Herb & supplement monograph

Black Mustard Drug Interactions, Uses, Effectiveness, Safety & More

Medically reviewed by Dr. Brian Staiger, PharmD, BCPS ·Updated July 2026

What is this page for?

First and foremost: how Black Mustard interacts with medications. The heart of this page is the interaction list — every drug Black Mustard is known to interact with, and how serious each one is.

But these pages have grown well beyond that into a full monograph — what Black Mustard is, what people use it for and how strong the evidence is, its safety and side effects, and answers to the questions we’re asked most — written and reviewed by the clinical staff at HelloPharmacist. It’s educational information from our licensed clinical databases, not medical advice, and we don’t sell or endorse products. Our editorial policy

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Black Mustard Drug Interactions: The Bottom Line

From the HelloPharmacist Editorial Team · Updated July 2026

Based on the available evidence, the overall risk of a clinically significant Black Mustard drug interaction appears low for most people. None of the listed interactions are rated major, and the concern behind them rests on animal research rather than studies in people.

Interactions deserving the most attention

The interactions that deserve the most attention involve diabetes medications, including insulin and pills that lower blood sugar. Animal studies suggest black mustard seed extracts may lower blood glucose, possibly by affecting insulin release and how the body handles sugar. If that effect happened in people, combining black mustard with these medicines could add up and push blood sugar too low. This has not been confirmed in human studies, so it is a precaution rather than a proven problem.

What the rest of the list means

The long list of interacting medications reflects this single theme: essentially every blood sugar medicine is flagged for the same theoretical reason. A large number of listed interactions does not mean each combination is known to be harmful, and so far the concern comes from lab and animal findings, not from documented cases of harm in people.

Check your medications against Black Mustard

Based on HelloPharmacist’s Black Mustard interaction data and reviewed under our editorial standards.

Interaction report

Drugs that interact with Black Mustard

86 medications have a known interaction with Black Mustard, graded by severity. Select any drug for the full evidence-based detail.

Don’t want to scroll the list? Just ask.

Tell us the medications you take and we’ll check each one against Black Mustard using our pharmacist-reviewed interaction data.

AI summaries are generated from our Black Mustard interaction data for education only — always confirm with your pharmacist. How we use AI

2,830 drugs

Read The List Like a Pharmacist

What Severity, Likelihood & Evidence Mean

Severity — How Serious It Can Be

Major. Clinically significant; generally best avoided, or used only under direct professional supervision.
Moderate. May need monitoring, a dose adjustment, or separating the times you take each one.
Minor. Generally not clinically significant, but still worth noting and mentioning to your pharmacist.
No known interaction. Checked against our sources with nothing documented — not the same as proven safety.

Likelihood — How Well It’s Documented

Likely. Well-controlled human studies have demonstrated the likely existence of this interaction
Probable. Interaction has not been documented in well-controlled studies, however, the interaction has been demonstrated in some small human studies or in controlled animal studies in conjunction with multiple case reports.
Possible. Interaction has been documented in animal or in lab research, or the interaction has been documented in humans but is limited to case reports or conflicting clinical research exists
Unlikely. Interaction has been demonstrated in animal or in lab research but has been shown not to occur in humans.

Where This Data Comes From

Interaction records are evidence-graded and sourced from the Natural Medicines database (TRC Healthcare), the same reference used by pharmacists and hospitals.
Each drug listed above links to the full report for that exact Black Mustard combination — clinical detail, likelihood, evidence level, and citations.
Content is reviewed by licensed HelloPharmacist pharmacists — see our data sources and editorial standards.

The big picture

The kinds of drugs Black Mustard affects

Every type of medication (drug category) Black Mustard is known to interact with. Open any category for the detail — or search your exact drug in the checker above.

All 1 drug category Black Mustard interacts with

Antidiabetes Drugs

Theoretically, black mustard seed might increase the risk of hypoglycemia when used with antidiabetes drugs.
Animal research shows that some extracts of black mustard seeds can reduce blood glucose levels, possibly by regulating the release of insulin and the metabolism of glucose.

Likelihood Possible Evidence D

Monograph

Black Mustard: Uses, Safety & Side Effects

Medically reviewed by Dr. Brian Staiger, PharmD, BCPS · Reviewed July 2026 ·

The bottom line

Black mustard is best known as a pungent culinary spice and a traditional topical remedy for muscle aches and congestion. Solid human evidence for any specific health benefit is limited, and concentrated seed extracts or undiluted oil can irritate or burn the skin. Use it mainly as a food, and talk to a pharmacist or doctor before using it medicinally.

