Drug & supplement interaction

Kaolin + Glycerol Phenylbutyrate

Glycerol Phenylbutyrate brand name: Ravicti.

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 Kaolin and Glycerol Phenylbutyrate 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 label for Glycerol Phenylbutyrate states a food rule worth keeping to, and 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.

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Interaction report

Kaolin and Glycerol Phenylbutyrate

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 Glycerol Phenylbutyrate and Kaolin 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.

Kaolin safety at a glance

Kaolin overall Use caution Generally considered low-risk for short-term use, but long-term or excessive use is not well studied.
Pregnancy Likely Safe When used orally in food amounts. Kaolin has Generally Recognized as Safe (GRAS) status in the US. Read the full pregnancy detail
Breastfeeding Likely 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) — 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 Glycerol Phenylbutyrate and Kaolin? Ask Dr. Brian Staiger, PharmD, BCPS directly ›
How we checked

Why No Interaction Is Listed for Glycerol Phenylbutyrate

Interactions in our licensed database are recorded against drug classes, not just single drug names. Glycerol Phenylbutyrate is filed under a single classification — oral drugs. Kaolin has documented interactions with 4 drug classes — the most serious being clindamycin (cleocin) (moderate), digoxin (lanoxin) (moderate) and quinidine (moderate) — and none of Glycerol Phenylbutyrate’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

Kaolin Does Interact With Other Medications

Kaolin has 7 moderate known drug interactions in our database — Glycerol Phenylbutyrate isn’t one of them. If you take anything else, check it against the full list below.

Moderate 7 No known interaction 2,823 (incl. Glycerol Phenylbutyrate)
Taking anything else?

Check Another of Your Medications Against Kaolin

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

What to actually watch for

No Interaction Found — But Data Suggests Kaolin and Glycerol Phenylbutyrate 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. One of them is worth acting on rather than waiting out — marked below.

  • Anemia Worth acting on Additional detail

    Kaolin

    “Orally, kaolin can cause constipation, particularly in children and the elderly (15). 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.”

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

    4 sources cited
    1. 15. McEvoy GK, ed. AHFS Drug Information. Bethesda, MD: American Society of Health-System Pharmacists, 1998.
    2. 101216. 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. PubMed
    3. 101218. 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. PubMed
    4. 105862. Attarha BO, Mikulic S, Harris C, Scolapio JS. Kaolin Clay Anemia. Cureus 2021;13(3):e13796.

    Glycerol Phenylbutyrate

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

  • Constipation Additional detail

    Kaolin

    “Orally, kaolin can cause constipation, particularly in children and the elderly (15). It can also cause intestinal obstruction. After inhalation, kaolin may cause occupational kalinosis (pulmonary disease).”

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

    5 sources cited
    1. 15. McEvoy GK, ed. AHFS Drug Information. Bethesda, MD: American Society of Health-System Pharmacists, 1998.
    2. 101216. 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. PubMed
    3. 195. Levin JL, Frank AL, Williams MG, et al. Kaolinosis in a cotton mill worker. Am J Ind Med 1996;29:215-21.
    4. 196. Chaudhary BA, Kanes GJ, Pool WH. Pleural thickening in mild kaolinosis. South Med J 1997;90:1106-9.
    5. 197. Altekruse EB, Chaudhary BA, Pearson MG, Morgan WK. Kaolin dust concentrations and pneumoconiosis at a kaolin mine. Thorax 1984;39:436-41.

    Glycerol Phenylbutyrate

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

  • Stomach pain / Dizziness / Headache reported in 4.9% of FDA reports for Glycerol Phenylbutyrate Additional detail

    Kaolin

    Recorded for Kaolin in the same Natural Medicines adverse-effect record shown under Anemia above.

    Glycerol Phenylbutyrate

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

Reported for Kaolin but not commonly for Glycerol Phenylbutyrate: a bowel blockage and fainting.

Effects for Glycerol Phenylbutyrate come from the ADVERSE REACTIONS section of its FDA label; effects for Kaolin come from the Natural Medicines adverse-effect record, quoted above. Where a percentage is shown, it is the share of 1,358 voluntary FDA FAERS reports for Glycerol Phenylbutyrate 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

Kaolin in Pregnancy & Breastfeeding

Pregnancy And Lactation Likely Safe

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

Pregnancy And Lactation Possibly Safe

When used orally as kaolin-pectin in appropriate amounts.

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

How to take them

Some Glycerol Phenylbutyrate Products Have a Food Rule — Kaolin Should Not Break It

At least one FDA label for a product containing Glycerol Phenylbutyrate says to take it with food. If you take Kaolin on an empty stomach out of habit, keep them separate — and take Glycerol Phenylbutyrate with a meal where the label says to.

This may not be true of your version. Food instructions belong to the product, not the ingredient: two Glycerol Phenylbutyrate products can carry different directions, and extended-release forms often differ from immediate-release ones. The label we read is quoted below — check the directions on your own box or bottle, or ask your pharmacist, for how to take the exact product you were given.

Instruct patients to take glycerol phenylbutyrate oral liquid with food or formula and to administer directly into the mouth via oral syringe.

From the Dosage and Administration section of the FDA label we read for Glycerol Phenylbutyrate — where that label names a specific product, the instruction is that product's. Read the label on DailyMed ›

A food rule is not an interaction — it is about how much of the medicine you absorb. The directions that came with your own product, and your pharmacist, outrank anything on this page.

