Drug & supplement interaction

Pomegranate + Letrozole

Letrozole brand name: Femara.

Minor Interaction
The bottom line Minor

Pomegranate has a minor interaction with Letrozole. Theoretically, pomegranate might increase levels of drugs metabolized by CYP3A4, but most research suggests this interaction is unlikely to be clinically significant.

Read the full interaction report
SeverityMinor
LikelihoodUnlikely
EvidenceB
What do Severity, Likelihood & Evidence mean?
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Interaction report

Pomegranate and Letrozole

Here is the interaction we found between these two, with the evidence behind it.

Minor

CYTOCHROME P450 3A4 (CYP3A4) SUBSTRATES

Why this applies to Letrozole

Letrozole falls under CYTOCHROME P450 3A4 (CYP3A4) SUBSTRATES — the group Pomegranate interacts with.

Theoretically, pomegranate might increase levels of drugs metabolized by CYP3A4, but most research suggests this interaction is unlikely to be clinically significant.
Pomegranate contains several polyphenols that have individually been shown to inhibit CYP3A4. However, there is contradictory evidence about the effect of whole pomegranate juice on CYP3A4 activity. In vitro, pomegranate juice significantly inhibits the CYP3A4 enzyme, with comparable inhibition to grapefruit juice. In an animal model, pomegranate juice inhibits CYP3A4 metabolism of carbamazepine and increases levels of carbamazepine by 1.5 times; however, in human volunteers, drinking a single glass of pomegranate juice 240 mL or taking 200 mL daily for 2 weeks does not significantly affect levels of the CYP3A4 substrate midazolam after oral or intravenous administration. Another study in healthy volunteers shows that consuming pomegranate juice 300 mL three times daily for three days also does not significantly affect levels of simvastatin, a CYP3A4 substrate This suggests that pomegranate is unlikely to significantly affect levels of CYP3A4 substrates in humans.
Severity Minor Likelihood Unlikely Evidence B

Interaction has been demonstrated in animal or in lab research but has been shown not to occur in humans..

Dr. Brian Staiger, PharmD, BCPS
Dr. Brian Staiger explains PharmD, Clinical Pharmacist

Here's the gist for letrozole (Femara): your body clears it largely through a liver enzyme called CYP3A4. Pomegranate has plant compounds that, in a test tube, can slow that same enzyme. In theory, slowing it could let letrozole build up a little, which might mean more of its usual effects like joint aches, hot flashes, tiredness, or stiffness.

The reassuring part is that this is mostly theoretical. When researchers actually gave people pomegranate juice with real CYP3A4 medications, drug levels didn't meaningfully change. So enjoying pomegranate as a food or normal glass of juice is very unlikely to cause trouble. Concentrated extracts are less studied, so check with your pharmacist or doctor before using those, and never adjust your letrozole on your own.

References
  1. Hidaka M, Okumura M, Fujita K, et al. Effects of pomegranate juice on human cytochrome p450 3A (CYP3A) and carbamazepine pharmacokinetics in rats. Drug Metab Dispos 2005;33:644-8. PubMed
  2. Farkas D, Oleson LE, Zhao Y, et al. Pomegranate juice does not impair clearance of oral or intravenous midazolam, a probe for cytochrome P450-3A activity: comparison with grapefruit juice. J Clin Pharmacol 2007;47:286-94. PubMed
  3. Yeo C, Shon J, Liu K, et al. The effects of pomegranate juice on the pharmacokinetics of simvastatin in healthy Korean subjects (PI-63). Clin Pharmacol Ther 2006;79:23.
  4. Farkas D, Greenblatt DJ. Influence of fruit juices on drug disposition: discrepancies between in vitro and clinical studies. Expert Opin Drug Metab Toxicol 2008;4:381-93.
  5. Misaka S, Nakamura R, Uchida S, et al. Effect of 2 weeks' consumption of pomegranate juice on the pharmacokinetics of a single dose of midazolam: an open-label, randomized, single-center, 2-period crossover study in healthy Japanese volunteers. Clin Ther PubMed
  6. Park SJ, Yeo CW, Shim EJ, et al. Pomegranate juice does not affect the disposition of simvastatin in healthy subjects. Eur J Drug Metab Pharmacokinet 2016;41(4):339-44. PubMed

What These Ratings Mean

Every interaction above is graded three ways — here’s the key to each label.

