Drug & supplement interaction

Clay + Diltiazem

Diltiazem brand names: Cardizem, Cardizem SR, Diltiaz SR, Cardizem CD, Tiazac, and others.

No Known Interaction
Medically reviewed by · Updated July 2026 · Pair last verified Sep 20, 2026
The bottom line No known interaction

We found no known interaction between Clay and Diltiazem in our sources. Absence of a documented interaction is not the same as proven safety, and does not guarantee one does not exist. Do not start, stop, or change a medication or supplement based on this page; confirm with your pharmacist or doctor first. Additionally, although there is no interaction, the two are separately associated with some of the same side effects, which would make a new symptom harder to attribute to one or the other.

Know someone taking this? Share
Facebook Post Reddit Email
On this page
Interaction report

Clay and Diltiazem

We checked these two against our interaction database. Here is what we found.

No Known Interaction Found

We did not find a documented interaction between Diltiazem and Clay in our sources. This does not guarantee that the combination is completely free of risk — there is often limited research on supplements and herbal products, especially around drug interactions.

If you decide to take both, the practical routine is simple: add one new thing at a time and note the date you started it. If the combination is going to disagree with you, it usually shows in the first days to a couple of weeks — and a start date turns “I’ve been feeling off” into something a pharmacist can actually work with. Do not stop a prescribed medicine on your own.

Always talk with your pharmacist or doctor before making changes to your medications or supplements, particularly if you take several medications or have an ongoing health condition.

Clay safety at a glance

Clay overall Use caution Topical use is generally low-risk, but oral clay can be contaminated with heavy metals.
Pregnancy Possibly Unsafe When used orally, long-term. Clay ingestion during pregnancy appears to be associated with an increased incidence of pre-eclampsia, hypertension, and/or edema.... Read the full pregnancy detail
Breastfeeding Avoid Not enough safety data; avoid taking clay by mouth while breastfeeding.

Pregnancy & breastfeeding ratings are from Natural Medicines (Therapeutic Research Center) — the full detail is in the Special populations card below. Safety guidance is general; always confirm with your pharmacist or doctor for your situation.

Still wondering about combining Diltiazem and Clay? Ask Dr. Brian Staiger, PharmD, BCPS directly ›
How we checked

Why No Interaction Is Listed for Diltiazem

Interactions in our licensed database are recorded against drug classes, not just single drug names. Diltiazem is filed under 9 classifications — including calcium channel blockers, cytochrome p450 1a2 (cyp1a2) inhibitors, cytochrome p450 3a4 (cyp3a4) inhibitors. Clay has documented interactions with 2 drug classes — the most serious being cimetidine (tagamet) (moderate) and quinine (moderate) — and none of Diltiazem’s classifications are among them.

Classification data comes from our licensed Natural Medicines dataset. A medication can belong to classes beyond those recorded there, so this describes how the check was run — it is not a safety guarantee.

Keep it in perspective

Clay Does Interact With Other Medications

Clay has 3 moderate known drug interactions in our database — Diltiazem isn’t one of them. If you take anything else, check it against the full list below.

Moderate 3 No known interaction 2,827 (incl. Diltiazem)
Taking anything else?

Check Another of Your Medications Against Clay

Covers the 2,830 medications we’ve checked against Clay. Pick one to open its full report.

What to actually watch for

No Interaction Found — But Data Suggests Clay and Diltiazem May Share Several of the Same Side Effects

This is not an interaction. Neither one changes how your body handles the other, and nothing here says they react together. What our sources do show is that each has separately been linked to the effects below — so taking both can make those effects more likely to turn up, and harder to pin on one or the other if they do.

  • Bloating or gas / Reduced appetite / Constipation / Diarrhea / Vomiting reported in 6.1% of FDA reports for Diltiazem Additional detail

    Clay

    “Orally, clay seems to be well tolerated when used short-term. Adverse effects are generally mild and include constipation, vomiting, and diarrhea. Long-term ingestion of clay has been associated with more serious adverse effects.”

    Clay · Natural Medicines adverse-effect record, reported in anemia.