Scientific name: Brassica nigra
Family: Brassicaceae
Part used: Seeds and seed oil; sometimes leaves
Common forms: Whole or ground seeds (spice), mustard oil, poultices/plasters, powder

People commonly use it for

Culinary spice
Muscle and joint aches (topical plaster)
Chest congestion (chest rub or poultice)
Digestive upset
Antioxidant and anti-inflammatory support

Popular and traditional uses — not proof it works. See “Uses & effectiveness” below for the evidence.

Safety at a glance

OverallUse caution

Generally safe as a food spice, but concentrated seeds or oil can irritate the skin and digestive tract.

PregnancyLikely Unsafe

When used orally for medicinal purposes. Black mustard might have abortifacient and menstrual stimulant effects. There is insufficient reliable inform...

Read the full pregnancy detail

BreastfeedingInsufficient reliable information

Insufficient reliable information available; avoid using.

Read the full breastfeeding detail

Pregnancy & breastfeeding ratings are from Natural Medicines (Therapeutic Research Center). Safety guidance is general; always confirm with your pharmacist or doctor for your situation.

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Overview

Black mustard (Brassica nigra) is a flowering plant in the cabbage family. It produces small dark seeds that have a sharp, pungent flavor when crushed and mixed with liquid. The plant grows in many parts of the world, including Europe, Asia, and North America, and is widely cultivated for its seeds.

People use black mustard most often as a spice in cooking and to make condiments like prepared mustard. The seeds and pressed oil also have a long history in traditional medicine, where they were applied to the skin in plasters or poultices to warm sore muscles and ease chest congestion.

How it works

Black mustard seeds contain compounds called glucosinolates. When the seeds are crushed and moistened, an enzyme converts these into allyl isothiocyanate, the substance responsible for mustard's sharp smell and burning sensation.

This compound is what makes mustard feel hot on the skin and the tongue. When applied topically, it irritates and warms the skin and may increase local blood flow, which is the idea behind traditional mustard plasters. Mustard seeds also contain antioxidant plant compounds.

Most of what we know about these mechanisms comes from laboratory and animal research. These studies do not prove that black mustard treats any disease in humans.

Effectiveness

Does Black Mustard work?

Here’s what the research actually shows for each use — graded by Natural Medicines and reviewed by Dr. Brian Staiger, PharmD.

Evidence overview · 3 uses evaluated

3 Insufficient evidence

How to read these evidence grades

Natural Medicines’ 7-point scale. We show each rating’s label word-for-word.

1EffectiveStrong, consistent evidence it works.

2Likely EffectiveGood evidence, though not yet conclusive.

3Possibly EffectiveSome evidence suggests a benefit.

4Possibly IneffectiveSome evidence it may not help.

5Likely IneffectiveFairly strong evidence it doesn’t help.

6IneffectiveStrong evidence it doesn’t work.

7Insufficient Reliable Evidence to RateToo little research to say either way.

For Black Mustard, current evidence isn’t strong enough to rate any specific use. The conditions it has been studied for are listed below.

Also studied for 3 conditions — evidence insufficient to rate

Insufficient Reliable Evidence To Rate Common cold

Rating & evidence shown verbatim from Natural Medicines

Although there is interest in using oral black mustard for the common cold, there is insufficient reliable information about the clinical effects of black mustard for this condition.

Insufficient Reliable Evidence To Rate Osteoarthritis

Rating & evidence shown verbatim from Natural Medicines

Although there is interest in using oral or topical black mustard for osteoarthritis, there is insufficient reliable information about the clinical effects of black mustard for this condition.

Insufficient Reliable Evidence To Rate Pain (acute)

Rating & evidence shown verbatim from Natural Medicines

Although there is interest in using oral or topical black mustard for acute pain, there is insufficient reliable information about the clinical effects of black mustard for this purpose.

Source & disclaimer. Effectiveness ratings and evidence summaries are provided by Natural Medicines (Therapeutic Research Center) and shown as licensed. Where Natural Medicines hasn’t rated a use, HelloPharmacist’s pharmacists may add their own reviewed rating and evidence (each such entry is labeled). This is educational information, not medical advice — talk with your pharmacist or doctor before starting, stopping, or changing a supplement.

Safety & precautions

Used as a spice in normal food amounts, black mustard is generally considered safe for most people. Problems are more likely with concentrated seeds, powders, or oil, especially when applied to the skin.

Mustard plasters and undiluted mustard oil can cause skin irritation, redness, and even chemical burns or blisters if left on too long or used at high strength. People with sensitive skin should be especially careful and test a small area first.

People who are allergic to mustard or other plants in the cabbage family should avoid it. Those with stomach or digestive conditions may find concentrated mustard irritating.

