Drug & supplement interaction

Chicory + 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 Chicory 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.

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Interaction report

Chicory 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 Chicory 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.

Chicory safety at a glance

Chicory overall Use caution Generally well tolerated in food amounts, but may cause gas and can trigger allergies in sensitive people.
Pregnancy Possibly Unsafe When used orally in excessive amounts. Chicory may induce menstruation or miscarriage. Read the full pregnancy detail
Breastfeeding Use caution There is not enough reliable safety information, so it is best to avoid medicinal amounts while breastfeeding.

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 Chicory? 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. Chicory has documented interactions with 1 drug class — the most serious being antidiabetes 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

Chicory Does Interact With Other Medications

Chicory has 86 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 86 No known interaction 2,744 (incl. Letrozole)
Taking anything else?

Check Another of Your Medications Against Chicory

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

What to actually watch for

What Chicory Itself Has Been Linked To

This is not an interaction — nothing below involves Letrozole. It is the side-effect record for Chicory on its own, from the licensed Natural Medicines monograph. If something new turns up after you add Chicory, this list is the first place to look. 3 entries are worth acting on rather than waiting out — marked below.

  • Wheezing Worth acting on Additional detail

    “Occupational exposure to chicory may cause asthma and rhinoconjunctivitis. Dyspnea and anaphylaxis have also been reported in a patient with regular occupational exposure to chicory. This patient also experienced contact dermatitis and generalized pruritus.”

    Chicory · Natural Medicines adverse-effect record, reported in asthma.

    3 sources cited
    1. 41617. Nemery, B. and Demedts, M. Occupational asthma in a chicory grower. Lancet 3-25-1989;1(8639):672-673. PubMed
    2. 93648. Pirson F, Detry B, Pilette C. Occupational rhinoconjunctivitis and asthma caused by chicory and oral allergy syndrome associated with bet v 1-related protein. J Investig Allergol Clin Immunol 2009;19(4):306-10.
    3. 93649. Willi R, Pfab F, Huss-Marp J, et al. Contact anaphylaxis and protein contact dermatitis in a cook handling chicory leaves. Contact Dermatitis 2009;60(4):226-7. PubMed
  • Shortness of breath / A severe allergic reaction Worth acting on Additional detail

    “Occupational exposure to chicory may cause allergic reactions. Dyspnea and anaphylaxis have also been reported in a patient with regular occupational exposure to chicory. This patient also experienced contact dermatitis and generalized pruritus.”

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

    1 source cited
    1. 93649. Willi R, Pfab F, Huss-Marp J, et al. Contact anaphylaxis and protein contact dermatitis in a cook handling chicory leaves. Contact Dermatitis 2009;60(4):226-7. PubMed
  • An allergic reaction Worth acting on Additional detail

    “Occupational exposure to chicory may cause skin rash, contact dermatitis, or generalized pruritus. The sesquiterpene lactones of the plant may be the allergens. Chicory may cause an allergic reaction in individuals sensitive to the Asterceae/Compositae family. Members of this family include ragweed, chrysanthemums, marigolds, daisies, and many other herbs.”

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

    3 sources cited
    1. 41609. Friis, B., Hjorth, N., Vail, J. T., Jr., and Mitchell, J. C. Occupational contact dermatitis from Cichorium (chicory, endive) and Lactuca (lettuce). Contact Dermatitis 1975;1(5):311-313.
    2. 93649. Willi R, Pfab F, Huss-Marp J, et al. Contact anaphylaxis and protein contact dermatitis in a cook handling chicory leaves. Contact Dermatitis 2009;60(4):226-7. PubMed
    3. 25416. Cadot, P., Kochuyt, A. M., van Ree, R., and Ceuppens, J. L. Oral allergy syndrome to chicory associated with birch pollen allergy. Int.Arch.Allergy Immunol. 2003;131(1):19-24. PubMed
  • Bloating or gas Additional detail

    “Orally, fructo-oligosaccharides, such as those extracted from chicory, can cause flatulence, belching, abdominal pains, intestinal sounds and bloating, which occur commonly, but are mild at doses of 10 grams daily.”

    Chicory · Natural Medicines adverse-effect record, reported in flatulence.

    5 sources cited
    1. 740. Stone-Dorshow T, Levitt MD. Gaseous response to ingestion of a poorly absorbed fructo-oligosaccharide sweetener. Am J Clin Nutr 1987;46:61-5. PubMed
    2. 745. Briet F, et al. Symptomatic response to varying levels of fructo-oligosaccharides consumed occasionally or regularly. Eur J Clin Nutr 1995;49:501-7.
    3. 750. Bouhnik Y, Vahedi K, Achour L, et al. Short-chain fructo-oligosaccharide administration dose-dependently increases fecal bifidobacteria in healthy humans. J Nutr 1999;129:113-6. PubMed
    4. 8509. Cummings JH, Macfarlane GT, Englyst HN. Prebiotic digestion and fermentation. Am J Clin Nutr 2001;73:415S-420S. PubMed
    5. 93716. Bonnema AL, Kolberg LW, Thomas W, Slavin JL. Gastrointestinal tolerance of chicory inulin products. J Am Diet Assoc 2010;110(6):865-8. PubMed
  • Itching / A skin rash Additional detail

    Recorded for Chicory in the same Natural Medicines adverse-effect record shown under Wheezing above.

  • Stomach pain Additional detail

    Recorded for Chicory in the same Natural Medicines adverse-effect record shown under Bloating or gas above.