    6 sources cited
    1. 26617. Wang JS, Luo H, Billam M, et al. Short-term safety evaluation of processed calcium montmorillonite clay (NovaSil) in humans. Food Addit Contam 2005;22(3):270-9. PubMed
    2. 98648. Kee BK, Morris JS, Slack RS, et al. A phase II, randomized, double blind trial of calcium aluminosilicate clay versus placebo for the prevention of diarrhea in patients with metastatic colorectal cancer treated with irinotecan. Support Care Cancer. 2015;2 PubMed
    3. 98652. Lin JX, Fan ZY, Lin Q, et al. A comparison of dioctahedral smectite and iodine glycerin cream with topical mouth rinse in treatment of chemotherapy induced oral mucositis: a pilot study. Eur J Oncol Nurs. 2015;19(2):136-41. PubMed
    4. 98646. Pérez-Gaxiola G, Cuello-García CA, Florez ID, Pérez-Pico VM. Smectite for acute infectious diarrhoea in children. Cochrane Database Syst Rev. 2018;4:CD011526. PubMed
    5. 98649. Mitchell NJ, Kumi J, Aleser M, et al. Short-term safety and efficacy of calcium montmorillonite clay (UPSN) in children. Am J Trop Med Hyg. 2014;91(4):777-85. PubMed
    6. 101813. Lai BY, Liang N, Cao HJ, et al. Pediatric Tui Na for acute diarrhea in children under 5 years old: A systematic review and meta-analysis of randomized clinical trials. Complement Ther Med. 2018;41:10-22. PubMed

    “Orally, the most commonly reported adverse effects in clinical trials is constipation. Vomiting and diarrhea have been reported rarely. Long-term ingestion of clay may induce constipation, diarrhea, heartburn, flatulence, loss of appetite, and vomiting after meals. Clay ingestion has also been associated with intestinal obstruction and necrotizing enteritis, leading to bowel perforation.”

    Clay · Natural Medicines adverse-effect record, reported in constipation.

    6 sources cited
    1. 98646. Pérez-Gaxiola G, Cuello-García CA, Florez ID, Pérez-Pico VM. Smectite for acute infectious diarrhoea in children. Cochrane Database Syst Rev. 2018;4:CD011526. PubMed
    2. 101813. Lai BY, Liang N, Cao HJ, et al. Pediatric Tui Na for acute diarrhea in children under 5 years old: A systematic review and meta-analysis of randomized clinical trials. Complement Ther Med. 2018;41:10-22. PubMed
    3. 98649. Mitchell NJ, Kumi J, Aleser M, et al. Short-term safety and efficacy of calcium montmorillonite clay (UPSN) in children. Am J Trop Med Hyg. 2014;91(4):777-85. PubMed
    4. 26611. Carpenter WM. Observations on Cachexia Africana, on habits and effects of dirt eating in negro race. New Orleans Med Surg J 1844;1:146-68.
    5. 26616. Andrews PL, Horn CC. Signals for nausea and emesis: Implications for models of upper gastrointestinal diseases. Auton Neurosci 2006;125(1-2):100-15. PubMed
    6. 26617. Wang JS, Luo H, Billam M, et al. Short-term safety evaluation of processed calcium montmorillonite clay (NovaSil) in humans. Food Addit Contam 2005;22(3):270-9. PubMed

    Diltiazem

    Listed in the ADVERSE REACTIONS section of the FDA label for Diltiazem, and in voluntary FDA adverse-event reports. Read the label on DailyMed ›

  • A fast or pounding heartbeat Additional detail

    Clay

    “Orally, habitual clay intake has been associated with heart lesions, cardiomyopathy, and painful heart palpitations.”

    Clay · Natural Medicines adverse-effect record, reported in cardiomyopathy.

    1 source cited
    1. 26611. Carpenter WM. Observations on Cachexia Africana, on habits and effects of dirt eating in negro race. New Orleans Med Surg J 1844;1:146-68.

    Diltiazem

    Listed in the ADVERSE REACTIONS section of the FDA label for Diltiazem. Read the label on DailyMed ›

  • Swelling Additional detail

    Clay

    “Cases of hypokalemia-induced muscle weakness and muscle swelling have been reported after ingestion of large quantities of clay.”

    Clay · Natural Medicines adverse-effect record, reported in hypokalemia.

    3 sources cited
    1. 26606. Severance HW Jr, Holt T, Patrone NA, Chapman L. Profound muscle weakness and hypokalemia due to clay ingestion. South Med J 1988;81(2):272-4. PubMed
    2. 26615. Ukaonu C, Hill DA, Christensen F. Hypokalemic myopathy in pregnancy caused by clay ingestion. Obstet Gynecol 2003;102(5 Pt 2):1169-71. DOI
    3. 26627. Trivedi TH, Daga GL, Yeolekar ME. Geophagia leading to hypokalemic quadriparesis in a postpartum patient. J Assoc Physicians India 2005;53:205-7.

