Drug & supplement interaction

White Mustard + Metoprolol

Metoprolol brand names: Lopressor, Toprol XL.

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 White Mustard and Metoprolol 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 Metoprolol 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

White Mustard and Metoprolol

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 Metoprolol and White Mustard 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 White Mustard at all — not against Metoprolol, 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.

White Mustard safety at a glance

White Mustard overall Use caution Generally safe as a food, but concentrated seed products and topical applications can irritate skin and the stomach.
Pregnancy Likely Unsafe When used orally in medicinal amounts. White mustard is thought to have abortifacient and menstrual-stimulant properties. Read the full pregnancy detail
Breastfeeding Use caution Food amounts are likely fine, but medicinal amounts lack safety data, so use caution.

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 Metoprolol and White Mustard? Ask Dr. Brian Staiger, PharmD, BCPS directly ›
What to actually watch for

No Interaction Found — But Data Suggests White Mustard and Metoprolol 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.

  • Itching / A skin rash Additional detail

    White Mustard

    “Orally and topically, white mustard can cause allergic responses. Topically, white mustard can result in allergic contact dermatitis. Symptoms including spreading itching, red, and burning lesions have been observed on the skin of a 48-year-old woman approximately one week after she used a topical Chinese herbal medicine patch consisting of white mustard seed, licorice, ginger, corydalis, and asarabacca.”

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

    2 sources cited
    1. 101057. Li J, Jin HZ. Allergic contact dermatitis caused by Chinese herbal medicine, white mustard seed. J Dermatol. 2013;40(1):69-70.
    2. 101058. Vereda A, Sirvent S, Villalba M, Rodríguez R, Cuesta-Herranz J, Palomares O. Improvement of mustard (Sinapis alba) allergy diagnosis and management by linking clinical features and component-resolved approaches. J Allergy Clin Immunol. 2011;127(5):1304-7. PubMed

    Metoprolol

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

Effects for Metoprolol come from the ADVERSE REACTIONS section of its FDA label; effects for White Mustard 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

White Mustard in Pregnancy & Breastfeeding

Pregnancy Likely Unsafe

When used orally in medicinal amounts. White mustard is thought to have abortifacient and menstrual-stimulant properties.

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 Metoprolol Products Have a Food Rule — White Mustard Should Not Break It

At least one FDA label for a product containing Metoprolol says to take it with food. If you take White Mustard on an empty stomach out of habit, keep them separate — and take Metoprolol 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 Metoprolol 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.

Administer once daily with food or after a meal.

From the Dosage and Administration section of the FDA label we read for Metoprolol — 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 White Mustard or Metoprolol

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

This page covers White Mustard only. If you take other supplements — a multivitamin, a sleep aid, something for joints — the Metoprolol page lists 183 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), Indian Snakeroot (major) and Tyramine (major).

By severity: 5 major · 152 moderate · 26 minor.

From our pharmacist’s overview on the Metoprolol page

“With metoprolol (Lopressor, Toprol XL), a beta-blocker for high blood pressure and heart problems, these interactions deserve genuine care, starting with the five rated major. Most entries pull blood pressure one way or the other: many supplements add to metoprolol's lowering effect and can drop pressure too far, while a few, tyramine…”

Reviewed by 2 · Jul 18, 2026

Open the Metoprolol interaction page

One more smart check

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

We hold 13 real supplement products containing White Mustard, each one broken down to its full ingredient list — and combination products often carry several ingredients besides White Mustard. Even though White Mustard itself has no known interaction with Metoprolol, 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 White Mustard and Metoprolol 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 White Mustard
Steady interest

#1,377 of 1,452 supplements looked up here in the last 7 days

29 days ago today
Medication Metoprolol
Top 10

#7 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 White Mustard reference on this page ↓
  • Freshness: we automatically re-check this combination every week — this pair was last verified September 13, 2026. The White Mustard and Metoprolol records this page draws on were last updated July 11, 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 White Mustard

What is White Mustard?

White Mustard
  • Digestive upset
  • Joint and muscle aches (as a topical plaster)
  • Chest congestion
  • Appetite stimulation
  • Mild anti-inflammatory support

White mustard is best known as a culinary seed used to make the mustard condiment, and it has a long history in folk medicine for digestion and as a warming topical plaster. Solid human evidence for its medicinal uses is limited, so it is best enjoyed as a food while keeping medicinal claims in perspective. Talk to your pharmacist or doctor before using concentrated mustard products for health purposes.

Sinapis alba · Brassicaceae · Seeds and leaves · Whole or ground seeds, prepared mustard condiment, powder, poultice/plaster, capsules

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

White Mustard: dosing

There is no established standardized medicinal dose for white mustard. As a food and condiment, it is used in small culinary amounts that are generally considered safe.For any supplement or topical product, follow the directions on the label and do not exceed the recommended amount.

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

Read the full White Mustard monograph & all interactions
Medication

About Metoprolol

What Is Metoprolol Used For?

Brand names: Lopressor, Toprol XL

Metoprolol is used to treat several heart and blood pressure conditions. Metoprolol succinate extended-release tablets (including Toprol-XL) are approved for high blood pressure, angina pectoris (chest pain from the heart), and heart failure. Metoprolol tartrate tablets (including Lopressor) are approved for high blood pressure, angina, and — when used alongside intravenous metoprolol — to reduce the risk of cardiovascular death after a definite or suspected heart attack.

Metoprolol tartrate injection (intravenous form) is used in hemodynamically stable patients with a definite or suspected acute heart attack to reduce cardiovascular death, and is followed by oral metoprolol therapy. Lowering blood pressure with metoprolol reduces the risk of strokes and heart attacks.

Most-Reported Side Effects for Metoprolol

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.

Fatigue 23,416 reports
Dyspnea 20,183 reports
Diarrhea 19,912 reports
Nausea 19,659 reports
Dizziness 16,726 reports
See full Metoprolol drug information
Keep checking

Other Drugs & White Mustard

Browse every other medication we’ve checked against White Mustard — 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 White Mustard 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 White Mustard list.

See the full White Mustard interactions page
See every supplement checked against Metoprolol, ranked by severity
Evidence & sources

White Mustard References

The 3 references that drive our White Mustard 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. Brinker F. Herb Contraindications and Drug Interactions. 2nd ed. Sandy, OR: Eclectic Medical Publications, 1998.
  2. Li J, Jin HZ. Allergic contact dermatitis caused by Chinese herbal medicine, white mustard seed. J Dermatol. 2013;40(1):69-70.
  3. Vereda A, Sirvent S, Villalba M, Rodríguez R, Cuesta-Herranz J, Palomares O. Improvement of mustard (Sinapis alba) allergy diagnosis and management by linking clinical features and component-resolved approaches. J Allergy Clin Immunol. 2011;127(5):1304-7. 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 White Mustard and Metoprolol Together: Common Questions

Is it safe to take White Mustard with Metoprolol?
We do not list a known interaction between White Mustard and Metoprolol. 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 White Mustard and Metoprolol 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.
Should I take White Mustard and Metoprolol at the same time of day?
At least one FDA label for a product containing Metoprolol says to take it with food. If you take White Mustard on an empty stomach out of habit, keep them separate and take Metoprolol with a meal where the label says to. Food instructions belong to the product rather than the ingredient — two Metoprolol products can differ — so check the directions on your own box. This is about absorption, not an interaction.
Does Metoprolol interact with any supplements?
Yes. Metoprolol has documented interactions with 183 supplements in our database — White Mustard is not one of them. The Metoprolol 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

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

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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.