Herb & supplement monograph

Kaolin Drug Interactions, Uses, Effectiveness, Safety & More

Medically reviewed by ·Updated July 2026
What is this page for?

First and foremost: how Kaolin interacts with medications. The heart of this page is the interaction list — every drug Kaolin is known to interact with, and how serious each one is.

But these pages have grown well beyond that into a full monograph — what Kaolin is, what people use it for and how strong the evidence is, its safety and side effects, and answers to the questions we’re asked most — written and reviewed by the clinical staff at HelloPharmacist. It’s educational information from our licensed clinical databases, not medical advice, and we don’t sell or endorse products. Our editorial policy

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Kaolin Drug Interactions: The Bottom Line

From the HelloPharmacist Editorial Team · Updated July 2026

Based on the available evidence, the overall risk of a clinically significant Kaolin drug interaction is moderate for most people, mainly because this clay can bind to certain medicines in the stomach and reduce how much the body absorbs. None of the listed interactions are rated major, but all of them fall in the moderate range, and only a small number of medications are involved.

Interactions deserving the most attention

Digoxin deserves the most care because it is a heart medicine with a narrow safety margin, so even a modest change in absorption could matter, though the evidence here is conflicting. Trimethoprim has stronger human evidence that kaolin may reduce how much of the antibiotic gets absorbed, which could make it less effective. Clindamycin is also well studied, but kaolin only slows how quickly it is absorbed without changing the total amount, so the impact appears small.

What the rest of the list means

These interactions all work the same way: kaolin can physically bind medicines in the gut when taken close together, rather than changing how the body processes them. For some drugs, such as quinidine, the evidence is still preliminary, and in other cases the effect is on the speed of absorption rather than the amount, so not every combination will cause a meaningful problem.

Check your medications against Kaolin

Based on HelloPharmacist’s Kaolin interaction data and reviewed under our editorial standards.

Interaction report

Drugs that interact with Kaolin

7 medications have a known interaction with Kaolin, graded by severity. Select any drug for the full evidence-based detail.

2,830 drugs
ClindamycinCleocin, Cleocin T Gel, ClindaMax, Clindesse, Dalacin C› Clindamycin, Adapalene, Benzoyl PeroxideCabtreo› DigoxinDigitek, Lanoxicaps, Lanoxin› QuinidineCardioquin, Cin-Quin, Duraquin, Lin-Qin, Quinova, Quinaglute, Quinaglute Duratabs +2 more› Sulfadiazine, TrimethoprimCoptin› Sulfamethoxazole, TrimethoprimBactrim, Bactrim DS, Bactrim IV, Cotrim, Cotrim DS, Cotrimix +9 more› TrimethoprimProloprim, Trimpex› "phentolamineOraVerse, Rogitine, Ryzumvi› 6-mercaptopurinePurinethol› Ado-trastuzumab EmtansineKadcyla› AbacavirZiagen› Abacavir Sulfate, Dolutegravir, LamivudineTriumeq› Abacavir, LamivudineEpzicom› AbaloparatideTymlos› AbametapirXeglyze› AbarelixPlenaxis› AbciximabReoPro› AbemaciclibVerzenio› Abiraterone› Abiraterone AcetateYonsa, Zytiga› AbrocitinibCibinqo› AcalabrutinibCalquence› AcamprosateCampral› AcarboseGlucobay, Prandase, Precose› AcebutololRhotral, Sectral› AcenocoumarolSintrom› AcepromazineAtravet› AcetaminophenChildren's Tylenol, Children's Tylenol Meltaways, Tylenol, Tylenol Ex Strength› Acetaminophen, AspirinGemnisyn› Acetaminophen, Aspirin, CaffeineExcedrin, Excedrin Extra Strength, Excedrin Migraine›
Read The List Like a Pharmacist

What Severity, Likelihood & Evidence Mean

Severity — How Serious It Can Be

  • Major. Clinically significant; generally best avoided, or used only under direct professional supervision.
  • Moderate. May need monitoring, a dose adjustment, or separating the times you take each one.
  • Minor. Generally not clinically significant, but still worth noting and mentioning to your pharmacist.
  • No known interaction. Checked against our sources with nothing documented — not the same as proven safety.

Likelihood — How Well It’s Documented

  • Likely. Well-controlled human studies have demonstrated the likely existence of this interaction
  • Probable. Interaction has not been documented in well-controlled studies, however, the interaction has been demonstrated in some small human studies or in controlled animal studies in conjunction with multiple case reports.
  • Possible. Interaction has been documented in animal or in lab research, or the interaction has been documented in humans but is limited to case reports or conflicting clinical research exists
  • Unlikely. Interaction has been demonstrated in animal or in lab research but has been shown not to occur in humans.

