Drug & supplement interaction

Caraway + Letrozole

Letrozole brand name: Femara.

No Known Interaction

Medically reviewed by Dr. Brian Staiger, PharmD, BCPS · Updated July 2026 · Pair last verified Sep 13, 2026

The bottom line No known interaction

We found no known interaction between Caraway 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.

Know someone taking this? Share

Facebook Post Reddit Email

On this page

Interaction report

Caraway 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 Caraway 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.

Caraway safety at a glance

Caraway overall Use caution Generally safe in food amounts, but concentrated oil and supplement doses are less studied.

Pregnancy Possibly Unsafe When used in medicinal amounts. Caraway oil has been used to stimulate menstruation; avoid using. Read the full pregnancy detail

Breastfeeding Use caution Food amounts are likely fine, but safety of concentrated supplements while breastfeeding is not well studied.

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 Caraway? 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. Caraway has documented interactions with 7 drug classes — the most serious being antidiabetes drugs (moderate), cns depressants (moderate) and diuretic drugs (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

Caraway Does Interact With Other Medications

Caraway has 408 moderate, 5 minor 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 408 Minor 5 No known interaction 2,417 (incl. Letrozole)

Taking anything else?

Check Another of Your Medications Against Caraway

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

What to actually watch for

No Interaction Found — But Data Suggests Caraway 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.

Nausea Additional detail
Caraway
“Orally, caraway oil, when used in combination with peppermint oil, may cause a substernal burning sensation, belching, nausea, and vomiting. It is unclear if these adverse effects are due to caraway oil, peppermint oil, or the combination. Peppermint oil, when used alone, has been reported to cause similar adverse effects.”

Caraway · Natural Medicines adverse-effect record, reported in nausea and vomiting.
4 sources cited

6741. May B, Kuntz HD, Kieser M, Kohler S. Efficacy of a fixed peppermint oil/caraway oil combination in non-ulcer dyspepsia. Arzneimittelforschung 1996;46:1149-53.

6742. Micklefield GH, Greving I, May B. Effects of peppermint oil and caraway oil on gastroduodenal motility. Phytother Res 2000;14:20-3. DOI

10075. May B, Kohler S, Schneider B. Efficacy and tolerability of a fixed combination of peppermint oil and caraway oil in patients suffering from functional dyspepsia. Aliment Pharmacol Ther 2000;14:1671-7. PubMed

96344. Rich G, Shah A, Koloski N, et al. A randomized placebo-controlled trial on the effects of Menthacarin, a proprietary peppermint- and caraway-oil-preparation, on symptoms and quality of life in patients with functional dyspepsia. Neurogastroenterol Motil 2 PubMed
Letrozole

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

Reported for Caraway but not commonly for Letrozole: an allergic reaction, vomiting, bloating or gas and wheezing.

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

Caraway in Pregnancy & Breastfeeding

Pregnancy Possibly Unsafe

When used in medicinal amounts. Caraway oil has been used to stimulate menstruation; 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 Caraway 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 Caraway 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 Caraway 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

One more smart check

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

We hold 191 real supplement products containing Caraway, each one broken down to its full ingredient list — and combination products often carry several ingredients besides Caraway. Even though Caraway itself has no known interaction with Letrozole, 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 Caraway 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 Caraway

Top half

#400 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 Caraway reference on this page ↓
Freshness: we automatically re-check this combination every week — this pair was last verified September 13, 2026. The Caraway and Letrozole 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 Dr. Brian Staiger, PharmD, BCPS.

Supplement

About Caraway

What is Caraway?

Digestive upset and bloating
Gas (flatulence)
Indigestion (dyspepsia)
Irritable bowel symptoms
Increasing breast milk (traditional)

Caraway is a common cooking spice that has long been used to ease gas, bloating, and indigestion. Some evidence suggests caraway oil—often combined with peppermint oil—may help with indigestion, but evidence for most other uses is limited. Food amounts are generally safe; concentrated oils and supplements should be used cautiously and discussed with your pharmacist or doctor.

