral clay (not a plant) |
No C. difficile was found on a stool test after four days of the three products together. Methods, limits and fundingOutcomes: Stool test for C. difficile Limitations: One child, three products at once, no comparison group. It cannot show which product did what, or that any of them worked. The title calls it a cure, which one case cannot show. Infection in a child needs a doctor. Funding and conflicts: Not stated in the abstract. Read: abstract |
| Mahmoudi 2015 Comparing the effects of Bentonite & Calendula on the improvement of infantile diaper dermatitis: A randomized controlled trial. Indian Journal of Medical Research · PMID 26831423 · DOI |
Randomized controlled trial (double blind, active comparator) human (infants) |
100 Infants with diaper dermatitis (mean age about 6 to 7 months) |
Bentonite cream applied to the skin (contents of the cream not described in the abstract) mineral clay (not a plant) 3 days · vs Calendula cream |
88% of lesions in the bentonite group began improving within six hours versus 54% with calendula (P<0.001); risk ratio 2.99. Complete improvement within three days in 86% of infants with bentonite versus 52% with calendula (P<0.001). Risk ratio 2.99 for improvement within six hours Methods, limits and fundingOutcomes: Speed and completeness of improvement of diaper rash Limitations: The comparison was with another cream, not a placebo, so it cannot show bentonite beats no treatment. Three days of follow-up. The abstract does not describe the cream formula. One trial. Funding and conflicts: Research support, non-US government (abstract); no conflict statement in the abstract. Registration: IRCT2012112811593N1 Read: abstract |
| O'Neill 2019 Does exposure to bentonite dust during tunnel hyperbaric interventions increase health risks for compressed air workers? A prospective qualitative and quantitative safety assessment. Undersea & Hyperbaric Medicine · PMID 31509901 |
Observational exposure assessment human (workers) |
Tunnel compressed-air workers | Airborne bentonite dust at work mineral clay (not a plant) |
Concluded that bentonite dust may be an emerging particle concern for these workers, that aerosolized bentonite may cause pneumoconiosis and silicosis, and that respiratory silica levels may exceed accepted industrial limits. Methods, limits and fundingOutcomes: Dust and silica exposure Limitations: Industrial tunnel work, not home or cosmetic use. The abstract gives no numbers. A comment was published on it. Read as abstract. Funding and conflicts: Not stated in the abstract. Read: abstract |
| Reeuwijk 2013 Levels of lead, arsenic, mercury and cadmium in clays for oral use on the Dutch market and estimation of associated risks. Food Additives & Contaminants Part A · PMID 23862762 · DOI |
Product analysis with risk estimate product analysis |
63 63 clays for oral use sold in the Netherlands: 10 traditional African, 26 Surinamese, 27 health clays |
n/a |
Maximum lead 99.7, arsenic 45.1, mercury 2.2 and cadmium 0.75 mg per kg. Use of 34 of 36 traditional clays and 2 of 27 health clays would exceed the lead limit, by up to 20-fold. Use of 15 of 35 traditional clays and 11 of 27 health clays would exceed the inorganic arsenic limit, by up to 19-fold. The authors say limited bioaccessibility may reduce exposure, but that intakes from some clays could be of concern, especially for pregnant women, and that use should be discouraged. Methods, limits and fundingOutcomes: Lead, arsenic, mercury and cadmium content and estimated intake Limitations: The abstract does not say which of the clays were bentonite. Intakes are estimates. Clays from 2004 to 2012. Funding and conflicts: Not stated in the abstract. Read: abstract |
| Salimi 2025 The Therapeutic Effects of a Bentonite-Based Facial Mask With Alcea sulphurea Extract on Acne Severity and Patient Experience: Add-On Randomized Controlled Clinical Trial. Journal of Cosmetic Dermatology · PMID 41347526 · DOI |
Randomized controlled trial (add on, placebo controlled) |
60 People with moderate acne (76.7% female) |
Facial mask of bentonite plus Alcea sulphurea extract, with azithromycin 250 mg mineral clay (not a plant) 8 weeks · vs Placebo mask plus azithromycin |