    Diltiazem

    Listed in the ADVERSE REACTIONS section of the FDA label for Diltiazem. Read the label on DailyMed ›

Reported for Clay but not commonly for Diltiazem: a bowel blockage, muscle weakness, severe muscle breakdown and low potassium.

Effects for Diltiazem come from the ADVERSE REACTIONS section of its FDA label; effects for Clay come from the Natural Medicines adverse-effect record, quoted above. Where a percentage is shown, it is the share of 34,400 voluntary FDA FAERS reports for Diltiazem that mention that effect — a reporting proportion, not an incidence rate and not evidence the drug caused it. Wording is matched across sources by our own clinical vocabulary, so treat this as a prompt to pay attention, not a diagnosis.

Special populations

Clay in Pregnancy & Breastfeeding

Pregnancy Possibly Unsafe

When used orally, long-term. Clay ingestion during pregnancy appears to be associated with an increased incidence of pre-eclampsia, hypertension, and/or edema. There is insufficient reliable information available about the safety of ingesting clay short-term during pregnancy.

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

From our Q&A

Questions About Clay or Diltiazem

These are real questions from readers, answered by the pharmacists at HelloPharmacist — written by a person, not generated from a database. Each one covers Clay or Diltiazem, not necessarily both, but if one is close to what you were about to ask it will usually go further than a database entry can:

Not quite your question? Ask our pharmacists directly — it is free, there is no account required, and answers usually come back within 24 hours.

Everything else you take

See Every Supplement That Interacts With Diltiazem

This page covers Clay only. If you take other supplements — a multivitamin, a sleep aid, something for joints — the Diltiazem page lists 260 supplements it has a documented interaction with, worst first, each one explained.

The most serious there right now: Activated Charcoal (major), American Hellebore (major), American Mistletoe (major), Coleus (major) and Grapefruit (major).

By severity: 7 major · 214 moderate · 39 minor.

From our pharmacist’s overview on the Diltiazem page

“Someone on diltiazem (Cardizem, Tiazac) is usually managing blood pressure, angina, or a fast heart rhythm, so this list deserves genuine care. Seven of the 260 ingredients on file carry a major rating, and two of those are things people actually buy: grapefruit, which blocks the enzyme that clears diltiazem and can push its blood leve…”

Reviewed by 2 · Jul 18, 2026

Open the Diltiazem interaction page

One more smart check

Taking Clay as Part of a Dietary Supplement Product? Check It for Interactions

We hold 17 real supplement products containing Clay, each one broken down to its full ingredient list — and combination products often carry several ingredients besides Clay. Even though Clay itself has no known interaction with Diltiazem, another ingredient on your label might. Find your product and we’ll check every ingredient on its label:

How much people look this up

Where Clay and Diltiazem Sit Against Everything Else

Out of every supplement and medication people look up on HelloPharmacist, here is where these two land this week — and which way each has been moving.

Supplement Clay
Steady interest

#910 of 1,452 supplements looked up here in the last 7 days

29 days ago today
Medication Diltiazem
Top 25%

#303 of 2,830 medications looked up here in the last 7 days

29 days ago today

Position among everything looked up on this site, not a measure of how commonly either one is used or how important it is. A supplement can climb this list because of a news story. It counts every request to the page, automated ones included, and nothing here identifies anyone.

Where does our data come from?
  • Source: the Natural Medicines (TRC Healthcare) clinical database — the evidence-graded professional reference for herb & supplement interactions.
  • Citation library: 103,510 references behind our interaction content, 65,311 of them resolved to verified PubMed/DOI sources. See every Clay reference on this page ↓
  • Freshness: we automatically re-check this combination every week — this pair was last verified September 20, 2026. The Clay and Diltiazem records this page draws on were last updated July 11, 2026.
  • What “no known interaction” means: no documented interaction in the sources above — not a guarantee of safety. Supplements are studied far less than prescription drugs, so we say exactly what the evidence supports, and nothing more.
Data structure & sourcing designed and verified by .
Supplement

About Clay

What is Clay?

