Drug & supplement interaction

Clay + Quinine

Quinine brand name: Qualaquin.

Moderate Interaction
Medically reviewed by · Updated September 2026
The bottom line Moderate

Clay has a moderate interaction with Quinine. In vitro evidence suggests that consuming clay reduces the bioavailability of quinine by about 30%.

Read the full interaction report
SeverityModerate
LikelihoodProbable
EvidenceD
What do Severity, Likelihood & Evidence mean?
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Interaction report

Clay and Quinine

Here is the interaction we found between these two, with the evidence behind it.

Moderate

QUININE

In vitro evidence suggests that consuming clay reduces the bioavailability of quinine by about 30%. Theoretically, consumption of clay along with quinine might reduce the effectiveness of quinine therapy.
Severity Moderate Likelihood Probable Evidence D

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..

Dr. Brian Staiger, PharmD, BCPS
Dr. Brian Staiger explains PharmD, Clinical Pharmacist

Here's the simple version: clay taken by mouth acts like a sponge in your gut. It has a huge surface area that grabs onto water, oils, and other molecules, and that includes medications. Lab studies suggest that swallowing clay can bind to quinine and cut how much your body actually absorbs by roughly 30%. Quinine isn't a prodrug, so less absorption simply means less drug reaching your bloodstream.

Since quinine is treating malaria, a serious infection, getting too little is a real concern. Weaker treatment could let the infection linger or come back. This finding so far is only from lab work, not people, so think of it as a caution rather than a proven problem. To be safe, don't take clay around the same time as your quinine, and check with your pharmacist or doctor first.

Contact Dr. Brian directly if you have additional questions on this interaction
References
  1. Dominy NJ, Davoust E, Minekus M. Adaptive function of soil consumption: an in vitro study modeling the human stomach and small intestine. J Exp Biol 2004;207(Pt 2):319-24.

What These Ratings Mean

Every interaction above is graded three ways — here’s the key to each label.

Severity how clinically significant the interaction is
Major

Clinically significant. Avoid the combination, or use only under close professional supervision.

Moderate

Usually worth avoiding or managing — may need monitoring, a dose change, or timing apart.

Minor

Generally not serious. Be aware of it and mention it to your pharmacist.

Likelihood how strong the evidence is that the interaction actually happens in people
  • LikelyWell-controlled human studies have demonstrated the likely existence of this interaction.
  • ProbableInteraction 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.
  • PossibleInteraction 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.
  • UnlikelyInteraction has been demonstrated in animal or in lab research but has been shown not to occur in humans.
Evidence the quality of the studies behind the rating (graded A–D)
  • AHigh-quality meta-analysis (quantitative systematic review).
  • BCase-control study.
  • CConsensus.
  • DAnecdotal evidence.

These ratings are for information only. Never start, stop, or otherwise change your therapy before speaking with your provider.

Keep it in perspective

Clay Also Interacts With Other Medications

Clay has 2 moderate known drug interactions in our database — the Quinine one above is one of them. If you take anything else, check it against the full list below.

Moderate 2 No known interaction 2,828 (incl. Quinine)
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.

From our Q&A

Questions About Clay or Quinine

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 Quinine, 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 Quinine

This page covers Clay only. If you take other supplements — a multivitamin, a sleep aid, something for joints — the Quinine page lists 175 supplements it has a documented interaction with, worst first, each one explained.

The most serious there right now: Activated Charcoal (major), Cinchona (major), Foxglove (major), Grapefruit (major) and Lily-of-the-valley (major).

By severity: 9 major · 125 moderate · 41 minor.

From our pharmacist’s overview on the Quinine page

“Quinine (Qualaquin) earns a genuine pause before you add any supplement, because nine of its 175 interacting ingredients are rated major, and two are as everyday as grapefruit and St. John's wort.”

Reviewed by 2 · Jul 18, 2026

Open the Quinine 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. Your product may carry other ingredients that interact with Quinine too, on top of Clay — and those would not show on this page. Find your product and we’ll check every ingredient on its label:

How much people look this up

Where Clay and Quinine 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

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

29 days ago today
Medication Quinine
Top half

#1,297 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.

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.

Read the full Clay monograph & all interactions
Medication

About Quinine

What Is Quinine Used For?

Brand name: Qualaquin

Quinine sulfate capsules (Qualaquin, Quinine Sulfate) are approved only to treat uncomplicated malaria caused by the parasite Plasmodium falciparum. They have been shown to work in regions where the parasite has become resistant to chloroquine.

They are not approved for severe or complicated malaria, for preventing malaria, or for treating or preventing nighttime leg cramps.

See full Quinine 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
2Moderate
0Minor
2,827No known interaction
2 Moderate 2,827 No interaction
Moderate

2 interactions

No interaction 2,827 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 2,827 medications checked with no known interaction — see the full Clay list.

See the full Clay interactions page
See every supplement checked against Quinine, ranked by severity
Sources

Sources & How We Checked

Interaction details are evidence-graded and sourced from the Natural Medicines database. The medication overview comes from MedlinePlus.

Content is written and reviewed by licensed HelloPharmacist pharmacists. See our data sources and editorial standards for how this information is built and checked.

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

Keep exploring
Clay monograph › Uses, safety, and every drug interaction in one place Quinine supplement interactions › Every supplement checked against Quinine, ranked by severity Quinine drug information › The full plain-English guide to this medication Supplement interaction checker › Check any supplement or product against your medications Browse medications A–Z › Every drug we've checked against herbs & supplements Ask a pharmacist › Free, personal answer from our licensed team
Pharmacist Counseling Corner

Taking Clay and Quinine Together: Common Questions

Can you take Clay with Quinine?
There is a moderate interaction, so it may be acceptable with monitoring or timing changes — but check with your pharmacist first. Read the full details on this page and confirm with your pharmacist before combining them.
How serious is the Clay and Quinine interaction?
We rate it Moderate. This combination may require monitoring, a dose adjustment, or separating the times you take each one. Consult your pharmacist before using them together.

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

Still Have a Question About Quinine and Clay?

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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.