Where This Data Comes From

  • Interaction records are evidence-graded and sourced from the Natural Medicines database (TRC Healthcare), the same reference used by pharmacists and hospitals.
  • Each drug listed above links to the full report for that exact Kaolin combination — clinical detail, likelihood, evidence level, and citations.
  • Content is reviewed by licensed HelloPharmacist pharmacists — see our data sources and editorial standards.
The big picture

The kinds of drugs Kaolin affects

Every type of medication (drug category) Kaolin is known to interact with. Open any category for the detail — or search your exact drug in the checker above.

All 4 drug categories Kaolin interacts with
Clindamycin (cleocin)Digoxin (lanoxin)QuinidineTrimethoprim (proloprim)
Clindamycin (Cleocin)

Kaolin appears to slow the rate of clindamycin absorption, but doesn't affect the extent of absorption.

Likelihood Probable Evidence B
Digoxin (Lanoxin)

Evidence is conflicting about the effect of kaolin on digoxin pharmacokinetics. To avoid a potential interaction, separate digoxin and kaolin doses by at least 3 hours.

Likelihood Possible Evidence B
Quinidine

Preliminary evidence suggests that kaolin might decrease quinidine absorption. To avoid a potential interaction, separate quinidine and kaolin doses by at least 3 hours.

Likelihood Possible Evidence D
Trimethoprim (Proloprim)

Kaolin may reduce the absorption of trimethoprim. To avoid a potential interaction, separate trimethoprim and kaolin doses by at least 3 hours.

Likelihood Probable Evidence B
Monograph

Kaolin: Uses, Safety & Side Effects

Medically reviewed by · Reviewed July 2026 ·
The bottom line

Kaolin is a soft, white clay mineral that has long been used in antidiarrheal products and skincare because it absorbs water and binds substances in the gut. Older diarrhea products often combined it with pectin, but modern guidelines favor rehydration and other treatments, and high-quality evidence for kaolin alone is limited. It is generally considered low-risk for short-term use, but check with your pharmacist or doctor before use, especially during pregnancy or breastfeeding.

Kaolin
Part used
Mineral clay (hydrated aluminum silicate)
Common forms
Oral suspensions, tablets, powders, topical pastes and masks
People commonly use it for
  • Diarrhea
  • Upset stomach and nausea
  • Skincare and facial masks
  • Soothing minor skin irritation
  • Excessive salivation (traditional)

Popular and traditional uses — not proof it works. See “Uses & effectiveness” below for the evidence.

Safety at a glance
OverallUse caution

Generally considered low-risk for short-term use, but long-term or excessive use is not well studied.

PregnancyLikely Safe

When used orally in food amounts. Kaolin has Generally Recognized as Safe (GRAS) status in the US.

Read the full pregnancy detail
BreastfeedingLikely Safe

When used orally in food amounts. Kaolin has Generally Recognized as Safe (GRAS) status in the US.

Read the full breastfeeding detail

Pregnancy & breastfeeding ratings are from Natural Medicines (Therapeutic Research Center). Safety guidance is general; always confirm with your pharmacist or doctor for your situation.

Jump to a section

Overview

Kaolin is a naturally occurring soft, white clay mineral made mostly of hydrated aluminum silicate. It is also called china clay or white bole. It is mined from the earth in many parts of the world and then purified before being used.

Kaolin has many uses outside of health, including making paper, ceramics, and paint. In medicine and personal care, it has been used as an ingredient in some antidiarrheal products and in skincare items such as facial masks and powders because it can absorb moisture and oils.

Traditionally, people have also used clays like kaolin to ease stomach upset, nausea, and diarrhea. It is important to know that traditional or popular use does not mean a product is proven to work.

How it works

Kaolin is thought to work mainly as an adsorbent. This means its fine particles can bind to water, toxins, bacteria, and other substances in the gut. By soaking up extra fluid, it may help make loose stools firmer.

On the skin, kaolin's absorbent nature lets it pull up oil and moisture, which is why it is used in masks and powders.

These actions are based largely on the physical properties of the clay and on laboratory observations. The exact effect inside the human body, and how strong it is, is not fully proven.

Effectiveness

Does Kaolin work?

Here’s what the research actually shows for each use — graded by Natural Medicines and reviewed by .

Evidence overview · 2 uses evaluated
2 Possibly effective
How to read these evidence grades

Natural Medicines’ 7-point scale. We show each rating’s label word-for-word.

