Drug & supplement interaction

Quillaia + Ketoconazole

Ketoconazole brand name: Nizoral.

No Known Interaction
The bottom line No known interaction

We found no known interaction between Quillaia and Ketoconazole 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.

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Interaction report

Quillaia and Ketoconazole

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 Ketoconazole and Quillaia 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.

Quillaia safety at a glance

Quillaia overall Use caution Generally recognized as safe in the small amounts used in foods, but larger or concentrated doses may be harmful.
Pregnancy Possibly Unsafe When used in medicinal amounts; avoid using. Read the full pregnancy detail
Breastfeeding Possibly Unsafe When used in medicinal amounts; avoid using. 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 Ketoconazole and Quillaia? Ask Dr. Brian Staiger, PharmD, BCPS directly ›
How we checked

Why No Interaction Is Listed for Ketoconazole

Interactions in our licensed database are recorded against drug classes, not just single drug names. Ketoconazole is filed under 8 classifications — including antifungals, cytochrome p450 2c19 (cyp2c19) inhibitors, cytochrome p450 2c9 (cyp2c9) inhibitors. Quillaia has documented interactions with 1 drug class — the most serious being immunosuppressants (moderate) — and none of Ketoconazole’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

Quillaia Does Interact With Other Medications

Quillaia has 121 moderate known drug interactions in our database — Ketoconazole isn’t one of them. If you take anything else, check it against the full list below.

Taking anything else?

Check Another of Your Medications Against Quillaia

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

What to actually watch for

No Interaction Found — But Data Suggests Quillaia and Ketoconazole 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.

  • Stomach upset / Stomach pain Additional detail

    Quillaia

    “Orally, large amounts of quillaia are associated with diarrhea, stomach pain, and other gastrointestinal disturbances. Quillaia powder can be caustic to esophageal and gastrointestinal mucosae (12).”

    Quillaia · Natural Medicines adverse-effect record, reported in diarrhea.

    1 source cited
    1. 12. McGuffin M, Hobbs C, Upton R, Goldberg A, eds. American Herbal Products Association's Botanical Safety Handbook. Boca Raton, FL: CRC Press, LLC 1997.

    Ketoconazole

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

  • Diarrhea Additional detail

    Quillaia

    “Orally, quillaia seems to be well tolerated when consumed in foods; however, it is associated with significant adverse effects at higher doses due to its oxalate and tannin content. A thorough evaluation of safety outcomes has not been conducted.

    Serious Adverse Effects (Rare):

    Orally: Coma, convulsions, diarrhea, gastrointestinal tract mucosal damage, hemolysis, and kidney failure.”

    Quillaia · Natural Medicines adverse-effect record, reported in diarrhea.

    Ketoconazole

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

Reported for Quillaia but not commonly for Ketoconazole: kidney problems and seizures.

Effects for Ketoconazole come from the ADVERSE REACTIONS section of its FDA label; effects for Quillaia come from the Natural Medicines adverse-effect record, quoted above. Wording is matched across sources by our own clinical vocabulary, so treat this as a prompt to pay attention, not a diagnosis.

Special populations

Quillaia in Pregnancy & Breastfeeding

Pregnancy And Lactation Possibly Unsafe

When used in medicinal amounts; avoid using.

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 Quillaia or Ketoconazole

These are real questions from readers, answered by the pharmacists at HelloPharmacist — written by a person, not generated from a database. Each one covers Quillaia or Ketoconazole, 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 Ketoconazole

This page covers Quillaia only. If you take other supplements — a multivitamin, a sleep aid, something for joints — the Ketoconazole page lists 182 supplements it has a documented interaction with, worst first, each one explained.

The most serious there right now: Activated Charcoal (major), Beer (major), Grapefruit (major), Siberian Cocklebur (major) and St. John's Wort (major).

By severity: 6 major · 135 moderate · 41 minor.

From our pharmacist’s overview on the Ketoconazole page

“Ketoconazole (Nizoral) is already hard on the liver, so treat its 182 interacting supplements with genuine care, starting with the six rated major. Most of the list runs through CYP3A4, the liver enzyme ketoconazole strongly blocks, so it can raise levels of over a hundred herbal ingredients, while grapefruit pushes ketoconazole itself…”

Reviewed by 2 · Jul 18, 2026

Open the Ketoconazole interaction page

How much people look this up

Where Quillaia and Ketoconazole 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 Quillaia
Steady interest

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

29 days ago today
Medication Ketoconazole
Steady interest

#1,833 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 Quillaia reference on this page ↓
  • Freshness: we automatically re-check this combination every week — this pair was last verified September 20, 2026. The Quillaia and Ketoconazole 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 Quillaia

What is Quillaia?

