Drug & supplement interaction

Gardenia + Metolazone

Metolazone brand names: Diulo, Zaroxolyn, Mykrox.

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 Gardenia and Metolazone 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

Gardenia and Metolazone

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 Metolazone and Gardenia 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.

Gardenia safety at a glance

Gardenia overall Use caution Human safety data are limited, and large or long-term amounts have not been well studied.
Pregnancy Avoid Not enough safety information is available, so it is best to avoid it during pregnancy.
Breastfeeding Avoid There is not enough safety information, so avoid it while breastfeeding.

Safety guidance is general; always confirm with your pharmacist or doctor for your situation.

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

Why No Interaction Is Listed for Metolazone

Interactions in our licensed database are recorded against drug classes, not just single drug names. Metolazone is filed under 5 classifications — including thiazide diuretics, diuretic drugs, antihypertensive drugs. Gardenia has documented interactions with 1 drug class — the most serious being stimulant laxatives (moderate) — and none of Metolazone’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

Gardenia Does Interact With Other Medications

Gardenia has 21 moderate known drug interactions in our database — Metolazone isn’t one of them. If you take anything else, check it against the full list below.

Moderate 21 No known interaction 2,809 (incl. Metolazone)
Taking anything else?

Check Another of Your Medications Against Gardenia

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

What to actually watch for

No Interaction Found — But Data Suggests Gardenia and Metolazone 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 pain / Nausea / Vomiting reported in 6.8% of FDA reports for Metolazone Additional detail

    Gardenia

    “Orally, there are case reports of mesenteric phlebosclerosis, a thickening of the walls of the intestine and mesenteric veins, which can lead to obstruction and occlusion. Typical presenting symptoms are paroxysmal abdominal pain with nausea and vomiting, and imaging studies reveal thickening and stiffening of the walls of the ascending and transverse colon, with dark purple discoloration of the colonic and rectal mu…”

    Gardenia · Natural Medicines adverse-effect record, reported in nausea and vomiting.

    1 source cited
    1. 112954. Tong T, Fu J, Kong Y. Recurrent Abdominal Pain in a 61-Year-Old Woman. Gastroenterology 2023;164(6):887-890. PubMed

    Metolazone

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

  • A skin rash Additional detail

    Gardenia

    “Topically, exposure to gardenia fruit extract or the whole plant has been associated with allergic contact dermatitis.

    Orally, there is a case report of blue-gray skin pigmentation associated with taking a product containing the extracts of gardenia fruit, phellodendron bark, and licorice for 7 years in a 77-year-old female.”

    Gardenia · Natural Medicines adverse-effect record, reported in dermatitis.

    3 sources cited
    1. 26518. Kubo, Y., Nonaka, S., and Yoshida, H. Allergic contact dermatitis from gardenia fruit. Contact Dermatitis 1990;22(2):65-7. PubMed
    2. 49078. Paulsen, E., Skov, P. S., and Andersen, K. E. Immediate skin and mucosal symptoms from pot plants and vegetables in gardeners and greenhouse workers. Contact Dermatitis 1998;39(4):166-170. PubMed
    3. 102698. Mizawa M, Andoh T, Shimizu T. Gardenia fruit-related blue-gray skin pigmentation. JAMA Dermatol. 2020. PubMed

    Metolazone

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

Effects for Metolazone come from the ADVERSE REACTIONS section of its FDA label; effects for Gardenia come from the Natural Medicines adverse-effect record, quoted above. Where a percentage is shown, it is the share of 11,176 voluntary FDA FAERS reports for Metolazone 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.

Overlapping uses

What Metolazone Is Prescribed For, and What Gardenia Has Been Studied For

These two come up together because they touch the same health topic — not because they do the same job. Metolazone is a prescription medicine with approved uses on its FDA label. Gardenia is a supplement: what follows is what researchers have looked at it for, and how strong that evidence is.

Metolazone is prescribed for: Metolazone tablets are used to treat edema (excess fluid buildup) linked to congestive heart failure or kidney diseases — including nephrotic syndrome and conditions with reduced kidney function. They are also used to treat high blood pressure (hypertension), either alone or alongside other blood pressure medications. Metolazone tablets may also be used during pregnancy when edema is caused by a medical condition rather than normal pregnancy changes — but routine use in otherwise healthy pregnant women is not appropriate.

Gardenia has been studied for:

  • Hypertension studied, not established Gardenia has been studied for this. Natural Medicines rates the evidence: Insufficient Reliable Evidence To Rate Read what the research shows

    Gardenia for hypertension

    Although there has been interest in using oral gardenia for hypertension, there is insufficient reliable information about the clinical effects of gardenia for this purpose.

Effectiveness ratings and the research summaries above are the verbatim record from the Natural Medicines database, which grades evidence from “Effective” down to “Insufficient Reliable Evidence To Rate”. A rating below the top of that scale means researchers have looked at it — not that it works, and never that it can stand in for a prescribed medicine. Do not stop or replace Metolazone on your own; if you are taking Gardenia for the same health topic, tell your prescriber, especially if the medicine is being adjusted to a target.

Everything else you take

See Every Supplement That Interacts With Metolazone

This page covers Gardenia only. If you take other supplements — a multivitamin, a sleep aid, something for joints — the Metolazone page lists 222 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), Dolomite (major) and Lithium (major).

