Drug & supplement interaction

Hedge Mustard + Letrozole

Letrozole brand name: Femara.

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 Hedge Mustard and Letrozole 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

Hedge Mustard and Letrozole

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 Letrozole and Hedge 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.

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.

Hedge Mustard safety at a glance

Hedge Mustard overall Use caution Generally considered low-risk for short-term use in adults, but human safety data are limited.
Pregnancy Possibly Unsafe When used orally; avoid using. Read the full pregnancy detail
Breastfeeding Possibly Unsafe When used orally; 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 Letrozole and Hedge Mustard? Ask Dr. Brian Staiger, PharmD, BCPS directly ›
How we checked

Why No Interaction Is Listed for Letrozole

Interactions in our licensed database are recorded against drug classes, not just single drug names. Letrozole is filed under 4 classifications — including aromatase inhibitors, cytochrome p450 2c19 (cyp2c19) inhibitors, cytochrome p450 3a4 (cyp3a4) substrates. Hedge Mustard has documented interactions with 6 drug classes — the most serious being digoxin (lanoxin) (moderate), diuretic drugs (moderate) and macrolide antibiotics (moderate) — and none of Letrozole’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

Hedge Mustard Does Interact With Other Medications

Hedge Mustard has 133 moderate known drug interactions in our database — Letrozole isn’t one of them. If you take anything else, check it against the full list below.

Moderate 133 No known interaction 2,697 (incl. Letrozole)
Taking anything else?

Check Another of Your Medications Against Hedge Mustard

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

What to actually watch for

No Interaction Found — But Data Suggests Hedge Mustard and Letrozole May Share a Side Effect

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.

  • Headache Additional detail

    Hedge Mustard

    “Orally, hedge mustard might be unsafe due to its cardiac glycoside constituents. Topically, no adverse effects have been reported. However, a thorough evaluation of safety outcomes has not been conducted for either route of administration.

    Serious Adverse Effects (Rare):

    Orally: Theoretically, digitalis-like effects including cardiac rhythm disorders, diarrhea, headache, and vomiting.”

    Hedge Mustard · Natural Medicines adverse-effect record, reported in cluster headache.

    “Orally, hedge mustard may theoretically cause digitalis-like effects such as headache (18).”

    Hedge Mustard · Natural Medicines adverse-effect record, reported in cluster headache.

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

    Letrozole

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

Reported for Hedge Mustard but not commonly for Letrozole: vomiting and diarrhea.

Effects for Letrozole come from the ADVERSE REACTIONS section of its FDA label; effects for Hedge 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

Hedge Mustard in Pregnancy & Breastfeeding

Pregnancy And Lactation Possibly Unsafe

When used orally; 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

From our Q&A

Questions About Hedge Mustard or Letrozole

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

This page covers Hedge Mustard only. If you take other supplements — a multivitamin, a sleep aid, something for joints — the Letrozole page lists 142 supplements it has a documented interaction with, worst first, each one explained.

The most serious there right now: Activated Charcoal (major), Grapefruit (major), St. John's Wort (major), 7-methoxyflavone (moderate) and Acacia Rigidula (moderate).

By severity: 3 major · 99 moderate · 40 minor.

From our pharmacist’s overview on the Letrozole page

“Letrozole (Femara) is prescribed to keep hormone-driven breast cancer from returning, so a supplement that shifts its blood level can quietly undercut treatment. Give this list of 142 ingredients genuine respect, and learn the three major entries first.”

Reviewed by 2 · Jul 18, 2026

Open the Letrozole interaction page

How much people look this up

Where Hedge Mustard and Letrozole 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 Hedge Mustard
Steady interest

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

29 days ago today
Medication Letrozole
Top 5%

#50 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 Hedge Mustard reference on this page ↓
  • Freshness: we automatically re-check this combination every week — this pair was last verified September 13, 2026. The Hedge Mustard and Letrozole 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 Hedge Mustard

What is Hedge Mustard?