1EffectiveStrong, consistent evidence it works.
2Likely EffectiveGood evidence, though not yet conclusive.
3Possibly EffectiveSome evidence suggests a benefit.
4Possibly IneffectiveSome evidence it may not help.
5Likely IneffectiveFairly strong evidence it doesn’t help.
6IneffectiveStrong evidence it doesn’t work.
7Insufficient Reliable Evidence to RateToo little research to say either way.
Possibly Effective Bleeding
Rating & evidence shown verbatim from Natural Medicines

Kaolin-impregnated gauze has shown some benefit for reducing bleeding in various situations, including post-procedural bleeding, postoperative bleeding, and bleeding associated with wound debridement.

Possibly Effective Oral mucositis
Rating & evidence shown verbatim from Natural Medicines

Using 15 mL of a mouthwash containing a 1:1 mixture of kaolin-pectin and diphenhydramine syrup held in the mouth for 3 minutes after meals and at bedtime for 3 weeks helps to reduce pain associated with radiation-induced mucositis. A similar mouthwash containing a 1:1:1 mixture of kaolin pectin, diphenhydramine, and saline also helps to reduce pain associated with radiation- or chemotherapy-induced mucositis when used for the duration of therapy in amounts and frequency chosen by the patient. The mouthwash is either gargled and expectorated or applied to mouth lesions with a sponge.

Sources Ref 186 Ref 187

Source & disclaimer. Effectiveness ratings and evidence summaries are provided by Natural Medicines (Therapeutic Research Center) and shown as licensed. Where Natural Medicines hasn’t rated a use, HelloPharmacist’s pharmacists may add their own reviewed rating and evidence (each such entry is labeled). This is educational information, not medical advice — talk with your pharmacist or doctor before starting, stopping, or changing a supplement.

Safety & precautions

For short-term use, kaolin is generally considered low-risk for most adults. However, it should be used carefully and not for long periods unless a healthcare provider advises it.

Because kaolin can absorb fluids and substances in the gut, it may affect how well your body takes in nutrients or medicines if used heavily or often. Diarrhea that is severe, bloody, lasts more than a couple of days, or comes with high fever or signs of dehydration needs medical attention rather than self-treatment with clay products.

Eating clay outside of approved products (a practice sometimes called pica or geophagy) can be harmful and may lead to constipation, blockages, or mineral problems. Pregnancy: some pregnant people crave and eat clay, which is not safe; avoid kaolin during pregnancy unless your provider recommends it. Breastfeeding: there is little information on safety, so check with your doctor or pharmacist before using it. Always talk to a pharmacist or doctor before giving kaolin products to children.

Side effects

When used as directed for a short time, kaolin is usually well tolerated. The most common side effect is constipation, since it firms up stool.

Heavy or long-term use may cause more serious gut problems, such as blockage, or may affect how your body absorbs nutrients and minerals. Eating non-pharmaceutical clay can be especially risky.

If you notice severe stomach pain, swelling, inability to pass stool, or an allergic reaction such as rash or trouble breathing, stop using it and seek medical care.

Kaolin: Reported Adverse Effects

Documented safety reports on Kaolin from the evidence-graded Natural Medicines (TRC Healthcare) database, shown word-for-word from the licensed record.

Orally, kaolin can cause constipation, particularly in children and the elderly. It can also cause intestinal obstruction. After inhalation, kaolin may cause occupational kalinosis (pulmonary disease).

  1. McEvoy GK, ed. AHFS Drug Information. Bethesda, MD: American Society of Health-System Pharmacists, 1998.
  2. Dokoupil M, Marecová K, Handlos P, Brezina P. Death of a female prostitute due to intestinal obstruction by an unknown substance. J Forensic Sci 2019;64(1):289-91. doi: 10.1111/1556-4029.13824.
  3. Levin JL, Frank AL, Williams MG, et al. Kaolinosis in a cotton mill worker. Am J Ind Med 1996;29:215-21.
  4. Chaudhary BA, Kanes GJ, Pool WH. Pleural thickening in mild kaolinosis. South Med J 1997;90:1106-9.
  5. Altekruse EB, Chaudhary BA, Pearson MG, Morgan WK. Kaolin dust concentrations and pneumoconiosis at a kaolin mine. Thorax 1984;39:436-41.
Reports by condition
Anemia Gastrointestinal

Orally, kaolin can cause constipation, particularly in children and the elderly. When consumed in large quantities, kaolin can cause intestinal obstruction, which can be fatal in severe cases. It can also interfere with absorption of nutrients. Several case reports describe patients presenting with pelvic and abdominal pain, headache, lightheadedness with presyncope, intermittent constipation, and severe iron deficiency anemia after taking kaolin daily for 2-3 years.