Mask group had lower total lesion count and acne severity at 4 and 8 weeks (p<0.001). From baseline to 8 weeks, lesion count fell by 55.45% and severity index by 66.33% in the mask group. Very satisfied: 43.3% versus 3.3%. The authors report no serious side effects. Methods, limits and fundingOutcomes: Acne lesion count, acne severity index, satisfaction Limitations: A mix of bentonite and a plant extract on top of an antibiotic, so the effect of bentonite alone cannot be told. 60 people. The abstract mixes up the names of the two groups in one sentence. One trial. Funding and conflicts: Not stated in the abstract. Registration: IRCT20220403054395N1 Read: abstract |
| Zafar 2024 The potential cutaneous benefits of bentonites and montmorillonites. Archives of Dermatological Research · PMID 39438324 · DOI |
Narrative review review |
Bentonites and montmorillonites in skin care | Bentonite and montmorillonite clays mineral clay (not a plant) |
Describes clays as natural minerals from volcanic ash. Says evidence from in vitro experiments, animal studies and preliminary clinical trials suggests they can reduce inflammation, speed wound healing, absorb oil, help drug delivery, protect from UV and improve skin hydration and elasticity. Says larger randomized trials are needed to establish safety and efficacy. Methods, limits and fundingOutcomes: Skin effects: inflammation, wound healing, oil absorption, drug delivery, sun protection, ageing Limitations: A narrative review of mixed clay types. It reports preliminary evidence, and the abstract gives no numbers. Read as abstract. Funding and conflicts: Not stated in the abstract. Read: abstract |
| n/a 2025 NCCIH (NIH): Detoxes and Cleanses: What You Need To Know (last updated March 2025) n/a · Source |
Authoritative guidance n/a |
n/a | n/a |
Says a 2015 review concluded there was no compelling research to support "detox" diets for weight management or for eliminating toxins from the body. Methods, limits and fundingOutcomes: Whether detox products and diets remove toxins Limitations: A health agency page about detoxes in general; it does not mention clay. Page read 2026-10-30. Read: full-text |
| n/a 2025 US FDA: FDA Authority Over Cosmetics: How Cosmetics Are Not FDA-Approved, but Are FDA-Regulated n/a · Source |
Authoritative guidance n/a |
n/a | n/a |
Says that under the law cosmetic products and ingredients do not need FDA premarket approval, with the exception of colour additives, and that FDA can take action against products on the market that do not comply with the law. Methods, limits and fundingOutcomes: How cosmetics are regulated in the United States Limitations: Does not mention clay. Page read 2026-10-30. Read: full-text |
| n/a 2026 Poison Control (America's Poison Centers): home page n/a · Source |
Authoritative guidance n/a |
n/a | n/a |
Says to use the web POISON CONTROL online tool or call 1-800-222-1222, free and confidential, and to call 911 if the person collapses, has a seizure, has trouble breathing or cannot be woken. Methods, limits and fundingOutcomes: What to do after a poisoning Limitations: General poisoning advice; it does not mention clay. Page read 2026-10-30. Read: full-text |
What we do not know yet
- No trial of bentonite by mouth for any purpose.
- No trial of plain bentonite alone for acne or any skin disease.
- No measured lead or aluminium in shop bentonite taken by mouth.
- No data on pregnancy, breastfeeding or kidney disease with bentonite.
How new research is added
New studies are found by a saved PubMed search and are placed in a review queue. A person reads each one before it changes any evidence rating or safety wording.
Lab markers
What changed in blood or saliva tests during trials. A changed number is not the same as feeling or being healthier, and we give no "normal ranges".
Other 4
Diaper rash improvement
Improved in trials
Whether the red, sore area was getting better, judged by looking at it.
Low certaintyResults and what it means
Why it was measured
To compare how quickly the rash settled.
Statistical vs. clinical meaning
One trial against another cream, no placebo.
Safety implication
Not stated in the abstract.
| Study | Result | People | Product |
|---|---|---|---|
| 11 | Early improvement 88% versus 54% with calendula cream; complete improvement by day three 86% versus 52% (both P<0.001). | 100 infants | Bentonite cream vs calendula cream |
Acne total lesion count
Lowered in trials
The number of acne spots counted by an examiner.
Very low certaintyResults and what it means
Why it was measured
To see whether the mask reduced spots.
Statistical vs. clinical meaning
A combination product on top of an antibiotic; one small trial.