Everything else you take

See Every Supplement That Interacts With Glycerol Phenylbutyrate

This page covers Kaolin only. If you take other supplements — a multivitamin, a sleep aid, something for joints — the Glycerol Phenylbutyrate page lists 17 supplements it has a documented interaction with, worst first, each one explained.

The most serious there right now: Activated Charcoal (major), Coffee Charcoal (moderate), European Mandrake (moderate), Glucomannan (moderate) and Guar Gum (moderate).

By severity: 1 major · 7 moderate · 9 minor.

From our pharmacist’s overview on the Glycerol Phenylbutyrate page

“Ravicti (glycerol phenylbutyrate) pulls ammonia out of the blood in people with urea cycle disorders, so a dose that never gets absorbed is not a small problem, it can let ammonia climb toward dangerous levels. That is why this list deserves real attention even though it is short.”

Reviewed by 2 · Jul 18, 2026

Open the Glycerol Phenylbutyrate interaction page

How much people look this up

Where Kaolin and Glycerol Phenylbutyrate 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 Kaolin
Steady interest

#1,047 of 1,452 supplements looked up here in the last 7 days

29 days ago today
Medication Glycerol Phenylbutyrate
Top 10%

#193 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 Kaolin reference on this page ↓
  • Freshness: we automatically re-check this combination every week — this pair was last verified September 20, 2026. The Kaolin and Glycerol Phenylbutyrate records this page draws on were last updated July 10, 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 Kaolin

What is Kaolin?

Kaolin
  • Diarrhea
  • Upset stomach and nausea
  • Skincare and facial masks
  • Soothing minor skin irritation
  • Excessive salivation (traditional)

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.

Mineral clay (hydrated aluminum silicate) · Oral suspensions, tablets, powders, topical pastes and masks

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

Kaolin: 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.

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

Read the full Kaolin monograph & all interactions
Medication

About Glycerol Phenylbutyrate

What Is Glycerol Phenylbutyrate Used For?

Brand name: Ravicti

Glycerol phenylbutyrate oral liquid — available as the brand Ravicti and as a generic — is used for the long-term (chronic) management of urea cycle disorders (UCDs). UCDs are rare inherited conditions where the body cannot properly convert ammonia into urea, causing toxic ammonia levels to build up in the blood and brain.

It is used in patients whose ammonia cannot be controlled by a low-protein diet and/or amino acid supplements alone. It must always be used alongside dietary protein restriction and, in some cases, additional dietary supplements such as essential amino acids, arginine, or citrulline. It is not for treating a sudden, severe spike in ammonia (acute hyperammonemia), and its safety and effectiveness for N-acetylglutamate synthase (NAGS) deficiency have not been established.

Most-Reported Side Effects for Glycerol Phenylbutyrate

From FAERS, the FDA’s public side-effect reporting system (1,358 reports, all brands). Reports are voluntary and are not proof the drug caused the effect.

Ammonia increased 197 reports
Vomiting 165 reports
Hyperammonaemia 158 reports
Decreased appetite 104 reports
Nausea 74 reports
See full Glycerol Phenylbutyrate drug information
Keep checking

Other Drugs & Kaolin

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

0Major
7Moderate
0Minor
2,822No known interaction
7 Moderate 2,822 No interaction
Moderate

7 interactions

No interaction 2,822 drugs checked — show the list

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

Showing the 60 most looked-up of 2,822 medications checked with no known interaction — see the full Kaolin list.

See the full Kaolin interactions page
See every supplement checked against Glycerol Phenylbutyrate, ranked by severity
Evidence & sources

Kaolin References

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

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 Kaolin and Glycerol Phenylbutyrate Together: Common Questions

Is it safe to take Kaolin with Glycerol Phenylbutyrate?
We do not list a known interaction between Kaolin and Glycerol Phenylbutyrate. 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 Kaolin and Glycerol Phenylbutyrate have any of the same side effects?
Yes — our sources link each of them separately to 5 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.
Should I take Kaolin and Glycerol Phenylbutyrate at the same time of day?
At least one FDA label for a product containing Glycerol Phenylbutyrate says to take it with food. If you take Kaolin on an empty stomach out of habit, keep them separate and take Glycerol Phenylbutyrate with a meal where the label says to. Food instructions belong to the product rather than the ingredient — two Glycerol Phenylbutyrate products can differ — so check the directions on your own box. This is about absorption, not an interaction.
How was the Kaolin and Glycerol Phenylbutyrate combination checked?
Interactions in our licensed database are recorded against drug classes. Glycerol Phenylbutyrate is filed under 1 classification, and Kaolin has documented interactions with 4 drug classes — none of Glycerol Phenylbutyrate'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 Kaolin interact with any other medications?
Yes. Kaolin has 7 documented drug interactions in our database — Glycerol Phenylbutyrate 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 Glycerol Phenylbutyrate interact with any supplements?
Yes. Glycerol Phenylbutyrate has documented interactions with 17 supplements in our database — Kaolin is not one of them. The Glycerol Phenylbutyrate 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

Kaolin monograph Uses, safety profile, and every drug interaction in one place Glycerol Phenylbutyrate drug information The full plain-English guide to this medication Glycerol Phenylbutyrate supplement interactions Every supplement checked against Glycerol Phenylbutyrate, 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 18 citations behind this page Ask a pharmacist Free, personal answer from our licensed team

Still Have a Question About Glycerol Phenylbutyrate and Kaolin?

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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.