  1. McEvoy GK, ed. AHFS Drug Information. Bethesda, MD: American Society of Health-System Pharmacists, 1998.
  2. Dokoupil M, Marecová K, Handlos P, Brezina P. Death of a female prostitute due to intestinal obstruction by an unknown substance. J Forensic Sci 2019;64(1):289-91. doi: 10.1111/1556-4029.13824.
  3. Pain S, Fauconneau B, Bouquet E, Vasse-Terrier L, Pérault-Pochat MC. Severe craving associated with kaolin consumption. Eat Weight Disord 2019;24(2):379-81. doi: 10.1007/s40519-018-0583-1.
  4. Attarha BO, Mikulic S, Harris C, Scolapio JS. Kaolin Clay Anemia. Cureus 2021;13(3):e13796.
DISCLAIMER: This tool is intended for informational purposes only, and should not be interpreted as specific medical advice. Patients should consult with a qualified healthcare provider before making decisions about therapies and/or health conditions.

Adverse-effects data: Natural Medicines, Therapeutic Research Center

Dosing

There is no single official supplement dose for kaolin, and products vary widely in strength and formulation. The best approach is to follow the directions on the product label exactly.

Do not exceed the recommended amount or use it for longer than directed without medical advice. If you are unsure how much to take, how often, or whether it is right for your situation, ask a pharmacist or doctor before using it.

Pregnancy & Breastfeeding

Kaolin & Pregnancy

Likely Safe

When used orally in food amounts. Kaolin has Generally Recognized as Safe (GRAS) status in the US.

  1. Electronic Code of Federal Regulations. Title 21. Part 182 -- Substances Generally Recognized As Safe. Available at: https://www.accessdata.fda.gov/scripts/cdrh/cfdocs/cfcfr/CFRSearch.cfm?CFRPart=182
Possibly Safe

When used orally as kaolin-pectin in appropriate amounts.

  1. Black RA, Hill DA. Over-the-counter medications in pregnancy. Am Fam Physician 2003;67:2517-24.

Kaolin & Breastfeeding

Likely Safe

When used orally in food amounts. Kaolin has Generally Recognized as Safe (GRAS) status in the US.

  1. Electronic Code of Federal Regulations. Title 21. Part 182 -- Substances Generally Recognized As Safe. Available at: https://www.accessdata.fda.gov/scripts/cdrh/cfdocs/cfcfr/CFRSearch.cfm?CFRPart=182
Possibly Safe

When used orally as kaolin-pectin in appropriate amounts.

  1. Black RA, Hill DA. Over-the-counter medications in pregnancy. Am Fam Physician 2003;67:2517-24.
DISCLAIMER: This tool is intended for informational purposes only, and should not be interpreted as specific medical advice. Patients should consult with a qualified healthcare provider before making decisions about therapies and/or health conditions.

© 2026 Therapeutic Research Center

Pregnancy & lactation ratings: Natural Medicines, Therapeutic Research Center

References & further reading

The 18 references that drive our Kaolin monograph and interaction data, from the evidence-graded Natural Medicines (TRC Healthcare) database. Citations with a link open the study on PubMed or the publisher’s site.