Safety implication
Authors report no serious side effects.
| Study | Result | People | Product |
|---|---|---|---|
| 14 | Fell by 55.45% from baseline to 8 weeks with the bentonite and Alcea sulphurea mask, more than with placebo mask (p<0.001). | 60 people with moderate acne | Bentonite and Alcea sulphurea mask plus azithromycin vs placebo plus azithromycin |
Acne Severity Index
Lowered in trials
A score of how bad the acne is overall.
Very low certaintyResults and what it means
Why it was measured
To see whether the mask changed how severe the acne was.
Statistical vs. clinical meaning
Same limits as above.
Safety implication
Not stated beyond no serious side effects.
| Study | Result | People | Product |
|---|---|---|---|
| 14 | Fell by 66.33% from baseline to 8 weeks with the mask (p<0.001 versus placebo). | 60 people with moderate acne | Bentonite and Alcea sulphurea mask plus azithromycin |
Potassium in blood
Lowered in trials
The amount of potassium in the blood, which the heart and muscles need to work.
Very low certaintyResults and what it means
Why it was measured
A very low level can cause weakness and dangerous heart rhythm changes.
Statistical vs. clinical meaning
One case; shows a possible harm, not how often it happens.
Safety implication
Severe low potassium is an emergency.
| Study | Result | People | Product |
|---|---|---|---|
| 1 | 0.9 mmol/L with ECG changes in a child given bentonite by mouth and rectum; normalised with potassium replacement. | One 3-year-old | Home remedy containing colloidal bentonite |
Safety
What studies and official sources say about side effects, medicines and who should check first. Each point shows what kind of evidence it comes from.
Main points to know 5
- Do not swallow bentonite as a detox or cleanse. No study shows it detoxes the body. A published case report describes a 3-year-old with severely low blood potassium after bentonite was given by mouth and rectum. The authors say large amounts by mouth have the potential to cause bowel obstruction and electrolyte problems. Case report 1 16
- Some clays for oral use held lead and arsenic. A Dutch study of 63 clays for oral use found up to 99.7 mg/kg lead and 45.1 mg/kg arsenic. Intake estimates for 2 of 27 health clays exceeded the lead limit and for 11 of 27 exceeded the inorganic arsenic limit, by up to 19-fold. The abstract does not say which clays were bentonite. We found no measured lead data for shop bentonite and no measured aluminium data. Product analysis 13
- Constipation and blockage. Swallowed clay in large amounts may cause constipation or bowel blockage, according to the case report authors. The child in that report was already constipated, so one case cannot show how often it happens. Do not use bentonite for constipation. Case report 1
- It can block medicines. Bentonite adsorbed the antibiotic rifampicin rapidly and strongly and lowered its absorption in six volunteers. If you take any medicine, ask a pharmacist before swallowing clay. Human pk study 2
- Avoid breathing the dry powder. Fibrosis and pneumoconiosis are documented in workers who mine and process some clay minerals, and a 2019 tunnel-worker study says bentonite dust may expose workers to silica above accepted limits. Home use is far lower, but mix powder carefully and keep it away from babies' faces. Occupational and review 6 12
Side effects 5
| Effect | How often | Severity and recovery | Evidence |
|---|---|---|---|
| Severely low blood potassium, vomiting, weakness, lethargy Bentonite was given by mouth and by rectum as a constipation remedy. | One child case report; no rate | severe Resolved with potassium replacement and stopping bentonite | Case report 1 |
| Bowel obstruction or constipation from large amounts swallowed Stated by the authors as a potential, not shown in a trial. | Not measured; described as a potential in the case report | potentially severe Not stated | Case report 1 |
| Low potassium and anaemia in a cat that swallowed bentonite cat litter Animal case, suggests keep pets away from clay. | One cat; signs returned when the litter was used again | severe Recovered with fluids, electrolytes and a transfusion | Animal case report 8 |
| Skin reactions with masks and creams Two small trials; not a safety study. | No serious side effects reported in the acne mask trial; the diaper trial abstract does not report side effects | not reported Not stated | Clinical trial 14 11 |
| Lung disease from breathing dust (workers) Workplace exposure to mined clays, not cosmetic use. | Not measured for home use | serious in occupational exposure Not stated | Occupational 6 12 |
Liver
No liver injury report for bentonite was found in the sources read. Not searched in LiverTox.
How often. No rate. Not searched in LiverTox.
Monitoring. No monitoring advice was found.