For pregnancy and breastfeeding, eating mustard as a food spice is likely fine, but medicinal or concentrated amounts have not been well studied. Because safety is unclear, it is best to avoid medicinal use during these times and check with a doctor or pharmacist first.

Side effects

When used as a food, side effects are uncommon. Larger or concentrated amounts may cause:

Stomach upset, heartburn, or nausea
Mouth, throat, or stomach irritation from the pungent compounds

When applied to the skin, mustard can cause:

Redness, burning, and stinging
Skin blisters or chemical burns if used too strong or left on too long

Allergic reactions are possible in sensitive people. Seek medical help if you have trouble breathing, swelling, or a severe skin reaction.

Black Mustard: Reported Adverse Effects

Documented safety reports on Black Mustard from the evidence-graded Natural Medicines (TRC Healthcare) database, shown word-for-word from the licensed record.

Reports by condition

Acute respiratory distress syndrome (ARDS) Pulmonary/Respiratory

Orally, taking very large amounts of black mustard seed can lead to breathing difficulties and possibly death. In a case report, a 15 month-old male developed acute, severe respiratory distress after ingesting and aspirating ground black mustard seeds.

Gruenwald J, Brendler T, Jaenicke C. PDR for Herbal Medicines. 1st ed. Montvale, NJ: Medical Economics Company, Inc., 1998.
Gulbransen, G. and Esernio-Jenssen, D. Aspiration of black mustard. J Toxicol.Clin.Toxicol. 1998;36(6):591-593.

Burns Dermatologic

Topically, black mustard oil or powder containing allyl isothiocyanate can cause skin irritation or burns, especially if applied for an extended period of time.

The Review of Natural Products by Facts and Comparisons. St. Louis, MO: Wolters Kluwer Co., 1999.
Leung AY, Foster S. Encyclopedia of Common Natural Ingredients Used in Food, Drugs and Cosmetics. 2nd ed. New York, NY: John Wiley & Sons, 1996.
McGuffin M, Hobbs C, Upton R, Goldberg A, eds. American Herbal Products Association's Botanical Safety Handbook. Boca Raton, FL: CRC Press, LLC 1997.
Gruenwald J, Brendler T, Jaenicke C. PDR for Herbal Medicines. 1st ed. Montvale, NJ: Medical Economics Company, Inc., 1998.

Diarrhea Gastrointestinal

Orally, taking very large amounts of black mustard seed can lead to vomiting, stomach pain, and diarrhea.

Gruenwald J, Brendler T, Jaenicke C. PDR for Herbal Medicines. 1st ed. Montvale, NJ: Medical Economics Company, Inc., 1998.

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.

Adverse-effects data: Natural Medicines, Therapeutic Research Center

Dosing

There is no well-established standardized medicinal dose for black mustard. As a culinary spice, it is simply used to taste in cooking.

For topical or supplement products, follow the directions on the product label, and do not leave mustard plasters on the skin for long periods. If you are considering using black mustard for a health reason, talk with a pharmacist or doctor first to make sure it is appropriate and safe for you.

Pregnancy & Breastfeeding

Black Mustard & Pregnancy

Likely Unsafe

When used orally for medicinal purposes. Black mustard might have abortifacient and menstrual stimulant effects. There is insufficient reliable information available about the safety of black mustard for its other uses during pregnancy; avoid using.

Brinker F. Herb Contraindications and Drug Interactions. 2nd ed. Sandy, OR: Eclectic Medical Publications, 1998.

Black Mustard & Breastfeeding

Insufficient reliable information

Insufficient reliable information available; avoid using.

Pregnancy & lactation ratings: Natural Medicines, Therapeutic Research Center

References & further reading

The 8 references that drive our Black 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.

The Review of Natural Products by Facts and Comparisons. St. Louis, MO: Wolters Kluwer Co., 1999.
Leung AY, Foster S. Encyclopedia of Common Natural Ingredients Used in Food, Drugs and Cosmetics. 2nd ed. New York, NY: John Wiley & Sons, 1996.
McGuffin M, Hobbs C, Upton R, Goldberg A, eds. American Herbal Products Association's Botanical Safety Handbook. Boca Raton, FL: CRC Press, LLC 1997.
Gruenwald J, Brendler T, Jaenicke C. PDR for Herbal Medicines. 1st ed. Montvale, NJ: Medical Economics Company, Inc., 1998.
Brinker F. Herb Contraindications and Drug Interactions. 2nd ed. Sandy, OR: Eclectic Medical Publications, 1998.
Anand, P., Murali, K. Y., Tandon, V., Chandra, R., and Murthy, P. S. Preliminary studies on antihyperglycemic effect of aqueous extract of Brassica nigra (L.) Koch in streptozotocin induced diabetic rats. Indian J Exp.Biol 2007;45(8):696-701.
Anand, P., Murali, Y. K., Tandon, V., Murthy, P. S., and Chandra, R. Insulinotropic effect of aqueous extract of Brassica nigra improves glucose homeostasis in streptozotocin induced diabetic rats. Exp.Clin.Endocrinol.Diabetes 2009;117(6):251-256.
Gulbransen, G. and Esernio-Jenssen, D. Aspiration of black mustard. J Toxicol.Clin.Toxicol. 1998;36(6):591-593. PubMed

Keep reading

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.

