Drug & supplement interaction

Magnolia + 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 Magnolia 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

Magnolia 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 Magnolia 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.

Magnolia safety at a glance

Magnolia overall Use caution May be okay short-term for many adults, but human safety data is limited.
Pregnancy Unsafe When the magnolia flower bud is used orally due to reports of uterine stimulant activity. There is insufficient reliable information available about the safety... Read the full pregnancy detail
Breastfeeding Avoid No reliable safety data during breastfeeding, so it is best avoided.

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 Magnolia? 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. Magnolia has documented interactions with 2 drug classes — the most serious being anticoagulant/antiplatelet drugs (moderate) and cns depressants (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

Magnolia Does Interact With Other Medications

Magnolia has 351 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 351 No known interaction 2,479 (incl. Letrozole)
Taking anything else?

Check Another of Your Medications Against Magnolia

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

What to actually watch for

No Interaction Found — But Data Suggests Magnolia and Letrozole 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.

  • Tiredness / Headache Additional detail

    Magnolia

    “In a clinical trial of an oral combination product containing extracts of magnolia and phellodendron, one patient reported shaking hands and perilabial numbness. Another patient reported fatigue and headache. However, it's not known if these side effects are related to magnolia or some other factor.”

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

    1 source cited
    1. 14349. Garrison R, Chambliss WG. Effect of a proprietary Magnolia and Phellodendron extract on weight management: a pilot, double-blind, placebo-controlled clinical trial. Altern Ther Health Med 2006;12:50-4.

    Letrozole

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

Reported for Magnolia but not commonly for Letrozole: erection problems, a skin rash, heartburn and numbness or tingling.

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

Magnolia in Pregnancy & Breastfeeding

Pregnancy Unsafe

When the magnolia flower bud is used orally due to reports of uterine stimulant activity. There is insufficient reliable information available about the safety of using magnolia bark during pregnancy; 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 Magnolia 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 Magnolia 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 Magnolia 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 Magnolia as Part of a Dietary Supplement Product? Check It for Interactions

We hold 736 real supplement products containing Magnolia, each one broken down to its full ingredient list — and combination products often carry several ingredients besides Magnolia. Even though Magnolia 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 Magnolia 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 Magnolia
Top 25%

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

What is Magnolia?

Magnolia
  • Anxiety and stress
  • Sleep problems
  • Digestive upset
  • Inflammation
  • Nasal congestion and allergies (flower bud)

Magnolia bark and flower buds have a long history in traditional Chinese and Japanese medicine, often for stress, sleep, and digestion. Modern human research is still limited, so we can't be sure how well it works for most uses. Talk with your pharmacist or doctor before trying it, especially if you take other medicines or are pregnant.

Magnolia officinalis · Magnoliaceae · Bark and flower buds · Capsules, tablets, tea, tinctures, and some toothpastes or skin products

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

Magnolia: dosing

There is no well-established standard dose of Magnolia. Products vary widely in how they are prepared and how concentrated they are, and many supplements combine Magnolia with other ingredients.The safest approach is to follow the directions on the product label and not exceed the recommended amount.

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

Read the full Magnolia 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 & Magnolia

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

0Major
351Moderate
0Minor
2,478No known interaction
351 Moderate 2,478 No interaction
Moderate

351 interactions

Showing 60 of 351 moderate interactions — see all 351 on the Magnolia page.

No interaction 2,478 drugs checked — show the list

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

Showing the 60 most looked-up of 2,478 medications checked with no known interaction — see the full Magnolia list.

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

Magnolia References

The 9 references that drive our Magnolia 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. Kuribara H, Kishi E, Hattori N, et al. The anxiolytic effect of two oriental herbal drugs in Japan attributed to honokiol from magnolia bark. J Pharm Pharmacol 2000;52:1425-9. PubMed
  2. Tachikawa E, Takahashi M, Kashimoto T. Effects of extract and ingredients isolated from Magnolia obovata thunberg on catecholamine secretion from bovine adrenal chromaffin cells. Biochem Pharmacol 2000;60:433-40. PubMed
  3. Jung KY, Kim DS, Oh SR, et al. Magnone A and B, novel anti-PAF tetrahydrofuran lignans from the flower buds of Magnolia fargesii. J Nat Prod 1998;61:808-11.
  4. Garrison R, Chambliss WG. Effect of a proprietary Magnolia and Phellodendron extract on weight management: a pilot, double-blind, placebo-controlled clinical trial. Altern Ther Health Med 2006;12:50-4.
  5. Teng CM, Chen CC, Ko FN, et al. Two antiplatelet agents from Magnolia officinalis. Thromb Res 1988;50:757-65. PubMed
  6. Ghys K, De Palma A, Vandevenne A, Werbrouck J, Goossens A. Magnolia officinalis bark extract, a recently identified contact allergen in 'anti-ageing' cosmetics. Contact Dermatitis. 2015 Aug;73(2):130-2.
  7. Raison-Peyron N, Césaire A, Du-Thanh A, Dereure O. Allergic contact dermatitis caused by Magnolia officinalis bark extract in a facial anti-ageing cream. Contact Dermatitis. 2015 Jun;72(6):416-7.
  8. Nilausen TD, Johansen JD, Thyssen JP. Allergic contact dermatitis of the face caused by Magnolia officinalis bark extract. Contact Dermatitis. 2016;75(6):385-87.
  9. Amat-Samaranch V, López-Sánchez C, Tubau C, Puig L, Serra-Baldrich E. Vulvar allergic contact dermatitis caused by Magnolia officinalis bark extract. Contact Dermatitis 2022;87(1):96-97.

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 Magnolia and Letrozole Together: Common Questions

Is it safe to take Magnolia with Letrozole?
We do not list a known interaction between Magnolia 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 Magnolia and Letrozole 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.
How was the Magnolia and Letrozole combination checked?
Interactions in our licensed database are recorded against drug classes. Letrozole is filed under 4 classifications, and Magnolia has documented interactions with 2 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 Magnolia interact with any other medications?
Yes. Magnolia has 351 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 — Magnolia 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

Magnolia 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 9 citations behind this page Ask a pharmacist Free, personal answer from our licensed team

Still Have a Question About Letrozole and Magnolia?

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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.