This is a safety connection. It is not evidence that Bentonite Clay supports liver health.
Medicines and supplements 3
| With | Why it matters | Importance | Evidence | What to do |
|---|---|---|---|---|
| Rifampicin (antibiotic) prescription | Bentonite adsorbed rifampicin rapidly and strongly, lowering how much was absorbed. | Six healthy volunteers, 1975; the bentonite came from a medicine granule filler, not a clay supplement. It shows the effect can occur, not how large it is for a shop powder. | Human pk study Low certainty 2 | Ask a pharmacist before taking clay if you use rifampicin or any medicine. |
| Other medicines and supplements taken by mouth prescription | Clay can hold other substances on its surface, which could lower how much of a medicine or vitamin is absorbed if swallowed together. | No study of a bentonite supplement with other medicines was found. A review says clay particles can adsorb substances, which is theory here. | Pharmacological theory Not enough evidence 7 | Ask a pharmacist before swallowing clay near medicine times. |
| Medicines or conditions that lower blood potassium (for example some water tablets, vomiting or diarrhoea) prescription | Bentonite was linked to low blood potassium in one case report. Whether it adds to these other causes is not known. | No study; shown only to flag a gap. | Gap Not enough evidence 1 | Ask a clinician before swallowing bentonite if you take water tablets or have vomiting or diarrhoea. |
Who should check first 6
| Situation | Advice | Evidence |
|---|---|---|
| Pregnancy and breastfeeding | The Dutch study says lead and arsenic intakes from some oral clays could be of concern and that use, especially by pregnant women, should be discouraged. A review says the safety of eating clay is not fully established. No data on bentonite in breastfeeding were found. Do not swallow clay without a clinician's advice. | Product analysis 13 3 |
| Babies and children | A 3-year-old had severe low potassium after bentonite by mouth and rectum. Keep clay powders out of children's reach. A cream was used in a trial on infants with diaper rash, but that does not make a loose powder safe; ask a paediatrician. | Case report 1 11 |
| Constipation, bowel problems or a history of blockage | Do not swallow bentonite. It may bind gut contents and cause blockage in large amounts, according to the case report. | Case report 1 |
| People who take medicines | Clay can bind medicines in the gut. Ask a pharmacist. | Human pk study 2 |
| Pets | A cat became ill after swallowing bentonite cat litter. Keep pets from licking clay products. | Animal case report 8 |
| Lung disease or asthma | Avoid breathing dry powder. No study of home use was found; the concern comes from workers. | Occupational 6 12 |
Overdose, product quality and regulators
Summary. Bentonite is a mineral, not a plant. The concerns are metals in some clays, blocked medicine absorption, constipation or blockage with large amounts by mouth, and dust.
Animal. A review reports bentonite and similar clays were not significantly toxic in short-term oral animal studies, but inhalation toxicity is readily shown in animals. A cat given bentonite litter had low potassium and anaemia.
Human doses studied. No safe amount to swallow is known. Trials used creams and masks, with no amounts stated in the abstracts.
High dose or long term signals. Large amounts by mouth may cause obstruction and electrolyte problems (case report authors). Reviews say the safety of eating clay is not fully established.
Overdose response. If someone has swallowed a clay product and feels unwell, call poison control (US 1-800-222-1222) or your local emergency number. Call 911 for collapse, seizure, trouble breathing or if the person cannot be woken.
Genotoxicity. Not read.
Clay is dug from the ground and can carry metals. A name such as bentonite does not tell you what is in a jar, and labels rarely say.
Lead and arsenic in clays for oral use. Dutch market, 63 clays: maximum lead 99.7 and arsenic 45.1 mg/kg. Estimated intake from 2 of 27 health clays exceeded the lead limit and from 11 of 27 the inorganic arsenic limit. The clays were not named by mineral in the abstract. 13
Lead in shop bentonite. No measured lead content for shop bentonite was found in the sources read.
