Drug & supplement interaction

Dodder + Metronidazole

Metronidazole brand names: Flagyl, Protostat, Metronidazole, Nidazol, Trikacide, and others.

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 Dodder and Metronidazole 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

Dodder and Metronidazole

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 Metronidazole and Dodder 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.

Worth understanding: our licensed dataset holds no drug-interaction record for Dodder at all — not against Metronidazole, and not against any other medication we track. This verdict therefore rests on the absence of any recorded data, not on research that looked at this combination and found nothing. We cannot rule an interaction out.

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.

Dodder safety at a glance

Dodder overall Use caution Human safety data are limited, so use cautiously and under guidance from a healthcare professional.
Pregnancy Avoid Not enough safety information exists, so it is best avoided during pregnancy.
Breastfeeding Avoid There is no reliable safety data, so it is best avoided while breastfeeding.

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

Still wondering about combining Metronidazole and Dodder? Ask Dr. Brian Staiger, PharmD, BCPS directly ›
What to actually watch for

No Interaction Found — But Data Suggests Dodder and Metronidazole 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.

  • Reduced appetite Additional detail

    Dodder

    “Orally, a combination of whey and dodder seed extract has been reported to cause anorexia, mild dyspepsia, and feelings of stomach heaviness. It is not known if these symptoms are related to whey, dodder, or the combination. Intestinal colic and diarrhea have been reported as possible symptoms of dodder overdose. Traditional sources suggest a maximum daily dose of 8 grams of dodder aerial parts.”

    Dodder · Natural Medicines adverse-effect record, reported in anorexia.

    2 sources cited
    1. 99156. Mehrbani M, Choopani R, Fekri A, Mehrabani M, Mosaddegh M, Mehrabani M. The efficacy of whey associated with dodder seed extract on moderate-to-severe atopic dermatitis in adults: A randomized, double-blind, placebo-controlled clinical trial. J Ethnopharm PubMed
    2. 99157. Firoozabadi A, Zarshenas MM, Salehi A, Jahanbin S, Mohagheghzadeh A. Effectiveness of Cuscuta planiflora Ten. and Nepeta menthoides Boiss. & Buhse in major depression: a triple-blind randomized controlled trial study. J Evid Based Complementary Altern Med

    Metronidazole

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

  • Diarrhea reported in 6.5% of FDA reports for Metronidazole Additional detail

    Dodder

    “Orally, dodder is generally well tolerated. High doses may cause intestinal colic and diarrhea (18,99156).”

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

    2 sources cited
    1. 18. Gruenwald J, Brendler T, Jaenicke C. PDR for Herbal Medicines. 1st ed. Montvale, NJ: Medical Economics Company, Inc., 1998.
    2. 99156. Mehrbani M, Choopani R, Fekri A, Mehrabani M, Mosaddegh M, Mehrabani M. The efficacy of whey associated with dodder seed extract on moderate-to-severe atopic dermatitis in adults: A randomized, double-blind, placebo-controlled clinical trial. J Ethnopharm PubMed

    Metronidazole

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

Reported for Dodder but not commonly for Metronidazole: stomach upset.

Effects for Metronidazole come from the ADVERSE REACTIONS section of its FDA label; effects for Dodder come from the Natural Medicines adverse-effect record, quoted above. Where a percentage is shown, it is the share of 64,630 voluntary FDA FAERS reports for Metronidazole 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.

From our Q&A

Questions About Dodder or Metronidazole

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

This page covers Dodder only. If you take other supplements — a multivitamin, a sleep aid, something for joints — the Metronidazole page lists 83 supplements it has a documented interaction with, worst first, each one explained.

The most serious there right now: Activated Charcoal (major), American Hellebore (major), Arsenic (major), Cesium (major) and Ephedra (major).

By severity: 7 major · 63 moderate · 13 minor.

From our pharmacist’s overview on the Metronidazole page

“Metronidazole (Flagyl) can stretch the heart's QT interval on its own, and most of the seven major-rated interactions among its 83 flagged supplement ingredients do the same thing, so I read this list with more wariness than most antibiotics earn. Grapefruit and ephedra stand out for adding to that heart-rhythm risk, while activated ch…”

Reviewed by 2 · Jul 18, 2026

Open the Metronidazole interaction page

One more smart check

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

We hold 1 real supplement products containing Dodder, each one broken down to its full ingredient list — and combination products often carry several ingredients besides Dodder. Even though Dodder itself has no known interaction with Metronidazole, 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 Dodder and Metronidazole 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 Dodder
Top half

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

29 days ago today
Medication Metronidazole
Top 25%

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

What is Dodder?