  1. McEvoy GK, ed. AHFS Drug Information. Bethesda, MD: American Society of Health-System Pharmacists, 1998.
  2. Barker G, Loftus L, Cuddy P, Barker B. The effects of sucralfate suspension and diphenhydramine syrup plus kaolin-pectin on radiotherapy-induced mucositis. Oral Surg Oral Med Oral Pathol 1991;71:288-93.
  3. Carnel SB, Blakeslee DB, Oswald SG, Barnes M. Treatment of radiation- and chemotherapy-induced stomatitis. Otolaryngol Head Neck Surg 1990;102:326-30.
  4. Levin JL, Frank AL, Williams MG, et al. Kaolinosis in a cotton mill worker. Am J Ind Med 1996;29:215-21.
  5. Chaudhary BA, Kanes GJ, Pool WH. Pleural thickening in mild kaolinosis. South Med J 1997;90:1106-9.
  6. Altekruse EB, Chaudhary BA, Pearson MG, Morgan WK. Kaolin dust concentrations and pneumoconiosis at a kaolin mine. Thorax 1984;39:436-41.
  7. Rodin SM, Johnson BF. Pharmacokinetic interactions with digoxin. Clin Pharmacokinet 1988;15:227-44.
  8. Babhair SA, Tariq M. Effect of magnesium trisilicate and kaolin-pectin on the bioavailability of trimethoprim. Res Commun Chem Pathol Pharmacol 1983;40:165-8.
  9. Bucci AJ, Myre SA, Tan HS, Shenouda LS. In vitro interaction of quinidine with kaolin and pectin. J Pharm Sci 1981;70:999-1002.
  10. Allen MD, Greenblatt DJ, Harmatz JS, Smith TW. Effect of magnesium-aluminum hydroxide and kaolin-pectin on absorption of digoxin from tablets and capsules. J Clin Pharmacol 1981;21:26-30. PubMed
  11. Albert KS, Ayres JW, DiSanto AR, et al. Influence of kaolin-pectin suspension on digoxin bioavailability. J Pharm Sc 1978;67:1582-6.
  12. Albert KS, et al. Pharmacokinetic evaluation of a drug interaction between kaolin-pectin and clindamycin. J Pharm Sci 1978 67:1579-82.
  13. Electronic Code of Federal Regulations. Title 21. Part 182 -- Substances Generally Recognized As Safe. Available at: https://www.accessdata.fda.gov/scripts/cdrh/cfdocs/cfcfr/CFRSearch.cfm?CFRPart=182
  14. Black RA, Hill DA. Over-the-counter medications in pregnancy. Am Fam Physician 2003;67:2517-24.
  15. Electronic Code of Federal Regulations. Title 21. Part 335 - Antidiarrheal drug products for over-the-counter human use. Available at: https://www.accessdata.fda.gov/scripts/cdrh/cfdocs/cfcfr/CFRSearch.cfm?fr=335.50
Keep reading

This information is for education only and is not a substitute for professional medical advice. Always check with your pharmacist or doctor before starting, stopping, or combining supplements and medications.

Parts of this content are provided by the Therapeutic Research Center, LLC.

DISCLAIMER: Currently this does not check for drug-drug interactions. This is not an all-inclusive comprehensive list of potential interactions and is for informational purposes only. Not all interactions are known or well-reported in the scientific literature, and new interactions are continually being reported. Input is needed from a qualified healthcare provider including a pharmacist before starting any therapy. Application of clinical judgment is necessary.

© 2021 Therapeutic Research Center, LLC

Brand directory

Brands that make products with Kaolin

6 brands in our database make a supplement containing Kaolin.

Product directory

Supplement products with Kaolin

8 products in our database contain Kaolin. Open any to see its full ingredient list and every drug interaction we check.

Pharmacist Counseling Corner

Kaolin: Common Questions

What is Kaolin used for, and does it work?
People use Kaolin for many reasons, but the evidence varies by use. According to the Natural Medicines database, there is at least some clinical evidence supporting Kaolin for Bleeding and Oral mucositis. For most other uses it has been studied for, the evidence is currently insufficient to rate. See the graded list on this page, and always confirm with your pharmacist or doctor.
Does Kaolin interact with prescription medications?
Yes. We list 7 medications with a known interaction with Kaolin. Use the checker above to see how Kaolin interacts with a specific drug.
How are Kaolin interactions rated?
Each interaction is graded major, moderate, or minor based on how clinically significant it is and the strength of the evidence behind it. Major interactions are the most serious and are best avoided, or used only under close professional supervision.
Is it safe to take Kaolin with my medications?
It depends on the specific medication. Some combinations are fine, while others call for monitoring, timing changes, or should be avoided. Check your exact drug above and confirm with your pharmacist or doctor before starting, stopping, or changing anything.
Where does this Kaolin interaction information come from?
Our interaction data is built on the Natural Medicines database — an evidence-graded reference for vitamins, herbs, and supplements — and is reviewed by licensed HelloPharmacist pharmacists, who may add clinical context.
What is Kaolin used for?
Kaolin is a clay mineral most often used as an absorbent ingredient in some antidiarrheal products and in skincare items like masks. It has also been used traditionally for nausea and upset stomach, though strong evidence is limited.
Is Kaolin safe to take?
For most adults, short-term use as directed is generally considered low-risk. Long-term or excessive use is not well studied and can cause constipation or other gut problems, so check with your pharmacist or doctor.
Can I use Kaolin if I am pregnant or breastfeeding?
It is best to avoid Kaolin during pregnancy and breastfeeding unless your healthcare provider tells you it is okay, since safety is not well established and eating clay can be harmful.
Does Kaolin stop diarrhea?
Kaolin can absorb water and may make stools firmer, but high-quality evidence that it shortens diarrhea is limited. Rehydration and fluids are the most important step, and persistent or severe diarrhea needs medical care.

Written and reviewed by the HelloPharmacist editorial staff. Our editorial policy

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Products that contain Kaolin

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See all 8 products with Kaolin →
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