Aluminium. No measured aluminium content or uptake for bentonite taken by mouth was found in the sources read. The cosmetic ingredient panel describes clay silicates as containing silicon, oxygen and one or more metals in their structure. 6
Clay can also hold metals. A review warns clay can adsorb heavy metals and make them available through eating or the skin. In water in the lab, bentonite took up lead, copper and nickel, which is not a human result. 7 5
| Body | Action | Date |
|---|---|---|
| US FDA (United States) | Cosmetic products and ingredients (except colour additives) do not need FDA premarket approval; FDA can act against non-compliant products on the market. source | 2025 |
| Cosmetic Ingredient Review (expert panel) (United States (industry-funded panel)) | Concluded bentonite and related clay silicates are safe as currently used in cosmetic formulations, and said any spray containing these solids should be formulated to minimise inhalation. source | 2003 |
| NCCIH (NIH) (United States) | Reports a 2015 review that found no compelling research that detox diets eliminate toxins from the body. source | 2025-03 |
| Poison Control (America's Poison Centers) (United States) | Online help or 1-800-222-1222; call 911 for collapse, seizure, trouble breathing or if the person cannot be woken. source | 2026 |
When to get medical help
- Collapse, a seizure, trouble breathing or being impossible to wake after swallowing or breathing in clay or clay dust: call emergency services (911 in the US) now.
- A child (or a pet) has swallowed a clay product, or you swallowed it and feel unwell: call poison control (US 1-800-222-1222) or your local emergency number.
- Weakness, vomiting, a very slow or uneven heartbeat, or lasting constipation or stomach pain after swallowing clay: get medical care now, because low potassium can be dangerous.
- Wheeze, cough or chest tightness after breathing in dry powder: stop and get medical advice.
- A skin problem that spreads, weeps, blisters or does not improve under a clay product: see a clinician.
Stop using the product and contact a clinician or emergency service. In the US, Poison Control is 1-800-222-1222.
General information only, not medical advice. Ask a clinician or pharmacist before use, especially with medicines, in pregnancy or with a health condition. See the Natural Remedy Safety guide.
Frequently asked questions
What is bentonite clay?
Is it safe to swallow?
We cannot say it is. A toddler had severely low potassium after bentonite by mouth and rectum, and the authors say large amounts by mouth could cause blockage. A review says the safety of eating clays is not fully established. If someone swallowed it and feels unwell, call poison control (US 1-800-222-1222).
Does bentonite contain lead or aluminium?
Can it cause constipation or a blockage?
A case report says large amounts by mouth have the potential to cause bowel obstruction. The child in it was already constipated, so one case cannot show how often it happens. Do not use bentonite for constipation.
Can clay stop my medicines from working?
Is bentonite a detox?
Does a bentonite mask work for skin?
Does it help diaper rash?
One double-blind trial of 100 infants found a bentonite cream improved diaper rash faster than a calendula cream. It had no placebo and did not describe the cream. Ask a paediatrician about a rash that is spreading or not improving.
Is it safe in pregnancy, while breastfeeding or for children?
Is breathing the dry powder a problem?
Is bentonite the same as montmorillonite?
Is clay regulated like a medicine?
Not as a cosmetic. The FDA says cosmetic products and ingredients, except colour additives, do not need premarket approval, though it can act against non-compliant products. Rules in other countries were not checked.
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Editorial transparency
- Written by
- AlternativeMed editorial team. Research compiled with AI assistance, then checked against PubMed records.
- Medical review
- None. This page has not been reviewed by a physician or pharmacist.
- First published
- 2026-10-30
- Last substantive update
- 2026-10-30
- How we research
- We searched PubMed, read the abstract of each cited paper, and read the FDA cosmetics, NCCIH detox and Poison Control pages. Certainty ratings are the compiler's own reading. Regulators outside the US were not checked. No study is cited that we could not verify.
- How we rate evidence
- See "How we rate evidence" in the Evidence tab.
- Independence
- No product is promoted on this page. No affiliate links are shown.
Sources 18
Each source was opened and checked. Where we read only the abstract, it says so. The small numbers in the text point here.