Dodder
  • Sexual health and impotence
  • Energy and fatigue
  • Kidney and reproductive support (in traditional medicine)
  • Eye health and vision
  • Liver support

Dodder (Cuscuta) is a parasitic plant whose seeds are used in traditional Chinese and Middle Eastern medicine, mainly for sexual, kidney, and energy-related complaints. Human evidence for any of these uses is very limited, and safety has not been well studied, so talk with your pharmacist or doctor before trying it.

Cuscuta chinensis · Convolvulaceae · Seeds (and sometimes the whole vine) · Dried seeds, powders, capsules, tinctures, teas, and ingredients in traditional Chinese herbal formulas

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

Dodder: dosing

There is no well-established, standardized dose of dodder for any health condition. Traditional formulas vary widely, and the strength of commercial products differs from brand to brand.If you choose to use a dodder product, follow the directions on the label and do not exceed the recommended amount.

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

Read the full Dodder monograph & all interactions
Medication

About Metronidazole

What Is Metronidazole Used For?

Brand names: Flagyl, Protostat, Metronidazole, Nidazol, Trikacide, MetroGel, Flagyl IV, Metronidazole Redi-Infusion, Flagyl IV RTU, Metro IV, Anabact, Metrosa, Metrotop, Noritate, Rozex Cream, Rozex Gel, Zyomet, Likmez

Metronidazole treats three main types of infections. It's used for trichomoniasis (a sexually transmitted parasitic infection), amebiasis (an intestinal or liver infection caused by a parasite), and serious anaerobic bacterial infections — infections caused by bacteria that thrive without oxygen, which can affect the abdomen, skin, bones, lungs, and other areas.

Because sexual partners can pass trichomoniasis back and forth, both partners are typically treated at the same time, even if one has no symptoms.

Most-Reported Side Effects for Metronidazole

From FAERS, the FDA’s public side-effect reporting system (64,630 reports, all brands). Reports are voluntary and are not proof the drug caused the effect.

Nausea 4,812 reports
Diarrhea 4,197 reports
Vomiting 3,393 reports
Fever 3,294 reports
Drug hypersensitivity 3,160 reports
See full Metronidazole drug information
Keep checking

Other Drugs & Dodder

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

0Major
0Moderate
0Minor
2,829No known interaction
2,829 No interaction
No interaction 2,829 drugs checked — show the list

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

Showing the 60 most looked-up of 2,829 medications checked with no known interaction — see the full Dodder list.

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

Dodder References

The 3 references that drive our Dodder 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. Gruenwald J, Brendler T, Jaenicke C. PDR for Herbal Medicines. 1st ed. Montvale, NJ: Medical Economics Company, Inc., 1998.
  2. Mehrbani M, Choopani R, Fekri A, Mehrabani M, Mosaddegh M, Mehrabani M. The efficacy of whey associated with dodder seed extract on moderate-to-severe atopic dermatitis in adults: A randomized, double-blind, placebo-controlled clinical trial. J Ethnopharm PubMed
  3. Firoozabadi A, Zarshenas MM, Salehi A, Jahanbin S, Mohagheghzadeh A. Effectiveness of Cuscuta planiflora Ten. and Nepeta menthoides Boiss. & Buhse in major depression: a triple-blind randomized controlled trial study. J Evid Based Complementary Altern Med

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 Dodder and Metronidazole Together: Common Questions

Is it safe to take Dodder with Metronidazole?
We do not list a known interaction between Dodder and Metronidazole. 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 Dodder and Metronidazole have any of the same side effects?
Yes — our sources link each of them separately to 2 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.
Does Metronidazole interact with any supplements?
Yes. Metronidazole has documented interactions with 83 supplements in our database — Dodder is not one of them. The Metronidazole 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

Dodder monograph Uses, safety profile, and every drug interaction in one place Metronidazole drug information The full plain-English guide to this medication Metronidazole supplement interactions Every supplement checked against Metronidazole, 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 3 citations behind this page Ask a pharmacist Free, personal answer from our licensed team

Still Have a Question About Metronidazole and Dodder?

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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.