  • Detox and digestive complaints
  • Skin care (masks, acne, irritation)
  • Diarrhea and upset stomach
  • Drawing out toxins or impurities
  • Wound and rash poultices

Clay is a fine, mineral-rich earth (such as bentonite or kaolin) used on the skin and sometimes taken by mouth for digestive and 'detox' purposes. Topical use for masks and minor skin issues is popular and generally low-risk, but swallowing clay carries real safety concerns, including possible contamination with lead and other heavy metals. Talk to a pharmacist or doctor before taking clay internally.

Mineral-rich clay (bentonite, kaolin, French green clay, and similar) · Powder, capsules, masks, poultices, suspensions/drinks

An interaction check asks whether these two react with each other — it does not ask whether Clay is a good idea for someone in your situation. Here is what our Clay record says about it on its own.

Clay: dosing

There is no well-established, standardized dose for clay, and no recommended safe amount for eating it. Because of contamination and absorption concerns, taking clay internally is generally not recommended without medical guidance.If you use a topical product, follow the label directions for how long to leave a mask on and how often to use it. Choose products that are independently tested for heavy metals.

From our Clay monograph — the full record covers uses, side effects and every documented interaction.

Read the full Clay monograph & all interactions
Medication

About Diltiazem

What Is Diltiazem Used For?

Brand names: Cardizem, Cardizem SR, Diltiaz SR, Cardizem CD, Tiazac, Diltiaz XT, Diltiaz CD, Dilacor, Diltiaz, Cardizem LA, Dilacor XR, Cartia XT, Tiamate, Adizem-SR, Adizem-XL, Angitil SR, Angitil XL, Calcicard CR, Dilcardia SR, Dilzem SR, Dilzem XL, Slozem, Tildiem LA, Tildiem Retard, Viazem XL, Zemtard 120XL, Zemtard 180XL, Zemtard 240XL, Zemtard 300XL

Oral extended-release forms of diltiazem — including Matzim LA, Cardizem LA, Cartia, Cartia XT, Tiadylt ER, and various generic capsules and tablets — are used to treat high blood pressure (hypertension) and chronic stable angina (chest pain brought on by activity). Some capsule formulations, including Cartia, Cartia XT, and certain generics, are also approved for angina due to coronary artery spasm (sudden chest pain caused by a sudden tightening of a coronary artery).

Injectable forms of diltiazem are used in hospital settings to temporarily slow a dangerously fast heart rate in atrial fibrillation or atrial flutter (rapid, irregular heart rhythms), and to restore a normal heart rhythm in paroxysmal supraventricular tachycardia (PSVT) — sudden episodes of a very fast but regular heartbeat originating above the heart's lower chambers.

Most-Reported Side Effects for Diltiazem

From FAERS, the FDA’s public side-effect reporting system (34,400 reports, all brands). Reports are voluntary and are not proof the drug caused the effect.

Dyspnea 3,309 reports
Fatigue 2,733 reports
Nausea 2,454 reports
Dizziness 2,174 reports
Diarrhea 2,113 reports
See full Diltiazem drug information
Keep checking

Other Drugs & Clay

Browse every other medication we’ve checked against Clay — both the ones with a known interaction and the ones without. Select any drug for the full detail.

0Major
3Moderate
0Minor
2,826No known interaction
3 Moderate 2,826 No interaction
Moderate

3 interactions

No interaction 2,826 drugs checked — show the list

We also checked Clay against these medications and found no known interaction in our sources. Open any page to confirm.

Showing the 60 most looked-up of 2,826 medications checked with no known interaction — see the full Clay list.

See the full Clay interactions page
See every supplement checked against Diltiazem, ranked by severity
Evidence & sources