Parts of this content are provided by the Therapeutic Research Center, LLC.

DISCLAIMER: Currently this does not check for drug-drug interactions. This is not an all-inclusive comprehensive list of potential interactions and is for informational purposes only. Not all interactions are known or well-reported in the scientific literature, and new interactions are continually being reported. Input is needed from a qualified healthcare provider including a pharmacist before starting any therapy. Application of clinical judgment is necessary.

Brand directory

Brands that make products with Black Mustard

8 brands in our database make a supplement containing Black Mustard.

Banyan Botanicals 697 products Herbal Terra 3,138 products Kirkland Signature 67 products Nature's Plus 903 products Natures Plus 376 products NeoLife Nutritionals 221 products Terry Naturally 523 products Vibrant Health 292 products

Product directory

Supplement products with Black Mustard

77 products in our database contain Black Mustard. Open any to see its full ingredient list and every drug interaction we check.

Pharmacist Counseling Corner

Black Mustard: Common Questions

What is Black Mustard used for, and does it work?

People use Black Mustard for a range of reasons, but according to the Natural Medicines database the current clinical evidence is insufficient to confirm it works for the specific conditions it has been studied for. See the graded list on this page, and talk to your pharmacist or doctor before relying on it for any condition.

Does Black Mustard interact with prescription medications?

Yes. We list 86 medications with a known interaction with Black Mustard. Use the checker above to see how Black Mustard interacts with a specific drug.

How are Black Mustard interactions rated?

Each interaction is graded major, moderate, or minor based on how clinically significant it is and the strength of the evidence behind it. Major interactions are the most serious and are best avoided, or used only under close professional supervision.

Is it safe to take Black Mustard with my medications?

It depends on the specific medication. Some combinations are fine, while others call for monitoring, timing changes, or should be avoided. Check your exact drug above and confirm with your pharmacist or doctor before starting, stopping, or changing anything.

Where does this Black Mustard interaction information come from?

Our interaction data is built on the Natural Medicines database — an evidence-graded reference for vitamins, herbs, and supplements — and is reviewed by licensed HelloPharmacist pharmacists, who may add clinical context.

What is Black Mustard used for?

It is mainly used as a pungent cooking spice. Traditionally, its seeds and oil have also been applied to the skin for sore muscles and chest congestion, though strong human evidence for these uses is lacking.

Is Black Mustard safe?

As a food spice, it is generally safe for most people. Concentrated seeds, powder, or oil can irritate the skin and digestive tract and may cause burns if applied to the skin too strong or too long.

Can I use Black Mustard if I am pregnant or breastfeeding?

Eating it as a normal food spice is likely fine, but medicinal or concentrated amounts have not been studied enough, so it is best to avoid those and ask your doctor or pharmacist.

Why does mustard burn the skin?

When crushed and moistened, mustard seeds release a compound called allyl isothiocyanate, which causes a warming, burning sensation and can irritate or blister the skin if overused.

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

Keep exploring

Products that contain Black Mustard

A rotating sample of real supplements in our database that list Black Mustard — open any to see its full ingredients and every drug interaction we check.

See all 77 products with Black Mustard →

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Black Mustard Drug Interactions, Uses, Effectiveness, Safety & More

Your Choice:

Black Mustard Drug Interactions: The Bottom Line

Drugs that interact with Black Mustard

Don’t want to scroll the list? Just ask.

What Severity, Likelihood & Evidence Mean

Severity — How Serious It Can Be

Likelihood — How Well It’s Documented

Where This Data Comes From

The kinds of drugs Black Mustard affects

Black Mustard: Uses, Safety & Side Effects

Overview

How it works

Does Black Mustard work?

Safety & precautions

Side effects

Black Mustard: Reported Adverse Effects

Dosing

Black Mustard & Pregnancy

Black Mustard & Breastfeeding

References & further reading

Brands that make products with Black Mustard

Supplement products with Black Mustard

Black Mustard: Common Questions

Related supplements & herbs

Products that contain Black Mustard

Have a question about Black Mustard?