  • Hoarseness and voice loss
  • Sore throat
  • Cough
  • Mild laryngitis
  • Throat irritation

Hedge mustard is a traditional European herb long nicknamed the 'singer's plant' because it was used to soothe hoarseness and sore throats. Solid scientific evidence for these uses is very limited, so it is best seen as a folk remedy rather than a proven treatment. Talk to your pharmacist or doctor before using it, and avoid it during pregnancy and breastfeeding.

Sisymbrium officinale · Brassicaceae · Aerial parts (leaves, stems, flowers) and seeds · Tea, syrup, tincture, lozenges, gargle/throat preparations

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

Hedge Mustard: dosing

There is no well-established standardized dose for hedge mustard. Traditional use involves teas, syrups, and tinctures made from the aerial parts of the plant, but amounts vary widely between products and recipes.If you choose to use a commercial product, follow the directions on the label and do not exceed the recommended amount.

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

Read the full Hedge Mustard monograph & all interactions
Medication

About Letrozole

What Is Letrozole Used For?

Brand name: Femara

Letrozole (brand name Femara) is used to treat breast cancer in postmenopausal women whose tumors are driven by estrogen. It is used in three settings: as adjuvant (after-surgery) treatment for hormone receptor positive early breast cancer; as extended adjuvant treatment for women who have already completed about five years of tamoxifen therapy; and as first- or second-line treatment for locally advanced or metastatic (spread) breast cancer.

Femara is specifically indicated for first-line treatment of hormone receptor positive or receptor-unknown locally advanced or metastatic breast cancer, and for advanced breast cancer in women whose disease has progressed after antiestrogen therapy.

See full Letrozole drug information
Keep checking

Other Drugs & Hedge Mustard

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

0Major
133Moderate
0Minor
2,696No known interaction
133 Moderate 2,696 No interaction
Moderate

133 interactions

Showing 60 of 133 moderate interactions — see all 133 on the Hedge Mustard page.

No interaction 2,696 drugs checked — show the list

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

Showing the 60 most looked-up of 2,696 medications checked with no known interaction — see the full Hedge Mustard list.

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

Hedge Mustard References

The 4 references that drive our Hedge 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. Blumenthal M, ed. The Complete German Commission E Monographs: Therapeutic Guide to Herbal Medicines. Trans. S. Klein. Boston, MA: American Botanical Council, 1998.
  2. Ellenhorn MJ, et al. Ellenhorn's Medical Toxicology: Diagnoses and Treatment of Human Poisoning. 2nd ed. Baltimore, MD: Williams & Wilkins, 1997.
  3. Gruenwald J, Brendler T, Jaenicke C. PDR for Herbal Medicines. 1st ed. Montvale, NJ: Medical Economics Company, Inc., 1998.
  4. Burnham TH, ed. Drug Facts and Comparisons, Updated Monthly. Facts and Comparisons, St. Louis, MO.

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 Hedge Mustard and Letrozole Together: Common Questions

Is it safe to take Hedge Mustard with Letrozole?
We do not list a known interaction between Hedge Mustard and Letrozole. 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 Hedge Mustard and Letrozole have any of the same side effects?
Yes — our sources link each of them separately to one 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.
How was the Hedge Mustard and Letrozole combination checked?
Interactions in our licensed database are recorded against drug classes. Letrozole is filed under 4 classifications, and Hedge Mustard has documented interactions with 6 drug classes — none of Letrozole'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 Hedge Mustard interact with any other medications?
Yes. Hedge Mustard has 133 documented drug interactions in our database — Letrozole 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 Letrozole interact with any supplements?
Yes. Letrozole has documented interactions with 142 supplements in our database — Hedge Mustard is not one of them. The Letrozole 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

Hedge Mustard monograph Uses, safety profile, and every drug interaction in one place Letrozole drug information The full plain-English guide to this medication Letrozole supplement interactions Every supplement checked against Letrozole, 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 4 citations behind this page Ask a pharmacist Free, personal answer from our licensed team

Still Have a Question About Letrozole and Hedge 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.