Clay References

The 31 references that drive our Clay 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. Gonzalez JJ, Owens W, Ungaro PC, et al. Clay ingestion: a rare cause of hypokalemia. Ann Intern Med 1982;97(1):65-6. PubMed
  2. Mengel CE, Carter WA, Horton ES. Geophagia with iron deficiency and hypokalemia. Cachexia Africana. Arch Intern Med 1964;114:470-4. PubMed
  3. Severance HW Jr, Holt T, Patrone NA, Chapman L. Profound muscle weakness and hypokalemia due to clay ingestion. South Med J 1988;81(2):272-4. PubMed
  4. Minnich V, Okcuoglu A, Tarcon Y, et al. Pica in Turkey. II. Effect of clay upon iron absorption. Am J Clin Nutr 1968;21(1):78-86.
  5. O'Rourke DE, Quinn JG, Nicholson JO, Gibson HH. Geophagia during pregnancy. Obstet Gynecol 1967;29(4):581-4.
  6. Edwards CE, McDonald S, Mitchell JK, et al. Effect of clay and cornstarch intake on women and their infants. J Amer Diet Assoc 1964;44:109-15. DOI
  7. Carpenter WM. Observations on Cachexia Africana, on habits and effects of dirt eating in negro race. New Orleans Med Surg J 1844;1:146-68.
  8. Ducrotte P, Dapoigny M, Bonaz B, Siproudhis L. Symptomatic efficacy of beidellitic montmorillonite in irritable bowel syndrome: a randomized, controlled trial. Aliment Pharmacol Ther 2005;21(4):435-44. PubMed
  9. Chang FY, Lu CL, Chen CY, Luo JC. Efficacy of dioctahedral smectite in treating patients of diarrhea-predominant irritable bowel syndrome. J Gastroenterol Hepatol 2007;22(12):2266-72. PubMed
  10. Blum M, Orton C, Rose L. The effect of starch ingestion on excessive iron association, abstracted. Ann Intern Med 1968;68:1165.
  11. Ukaonu C, Hill DA, Christensen F. Hypokalemic myopathy in pregnancy caused by clay ingestion. Obstet Gynecol 2003;102(5 Pt 2):1169-71. DOI
  12. Andrews PL, Horn CC. Signals for nausea and emesis: Implications for models of upper gastrointestinal diseases. Auton Neurosci 2006;125(1-2):100-15. PubMed
  13. Wang JS, Luo H, Billam M, et al. Short-term safety evaluation of processed calcium montmorillonite clay (NovaSil) in humans. Food Addit Contam 2005;22(3):270-9. PubMed
  14. Bateson EM, Lebroy T. Clay eating by Aboriginals of the Northern Territory. Med J Aust 1978;1 Suppl 1:1-3. PubMed
  15. Delaitre B, Lemaigre G, Acar JF, et al. [Necrotizing enteritis and geophagia]. Nouv Presse Med 1976;5(28):1743-6.

Medication overviews come from MedlinePlus (NIH); supplement label data from the NIH Dietary Supplement Label Database. Content is written and reviewed by licensed HelloPharmacist pharmacists — see our data sources and editorial standards.

Pharmacist Counseling Corner

Taking Clay and Diltiazem Together: Common Questions

Is it safe to take Clay with Diltiazem?
We do not list a known interaction between Clay and Diltiazem. That does not guarantee the combination is risk-free, so confirm with your pharmacist or doctor — especially if you take other medications or have a health condition.
Do Clay and Diltiazem have any of the same side effects?
Yes — our sources link each of them separately to 7 of the same effects. That is not an interaction: neither changes how your body handles the other. It does mean that if one of those effects turns up, it can be harder to tell which one is behind it. They are listed on this page with the source behind each.
How was the Clay and Diltiazem combination checked?
Interactions in our licensed database are recorded against drug classes. Diltiazem is filed under 9 classifications, and Clay has documented interactions with 2 drug classes — none of Diltiazem's classifications are among them. A medication can belong to classes beyond those recorded in our dataset, so this describes how the check was run rather than guaranteeing safety.
Does Clay interact with any other medications?
Yes. Clay has 3 documented drug interactions in our database — Diltiazem is simply not one of them. If you take anything else, it is worth checking each one; they are all listed on this page.
Does Diltiazem interact with any supplements?
Yes. Diltiazem has documented interactions with 260 supplements in our database — Clay is not one of them. The Diltiazem interaction page linked on this page lists every one, ranked by severity.

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

Where next

Keep Exploring

Clay monograph Uses, safety profile, and every drug interaction in one place Diltiazem drug information The full plain-English guide to this medication Diltiazem supplement interactions Every supplement checked against Diltiazem, ranked by severity Supplement interaction checker Check any supplement or product against your medications Browse medications A–Z Every drug we’ve checked against herbs & supplements References The 31 citations behind this page Ask a pharmacist Free, personal answer from our licensed team

Still Have a Question About Diltiazem and Clay?

Our pharmacists answer your medication & supplement questions — free.

Ask a pharmacist

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.