Drug & supplement interaction

Quillaia + Felodipine

Felodipine brand names: Plendil, Renedil.

No Known Interaction
Medically reviewed by · Updated July 2026 · Pair last verified Sep 13, 2026
The bottom line No known interaction

We found no known interaction between Quillaia and Felodipine 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 Felodipine 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

Quillaia and Felodipine

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 Felodipine 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 Felodipine and Quillaia? Ask Dr. Brian Staiger, PharmD, BCPS directly ›
How we checked

Why No Interaction Is Listed for Felodipine

Interactions in our licensed database are recorded against drug classes, not just single drug names. Felodipine is filed under 5 classifications — including calcium channel blockers, antihypertensive drugs, cytochrome p450 3a4 (cyp3a4) substrates. Quillaia has documented interactions with 1 drug class — the most serious being immunosuppressants (moderate) — and none of Felodipine’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 — Felodipine isn’t one of them. If you take anything else, check it against the full list below.

Moderate 121 No known interaction 2,709 (incl. Felodipine)
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 Felodipine 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.

    Felodipine

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

  • Diarrhea reported in 7.8% of FDA reports for Felodipine 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.

    Felodipine

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

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

Effects for Felodipine come from the ADVERSE REACTIONS section of its FDA label; effects for Quillaia come from the Natural Medicines adverse-effect record, quoted above. Where a percentage is shown, it is the share of 11,328 voluntary FDA FAERS reports for Felodipine 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

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

How to take them

Some Felodipine Products Have a Food Rule — Quillaia Should Not Break It

At least one FDA label for a product containing Felodipine says to take it on an empty stomach. Most supplements — Quillaia included — are taken with a meal, so the easy mistake is swallowing both together at breakfast. Where that rule applies, keep Felodipine on its own and move Quillaia to a meal later in the day.

This may not be true of your version. Food instructions belong to the product, not the ingredient: two Felodipine 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.

Felodipine should regularly be taken either without food or with a light meal (see CLINICAL PHARMACOLOGY, Pharmacokinetics and Metabolism ).

From the Dosage and Administration section of the FDA label we read for Felodipine — 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.

From our Q&A

Questions About Quillaia or Felodipine

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 Felodipine, 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 Felodipine

This page covers Quillaia only. If you take other supplements — a multivitamin, a sleep aid, something for joints — the Felodipine page lists 232 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: 8 major · 182 moderate · 42 minor.

From our pharmacist’s overview on the Felodipine page

“Felodipine (Plendil) is a blood pressure medicine broken down by the CYP3A4 enzyme, which is why 232 supplements and foods have an interaction on file, eight of them rated major. This list deserves real care.”

Reviewed by 2 · Jul 18, 2026

Open the Felodipine interaction page

How much people look this up

Where Quillaia and Felodipine 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

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

29 days ago today
Medication Felodipine
Steady interest

#1,433 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 13, 2026. The Quillaia and Felodipine 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 Felodipine

What Is Felodipine Used For?

Brand names: Plendil, Renedil

Felodipine extended-release tablets are used to treat high blood pressure (hypertension). Lowering blood pressure reduces the risk of serious events like stroke and heart attack. Felodipine may be used alone or combined with other blood pressure medicines.

Keeping blood pressure under control is part of a broader approach to heart health that can include managing cholesterol, blood sugar, and lifestyle factors like diet, exercise, and not smoking.

Most-Reported Side Effects for Felodipine

From FAERS, the FDA’s public side-effect reporting system (11,328 reports, all brands). Reports are voluntary and are not proof the drug caused the effect.

Fatigue 1,108 reports
Dyspnea 1,002 reports
Dizziness 1,000 reports
Diarrhea 887 reports
Nausea 887 reports
See full Felodipine 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
121 Moderate 2,708 No 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

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

Showing the 60 most looked-up of 2,708 medications checked with no known interaction — see the full Quillaia list.

See the full Quillaia interactions page
See every supplement checked against Felodipine, ranked by severity
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 Felodipine Together: Common Questions

Is it safe to take Quillaia with Felodipine?
We do not list a known interaction between Quillaia and Felodipine. 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 Felodipine 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.
Should I take Quillaia and Felodipine at the same time of day?
At least one FDA label for a product containing Felodipine says to take it on an empty stomach, and supplements are usually taken with a meal — so taking them together at breakfast is the easy mistake. Where that applies, keep Felodipine on its own and move Quillaia to a meal later in the day. Food instructions belong to the product rather than the ingredient, so check the directions on your own box. This is about absorption, not an interaction.
How was the Quillaia and Felodipine combination checked?
Interactions in our licensed database are recorded against drug classes. Felodipine is filed under 5 classifications, and Quillaia has documented interactions with 1 drug class — none of Felodipine'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 — Felodipine 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 Felodipine interact with any supplements?
Yes. Felodipine has documented interactions with 232 supplements in our database — Quillaia is not one of them. The Felodipine 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

Quillaia monograph Uses, safety profile, and every drug interaction in one place Felodipine drug information The full plain-English guide to this medication Felodipine supplement interactions Every supplement checked against Felodipine, 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 5 citations behind this page Ask a pharmacist Free, personal answer from our licensed team

Still Have a Question About Felodipine 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.