- Bennett A, Stryjewski G. Severe hypokalemia caused by oral and rectal administration of bentonite in a pediatric patient.. Pediatric Emergency Care. 2006. PMID 16871112. DOI 10.1097/01.pec.0000227873.05119.e6. (abstract)
- Boman G, Lundgren P, Stjernstrom G. Mechanism of the inhibitory effect of PAS granules on the absorption of rifampicin: adsorption of rifampicin by an excipient, bentonite.. European Journal of Clinical Pharmacology. 1975. PMID 1233228. DOI 10.1007/BF00562653. (abstract)
- Bonglaisin JN, Kunsoan NB, Bonny P, et al. Geophagia: Benefits and potential toxicity to human-A review.. Frontiers in Public Health. 2022. PMID 35958861. DOI 10.3389/fpubh.2022.893831. (abstract)
- Chebani R, Tahar Djebbar K, Daoud K. Sodium-activated Algerian bentonite with improved surface properties and topical barrier performance.. Journal of Pharmaceutical Sciences. 2026. PMID 41687876. DOI 10.1016/j.xphs.2026.104200. (abstract)
- Eleraky MI, Razek TMA, Hasani IW, et al. Adsorptive removal of lead, copper, and nickel using natural and activated Egyptian calcium bentonite clay.. Scientific Reports. 2025. PMID 40240407. DOI 10.1038/s41598-025-95184-7. (abstract)
- Elmore AR (Cosmetic Ingredient Review panel). Final report on the safety assessment of aluminum silicate, calcium silicate, magnesium aluminum silicate, magnesium silicate, magnesium trisilicate, sodium magnesium silicate, zirconium silicate, attapulgite, bentonite, Fuller's earth, hectorite, kaolin, lithium magnesium silicate, lithium magnesium sodium silicate, montmorillonite, pyrophyllite, and zeolite.. International Journal of Toxicology. 2003. PMID 12851164. (abstract)
- Gomes CSF. Healing and edible clays: a review of basic concepts, benefits and risks.. Environmental Geochemistry and Health. 2018. PMID 28150053. DOI 10.1007/s10653-016-9903-4. (abstract)
- Hornfeldt CS, Westfall ML. Suspected bentonite toxicosis in a cat from ingestion of clay cat litter.. Veterinary and Human Toxicology. 1996. PMID 8888544. (abstract)
- Kaneki M, Ohira C, Takahashi M, et al. Preventive effect of bentonite against pyoderma via direct binding capability of staphylococci.. PLoS One. 2026. PMID 41576001. DOI 10.1371/journal.pone.0341148. (abstract)
- Littman E, Winningham N, Carson TB, et al. Black Seed Oil, Bentonite Clay, and Probiotics: A Comprehensive Holistic Cure for Clostridium difficile Infection in a 2-Year-Old Female Child.. Case Reports in Infectious Diseases. 2022. PMID 35677311. DOI 10.1155/2022/2002488. (abstract)
- Mahmoudi M, Adib-Hajbaghery M, Mashaiekhi M. Comparing the effects of Bentonite & Calendula on the improvement of infantile diaper dermatitis: A randomized controlled trial.. Indian Journal of Medical Research. 2015. PMID 26831423. DOI 10.4103/0971-5916.174567. (abstract)
- O'Neill OJ, Costello J, Sullivan J, et al. Does exposure to bentonite dust during tunnel hyperbaric interventions increase health risks for compressed air workers? A prospective qualitative and quantitative safety assessment.. Undersea & Hyperbaric Medicine. 2019. PMID 31509901. (abstract)
- Reeuwijk NM, Klerx WN, Kooijman M, et al. Levels of lead, arsenic, mercury and cadmium in clays for oral use on the Dutch market and estimation of associated risks.. Food Additives & Contaminants Part A. 2013. PMID 23862762. DOI 10.1080/19440049.2013.811297. (abstract)
- Salimi S, Fakhri M, Saeedi M, et al. The Therapeutic Effects of a Bentonite-Based Facial Mask With Alcea sulphurea Extract on Acne Severity and Patient Experience: Add-On Randomized Controlled Clinical Trial.. Journal of Cosmetic Dermatology. 2025. PMID 41347526. DOI 10.1111/jocd.70586. (abstract)
- Zafar K, Lee A, Wang JY, et al. The potential cutaneous benefits of bentonites and montmorillonites.. Archives of Dermatological Research. 2024. PMID 39438324. DOI 10.1007/s00403-024-03456-5. (abstract)
- n/a. NCCIH (NIH): Detoxes and Cleanses: What You Need To Know (last updated March 2025). n/a. 2025. (full-text)
- n/a. US FDA: FDA Authority Over Cosmetics: How Cosmetics Are Not FDA-Approved, but Are FDA-Regulated. n/a. 2025. (full-text)
- n/a. Poison Control (America's Poison Centers): home page. n/a. 2026. (full-text)