  • Cough and chest congestion
  • Foaming agent in beverages
  • Vaccine adjuvant (in pharmaceutical manufacturing)
  • Washing and cleansing (traditional soap)
  • Skin conditions

Quillaia (soap bark tree) is a plant whose bark contains foaming compounds called saponins, and it is widely used as an emulsifier in foods and drinks. As a supplement or herbal remedy its benefits are not well proven, and large amounts can be irritating or toxic, so it should be used cautiously and only as directed.

Quillaja saponaria · Quillajaceae · Inner bark · Liquid extract, powder, food and beverage additive, tinctures

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

Quillaia: dosing

There is no well-established standardized supplement dose for quillaia. The amounts used as a food and beverage additive are tightly limited by safety regulations.If you choose to use a quillaia product, follow the directions on the label and do not exceed the recommended amount.

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

Read the full Quillaia monograph & all interactions
Medication

About Ketoconazole

What Is Ketoconazole Used For?

Brand name: Nizoral

Ketoconazole 2% shampoo and foam are used to treat tinea versicolor (also called pityriasis versicolor) — a fungal infection caused by Pityrosporum orbiculare (also known as Malassezia furfur), a yeast that naturally lives on the skin.

This infection creates light or dark patches, most often on the trunk, neck, arms, and upper thighs. Even after the fungus is cleared, those skin patches may take months to return to their normal color — that's normal, and depends on your skin type and sun exposure. Tinea versicolor can also come back, since the fungus lives on healthy skin even when there's no active infection.

Most-Reported Side Effects for Ketoconazole

From FAERS, the FDA’s public side-effect reporting system (0 reports, all brands). Reports are voluntary and are not proof the drug caused the effect.

Pruritus 984 reports
Fatigue 975 reports
Nausea 873 reports
Rash 858 reports
Diarrhea 814 reports
See full Ketoconazole drug information
Keep checking

Other Drugs & Quillaia

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

0Major
121Moderate
0Minor
2,708No known interaction
Moderate

121 interactions

Showing 60 of 121 moderate interactions — see all 121 on the Quillaia page.

No interaction 2,708 drugs checked — show the list
Evidence & sources

Quillaia References

The 5 references that drive our Quillaia 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. The Review of Natural Products by Facts and Comparisons. St. Louis, MO: Wolters Kluwer Co., 1999.
  2. Leung AY, Foster S. Encyclopedia of Common Natural Ingredients Used in Food, Drugs and Cosmetics. 2nd ed. New York, NY: John Wiley & Sons, 1996.
  3. McGuffin M, Hobbs C, Upton R, Goldberg A, eds. American Herbal Products Association's Botanical Safety Handbook. Boca Raton, FL: CRC Press, LLC 1997.
  4. Wu JY, Gardner BH, Murphy CI, et al. Saponin adjuvant enhancement of antigen-specific immune responses to an experimental HIV-1 vaccine. J Immunol 1992;148:1519-25. DOI
  5. Fleck JD, Betti AH, da Silva FP, et al. Saponins from Quillaja saponaria and Quillaja brasiliensis: particular chemical characteristics and biological activities. Molecules 2019;24(1). pii: E171. PubMed

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 Quillaia and Ketoconazole Together: Common Questions

Is it safe to take Quillaia with Ketoconazole?
We do not list a known interaction between Quillaia and Ketoconazole. 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 Quillaia and Ketoconazole have any of the same side effects?
Yes — our sources link each of them separately to 3 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 Quillaia and Ketoconazole combination checked?
Interactions in our licensed database are recorded against drug classes. Ketoconazole is filed under 8 classifications, and Quillaia has documented interactions with 1 drug class — none of Ketoconazole'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 Quillaia interact with any other medications?
Yes. Quillaia has 121 documented drug interactions in our database — Ketoconazole 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 Ketoconazole interact with any supplements?
Yes. Ketoconazole has documented interactions with 182 supplements in our database — Quillaia is not one of them. The Ketoconazole interaction page linked on this page lists every one, ranked by severity.

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

Still Have a Question About Ketoconazole and Quillaia?

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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.