Everything above comes from the Natural Medicines adverse-effect record for Chicory — expand a row for the licensed statement it rests on. We read the ADVERSE REACTIONS section of Letrozole’s FDA label too, and the two lists don’t meaningfully overlap — which is why no Letrozole column appears here.

Special populations

Chicory in Pregnancy & Breastfeeding

Pregnancy Possibly Unsafe

When used orally in excessive amounts. Chicory may induce menstruation or miscarriage.

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

We hold 458 real supplement products containing Chicory, each one broken down to its full ingredient list — and combination products often carry several ingredients besides Chicory. Even though Chicory 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 Chicory 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 Chicory
Top half

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

29 days ago today
Medication Letrozole
Top 5%

#51 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 Chicory reference on this page ↓
  • Freshness: we automatically re-check this combination every week — this pair was last verified September 13, 2026. The Chicory 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 .
Supplement

About Chicory

What is Chicory?

Chicory
  • Constipation and digestive health
  • Source of prebiotic fiber (inulin)
  • Coffee substitute
  • Liver and gallbladder support
  • Appetite and blood sugar (traditional)

Chicory is best known as a caffeine-free coffee substitute and as a source of inulin, a soluble prebiotic fiber that may support digestion and regularity. Strong human evidence for most other traditional uses (like liver, gallbladder, or skin conditions) is limited. It is generally well tolerated, but the inulin can cause gas and bloating, and people allergic to ragweed or related plants should be cautious.

Cichorium intybus · Asteraceae · Root and leaves (the root is the most common medicinal part) · Roasted root (coffee substitute), inulin fiber powder, capsules, tea, liquid extract

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

Chicory: dosing

There is no official standardized dose for chicory. The right amount depends on the form—roasted root for coffee, inulin fiber powder, capsules, or tea—and on the product's concentration.For inulin fiber, it is generally wise to start with a small amount and increase slowly to reduce gas and bloating, and to drink plenty of water.

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

Read the full Chicory 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 & Chicory

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

0Major
86Moderate
0Minor
2,743No known interaction
86 Moderate 2,743 No interaction
Moderate

86 interactions

Showing 60 of 86 moderate interactions — see all 86 on the Chicory page.

No interaction 2,743 drugs checked — show the list

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

Showing the 60 most looked-up of 2,743 medications checked with no known interaction — see the full Chicory list.

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

Chicory References

The 13 references that drive our Chicory 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. Stone-Dorshow T, Levitt MD. Gaseous response to ingestion of a poorly absorbed fructo-oligosaccharide sweetener. Am J Clin Nutr 1987;46:61-5. PubMed
  3. Briet F, et al. Symptomatic response to varying levels of fructo-oligosaccharides consumed occasionally or regularly. Eur J Clin Nutr 1995;49:501-7.
  4. Bouhnik Y, Vahedi K, Achour L, et al. Short-chain fructo-oligosaccharide administration dose-dependently increases fecal bifidobacteria in healthy humans. J Nutr 1999;129:113-6. PubMed
  5. Cummings JH, Macfarlane GT, Englyst HN. Prebiotic digestion and fermentation. Am J Clin Nutr 2001;73:415S-420S. PubMed
  6. Cadot, P., Kochuyt, A. M., van Ree, R., and Ceuppens, J. L. Oral allergy syndrome to chicory associated with birch pollen allergy. Int.Arch.Allergy Immunol. 2003;131(1):19-24. PubMed
  7. Friis, B., Hjorth, N., Vail, J. T., Jr., and Mitchell, J. C. Occupational contact dermatitis from Cichorium (chicory, endive) and Lactuca (lettuce). Contact Dermatitis 1975;1(5):311-313.
  8. Nemery, B. and Demedts, M. Occupational asthma in a chicory grower. Lancet 3-25-1989;1(8639):672-673. PubMed
  9. Pirson F, Detry B, Pilette C. Occupational rhinoconjunctivitis and asthma caused by chicory and oral allergy syndrome associated with bet v 1-related protein. J Investig Allergol Clin Immunol 2009;19(4):306-10.
  10. Willi R, Pfab F, Huss-Marp J, et al. Contact anaphylaxis and protein contact dermatitis in a cook handling chicory leaves. Contact Dermatitis 2009;60(4):226-7. PubMed
  11. Street RA, Sidana J, Prinsloo G. Cichorium intybus: traditional uses, phytochemistry, pharmacology, and toxicology. Evid Based Complement Alternat Med 2013;2013:579319.
  12. Bonnema AL, Kolberg LW, Thomas W, Slavin JL. Gastrointestinal tolerance of chicory inulin products. J Am Diet Assoc 2010;110(6):865-8. PubMed
  13. Devi Kt R, Sivalingam N. Cichorium intybus attenuates Streptozotocin-induced pancreatic ß-cell damage by inhibiting NF-?B activation and oxidative stress. J Appl Biomed 2020;18(2-3):70-9. 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 Chicory and Letrozole Together: Common Questions

Is it safe to take Chicory with Letrozole?
We do not list a known interaction between Chicory 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.
How was the Chicory and Letrozole combination checked?
Interactions in our licensed database are recorded against drug classes. Letrozole is filed under 4 classifications, and Chicory has documented interactions with 1 drug class — 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 Chicory interact with any other medications?
Yes. Chicory has 86 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 — Chicory 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

Chicory 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 13 citations behind this page Ask a pharmacist Free, personal answer from our licensed team

Still Have a Question About Letrozole and Chicory?

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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.