Drug & supplement interaction

American Ivy + Letrozole

Letrozole brand name: Femara.

No Known Interaction
Medically reviewed by · Updated June 2026 · Pair last verified Sep 13, 2026
The bottom line No known interaction

We found no known interaction between American Ivy 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

American Ivy 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 American Ivy 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.

American Ivy safety at a glance

American Ivy overall Use caution Little safety data exists, and the berries are toxic, so use it cautiously and avoid eating any part of the plant.
Pregnancy Avoid There is not enough safety information, so it is best to avoid use during pregnancy.
Breastfeeding Avoid Safety while breastfeeding is unknown, so avoiding it is the safer choice.

Safety guidance is general; always confirm with your pharmacist or doctor for your situation.

Still wondering about combining Letrozole and American Ivy? 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. American Ivy has documented interactions with 1 drug class — the most serious being thiazide diuretics (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

American Ivy Does Interact With Other Medications

American Ivy has 56 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 56 No known interaction 2,774 (incl. Letrozole)
Taking anything else?

Check Another of Your Medications Against American Ivy

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

What to actually watch for

What Letrozole’s Own FDA Label Lists

This is not an interaction — none of it involves American Ivy. These are the most notable effects listed in the ADVERSE REACTIONS section of Letrozole’s own FDA label, for the medication by itself. Knowing the drug’s own list makes it easier to work out the likely cause if something new turns up while you take both. One of them is worth acting on rather than waiting out — marked below.

  • Bleeding or bruising Worth acting on
  • Flushing
  • Sweating
  • Joint pain
  • Muscle pain
  • Swelling
  • Tiredness
  • Dizziness
  • Headache
  • Nausea

From the ADVERSE REACTIONS section of the FDA label for Letrozole. Read the label on DailyMed › American Ivy’s licensed record lists no adverse effects our clinical vocabulary could match, so there is no American Ivy side to compare — that is a limit of the record, not a statement that American Ivy has no side effects.

From our Q&A

Questions About American Ivy 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 American Ivy 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 American Ivy 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 American Ivy 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 American Ivy
Steady interest

#1,143 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. American Ivy is not yet covered by that licensed database, so its write-up cites publicly available medical sources directly (see the references below).
  • Citation library: 103,510 references behind our interaction content, 65,311 of them resolved to verified PubMed/DOI sources. See every American Ivy reference on this page ↓
  • Freshness: we automatically re-check this combination every week — this pair was last verified September 13, 2026. The American Ivy and Letrozole records this page draws on were last updated June 22, 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 American Ivy

What is American Ivy?

American Ivy
  • Digestive upset
  • To stimulate sweating
  • Traditional tonic use
  • Skin and swelling complaints (topical folk use)

American Ivy (Virginia creeper) is mainly an ornamental climbing vine with a long history of folk use for digestion and sweating, but there is very little human evidence to support any health benefit. Its berries contain oxalic acid and are considered poisonous, and the plant can irritate the skin. Because safety data is limited, talk with your pharmacist or doctor before using it.

Parthenocissus quinquefolia · Vitaceae · Bark, leaves, and stems (berries are considered poisonous) · Dried bark, tinctures, teas; rarely sold as a standardized supplement

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

American Ivy: dosing

There is no established safe or effective dose for American Ivy. It is not a standardized supplement, so the strength of any product can vary a lot.If you choose to use a product that contains it, follow the directions on the label and do not exceed them. Never make a home preparation from the raw plant or its berries.

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

Read the full American Ivy 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 & American Ivy

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

0Major
56Moderate
0Minor
2,773No known interaction
56 Moderate 2,773 No interaction
Moderate

56 interactions

No interaction 2,773 drugs checked — show the list

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

Showing the 60 most looked-up of 2,773 medications checked with no known interaction — see the full American Ivy list.

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

American Ivy References

The 1 sources that drive our American Ivy monograph — publicly available pages from reputable medical and government organizations. Every link was verified to work before publishing. American Ivy is not covered by the licensed Natural Medicines interaction database, so its page cites these public sources directly.

  1. Oxalates — MedlinePlus Source

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 American Ivy and Letrozole Together: Common Questions

Is it safe to take American Ivy with Letrozole?
We do not list a known interaction between American Ivy 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 American Ivy and Letrozole combination checked?
Interactions in our licensed database are recorded against drug classes. Letrozole is filed under 4 classifications, and American Ivy 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 American Ivy interact with any other medications?
Yes. American Ivy has 56 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 — American Ivy 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

American Ivy 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 1 citations behind this page Ask a pharmacist Free, personal answer from our licensed team

Still Have a Question About Letrozole and American Ivy?

Our pharmacists answer your medication & supplement questions — free.

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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.