Carum carvi · Apiaceae · Seeds (fruit) and essential oil · Whole or ground seeds, tea, capsules, essential oil, tincture

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

Caraway: dosing

There is no official, standardized dose of caraway for any health condition. Doses used in research and products vary widely depending on the form—seeds, tea, oil, or capsules.The best approach is to follow the directions on the product label and not exceed the recommended amount. Essential oil is highly concentrated and should only be used as directed.

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

Read the full Caraway 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 & Caraway

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

0Major

408Moderate

5Minor

2,416No known interaction

408 Moderate 5 Minor 2,416 No interaction

Moderate

408 interactions

Showing 60 of 408 moderate interactions — see all 408 on the Caraway page.

Minor

5 interactions

No interaction 2,416 drugs checked — show the list

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

Showing the 60 most looked-up of 2,416 medications checked with no known interaction — see the full Caraway list.

See the full Caraway interactions page

See every supplement checked against Letrozole, ranked by severity

Evidence & sources

Caraway References

The 11 references that drive our Caraway 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.

Electronic Code of Federal Regulations. Title 21. Part 182 -- Substances Generally Recognized As Safe. Available at: https://www.accessdata.fda.gov/scripts/cdrh/cfdocs/cfcfr/CFRSearch.cfm?CFRPart=182
May B, Kuntz HD, Kieser M, Kohler S. Efficacy of a fixed peppermint oil/caraway oil combination in non-ulcer dyspepsia. Arzneimittelforschung 1996;46:1149-53.
Micklefield GH, Greving I, May B. Effects of peppermint oil and caraway oil on gastroduodenal motility. Phytother Res 2000;14:20-3. DOI
Herb Info Canada. Caraway website. www.herb.plant.org/caraway.htm (Accessed 11 September 2000).
May B, Kohler S, Schneider B. Efficacy and tolerability of a fixed combination of peppermint oil and caraway oil in patients suffering from functional dyspepsia. Aliment Pharmacol Ther 2000;14:1671-7. PubMed
Eddouks M, Lemhardri A, Michel JB. Caraway and caper: potential anti-hyperglycaemic plants in diabetic rats. J Ethnopharmacol 2004;94:143-8. PubMed
Sachin BS, Monica P, Sharma SC, et al. Pharmacokinetic interaction of some antitubercular drugs with caraway: implications in the enhancement of drug bioavailability. Hum Exp Toxicol. 2009;28(4):175-84. PubMed
Lahlou, S., Tahraoui, A., Israili, Z., and Lyoussi, B. Diuretic activity of the aqueous extracts of Carum carvi and Tanacetum vulgare in normal rats. J Ethnopharmacol. 4-4-2007;110(3):458-463. PubMed
de Sousa, D. P., Farias Nobrega, F. F., and de Almeida, R. N. Influence of the chirality of (R)-(-)- and (S)-(+)-carvone in the central nervous system: a comparative study. Chirality 5-5-2007;19(4):264-268.
Modu S, Gohla K Umar IA. The hypoglycaemic and hypocholrsterolaemic properties of black caraway (Carum carvi L.) oil in alloxan diabetic rats. Biokemistri (Nigeria) 1997;7:91-97.
Rich G, Shah A, Koloski N, et al. A randomized placebo-controlled trial on the effects of Menthacarin, a proprietary peppermint- and caraway-oil-preparation, on symptoms and quality of life in patients with functional dyspepsia. Neurogastroenterol Motil 2 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 Caraway and Letrozole Together: Common Questions

Is it safe to take Caraway with Letrozole?

We do not list a known interaction between Caraway 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 Caraway 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 Caraway and Letrozole combination checked?

Interactions in our licensed database are recorded against drug classes. Letrozole is filed under 4 classifications, and Caraway has documented interactions with 7 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 Caraway interact with any other medications?

Yes. Caraway has 413 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 — Caraway 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

Caraway 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 11 citations behind this page Ask a pharmacist Free, personal answer from our licensed team

Still Have a Question About Letrozole and Caraway?

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.