Severity how clinically significant the interaction is
Major

Clinically significant. Avoid the combination, or use only under close professional supervision.

Moderate

Usually worth avoiding or managing — may need monitoring, a dose change, or timing apart.

Minor

Generally not serious. Be aware of it and mention it to your pharmacist.

Likelihood how strong the evidence is that the interaction actually happens in people
  • LikelyWell-controlled human studies have demonstrated the likely existence of this interaction.
  • ProbableInteraction has not been documented in well-controlled studies, however, the interaction has been demonstrated in some small human studies or in controlled animal studies in conjunction with multiple case reports.
  • PossibleInteraction has been documented in animal or in lab research, or the interaction has been documented in humans but is limited to case reports or conflicting clinical research exists.
  • UnlikelyInteraction has been demonstrated in animal or in lab research but has been shown not to occur in humans.
Evidence the quality of the studies behind the rating (graded A–D)
  • AHigh-quality meta-analysis (quantitative systematic review).
  • BCase-control study.
  • CConsensus.
  • DAnecdotal evidence.

These ratings are for information only. Never start, stop, or otherwise change your therapy before speaking with your provider.

Keep it in perspective

Pomegranate Also Interacts With Other Medications

Pomegranate has 355 moderate, 566 minor known drug interactions in our database — the Letrozole one above is one of them. If you take anything else, check it against the full list below.

Taking anything else?

Check Another of Your Medications Against Pomegranate

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

From our Q&A

Questions About Pomegranate 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 Pomegranate 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 Pomegranate 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 Pomegranate as Part of a Dietary Supplement Product? Check It for Interactions

We hold 4,607 real supplement products containing Pomegranate, each one broken down to its full ingredient list — and combination products often carry several ingredients besides Pomegranate. Your product may carry other ingredients that interact with Letrozole too, on top of Pomegranate — and those would not show on this page. Find your product and we’ll check every ingredient on its label:

How much people look this up

Where Pomegranate 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 Pomegranate
Top 5%

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

29 days ago today
Medication Letrozole
Top 5%

#49 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.

Supplement

About Pomegranate

What is Pomegranate?

Pomegranate
  • Heart and blood vessel health
  • Antioxidant support
  • High blood pressure
  • Inflammation
  • Digestive upset
  • Skin health

Pomegranate is a nutrient-rich fruit that is high in antioxidants and is widely enjoyed as food and juice. Early research suggests it may support heart health and blood pressure, but the evidence is still limited and not strong enough to call it a proven treatment. As a food it is generally safe, but talk to your pharmacist or doctor before using concentrated extracts, especially if you are pregnant, breastfeeding, or take medications.

Read the full Pomegranate 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 & Pomegranate

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

0Major
355Moderate
566Minor
1,908No known interaction
Moderate

355 interactions

Showing 60 of 355 moderate interactions — see all 355 on the Pomegranate page.

Minor

566 interactions

Showing 60 of 566 minor interactions — see all 566 on the Pomegranate page.

No interaction 1,908 drugs checked — show the list
Sources

Sources & How We Checked

Interaction details are evidence-graded and sourced from the Natural Medicines database. The medication overview comes from MedlinePlus.

Content is written and reviewed by licensed HelloPharmacist pharmacists. See our data sources and editorial standards for how this information is built and checked.

Parts of this content are provided by the Therapeutic Research Center, LLC.

DISCLAIMER: Currently this does not check for drug-drug interactions. This is not an all-inclusive comprehensive list of potential interactions and is for informational purposes only. Not all interactions are known or well-reported in the scientific literature, and new interactions are continually being reported. Input is needed from a qualified healthcare provider including a pharmacist before starting any therapy. Application of clinical judgment is necessary.

© 2021 Therapeutic Research Center, LLC

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Pharmacist Counseling Corner

Taking Pomegranate and Letrozole Together: Common Questions

Can you take Pomegranate with Letrozole?
There is only a minor interaction, which is usually not serious. Read the full details on this page and confirm with your pharmacist before combining them.
How serious is the Pomegranate and Letrozole interaction?
We rate it Minor. This interaction is generally not clinically significant, but it remains worth noting and discussing with your pharmacist.

Written and reviewed by the HelloPharmacist editorial staff. Our editorial policy

Still Have a Question About Letrozole and Pomegranate?

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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.