By severity: 8 major · 190 moderate · 24 minor.

Open the Metolazone interaction page

One more smart check

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

We hold 240 real supplement products containing Gardenia, each one broken down to its full ingredient list — and combination products often carry several ingredients besides Gardenia. Even though Gardenia itself has no known interaction with Metolazone, 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 Gardenia and Metolazone 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 Gardenia
Steady interest

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

29 days ago today
Medication Metolazone
Steady interest

#1,457 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 Gardenia reference on this page ↓
  • Freshness: we automatically re-check this combination every week — this pair was last verified September 13, 2026. The Gardenia and Metolazone 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 Gardenia

What is Gardenia?

Gardenia
  • Liver and digestive complaints
  • Fever and inflammation
  • Anxiety, restlessness, and trouble sleeping
  • Blood pressure and blood sugar support (traditional)
  • Natural food and fabric coloring

Gardenia fruit has a long history in traditional Chinese medicine and is also used as a natural food coloring. While early lab and animal studies are interesting, strong human evidence for its health benefits is lacking, so talk with your pharmacist or doctor before using it as a supplement.

Gardenia jasminoides · Rubiaceae · Fruit (the dried ripe fruit, called zhi zi in Chinese medicine), and sometimes the flower · Dried fruit, powders, capsules, teas/decoctions, liquid extracts, and as a natural food coloring (gardenia yellow/blue)

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

Gardenia: dosing

There is no standardized, well-established dose for gardenia supplements. Traditional formulas use the dried fruit in decoctions, but products sold today vary widely in strength and form.If you choose to use a gardenia product, follow the directions on the label and do not exceed the recommended amount.

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

Read the full Gardenia monograph & all interactions
Medication

About Metolazone

What Is Metolazone Used For?

Brand names: Diulo, Zaroxolyn, Mykrox

Metolazone tablets are used to treat edema (excess fluid buildup) linked to congestive heart failure or kidney diseases — including nephrotic syndrome and conditions with reduced kidney function. They are also used to treat high blood pressure (hypertension), either alone or alongside other blood pressure medications.

Metolazone tablets may also be used during pregnancy when edema is caused by a medical condition rather than normal pregnancy changes — but routine use in otherwise healthy pregnant women is not appropriate.

Most-Reported Side Effects for Metolazone

From FAERS, the FDA’s public side-effect reporting system (11,176 reports, all brands). Reports are voluntary and are not proof the drug caused the effect.

Dyspnea 1,247 reports
Acute kidney injury 799 reports
Nausea 761 reports
Renal failure 716 reports
Cardiac failure congestive 683 reports
See full Metolazone drug information
Keep checking

Other Drugs & Gardenia

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

0Major
21Moderate
0Minor
2,808No known interaction
21 Moderate 2,808 No interaction
Moderate

21 interactions

No interaction 2,808 drugs checked — show the list

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

Showing the 60 most looked-up of 2,808 medications checked with no known interaction — see the full Gardenia list.

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

Gardenia References

The 5 references that drive our Gardenia 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. Kubo, Y., Nonaka, S., and Yoshida, H. Allergic contact dermatitis from gardenia fruit. Contact Dermatitis 1990;22(2):65-7. PubMed
  2. Yamauchi, K., Fujimoto, N., Kuwano, S., Inouye, H., and Inoue, K. The mechanism of purgative action of geniposide, an iridoid glucoside of the fruit of Gardenia, in mice. Planta Med 1976;30(1):39-47.
  3. Paulsen, E., Skov, P. S., and Andersen, K. E. Immediate skin and mucosal symptoms from pot plants and vegetables in gardeners and greenhouse workers. Contact Dermatitis 1998;39(4):166-170. PubMed
  4. Mizawa M, Andoh T, Shimizu T. Gardenia fruit-related blue-gray skin pigmentation. JAMA Dermatol. 2020. PubMed
  5. Tong T, Fu J, Kong Y. Recurrent Abdominal Pain in a 61-Year-Old Woman. Gastroenterology 2023;164(6):887-890. 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 Gardenia and Metolazone Together: Common Questions

Is it safe to take Gardenia with Metolazone?
We do not list a known interaction between Gardenia and Metolazone. 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 Gardenia and Metolazone have any of the same side effects?
Yes — our sources link each of them separately to 4 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.
Are Gardenia and Metolazone used for the same thing?
They overlap in purpose, which usually means the real question is whether you need both rather than whether they are safe together. This page lists the shared uses and how strong the evidence is for Gardenia in each. That is a conversation for your prescriber, especially if Metolazone is being adjusted to a target.
How was the Gardenia and Metolazone combination checked?
Interactions in our licensed database are recorded against drug classes. Metolazone is filed under 5 classifications, and Gardenia has documented interactions with 1 drug class — none of Metolazone'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 Gardenia interact with any other medications?
Yes. Gardenia has 21 documented drug interactions in our database — Metolazone 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 Metolazone interact with any supplements?
Yes. Metolazone has documented interactions with 222 supplements in our database — Gardenia is not one of them. The Metolazone 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

Gardenia monograph Uses, safety profile, and every drug interaction in one place Metolazone drug information The full plain-English guide to this medication Metolazone supplement interactions Every supplement checked against Metolazone, 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 Metolazone and Gardenia?

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.