Drug & supplement interaction

Beet + Thiotepa

Thiotepa brand names: Thioplex, Tepadina.

Moderate Interaction
Medically reviewed by · Updated September 2026
The bottom line Moderate

Beet has a moderate interaction with Thiotepa. Theoretically, beet might increase the levels of CYP3A4 substrates.

Read the full interaction report
SeverityModerate
LikelihoodPossible
EvidenceD
What do Severity, Likelihood & Evidence mean?
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Interaction report

Beet and Thiotepa

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

Moderate

CYTOCHROME P450 3A4 (CYP3A4) SUBSTRATES

Why this applies to Thiotepa

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

Theoretically, beet might increase the levels of CYP3A4 substrates.
In vitro research suggests that betanin, the major pigment in beet, competitively inhibits CYP3A4 in a dose-dependent manner similarly to strong CYP3A4 inhibitor ketoconazole.
Severity Moderate Likelihood Possible Evidence D

Interaction 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.

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

Here's the situation with beet and thiotepa. Thiotepa is a chemotherapy drug that your liver partly processes using an enzyme called CYP3A4. Lab studies hint that betanin (the red pigment in beets) can slow that same enzyme down, similar to how a strong blocker would. If that happened in real life, thiotepa could build up and its effects might feel stronger, which for a chemo drug can mean worse side effects like low blood counts, nausea, mouth sores, or more fatigue.

Now the honest part: this is only based on test-tube research, not studies in people, so we really don't know how much it matters. Eating a normal serving of beets is very different from taking concentrated beet supplements. Please don't change anything on your own. Loop in your oncology team or pharmacist first.

Contact Dr. Brian directly if you have additional questions on this interaction
References
  1. Lim SH, Bae S, Lee HS, Han HK, Choi CI. Effect of Betanin, the Major Pigment of Red Beetroot (Beta vulgaris L.), on the Activity of Recombinant Human Cytochrome P450 Enzymes. Pharmaceuticals (Basel) 2023;16(9):1224. 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

Beet Also Interacts With Other Medications

Beet has 642 moderate, 218 minor known drug interactions in our database — the Thiotepa one above is one of them. If you take anything else, check it against the full list below.

Moderate 642 Minor 218 No known interaction 1,970 (incl. Thiotepa)
Taking anything else?

Check Another of Your Medications Against Beet

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

Everything else you take

See Every Supplement That Interacts With Thiotepa

This page covers Beet only. If you take other supplements — a multivitamin, a sleep aid, something for joints — the Thiotepa page lists 146 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), Acacia Rigidula (moderate) and Acerola (moderate).

By severity: 3 major · 102 moderate · 41 minor.

From our pharmacist’s overview on the Thiotepa page

“Thiotepa (Thioplex, Tepadina) is chemotherapy, given for several cancers and to prepare patients for stem cell transplant, so its 146 supplement interactions make up a list to respect rather than skim. Three carry a major rating: grapefruit, St.”

Reviewed by 2 · Jul 18, 2026

Open the Thiotepa interaction page

One more smart check

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

We hold 4,785 real supplement products containing Beet, each one broken down to its full ingredient list — and combination products often carry several ingredients besides Beet. Your product may carry other ingredients that interact with Thiotepa too, on top of Beet — 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 Beet and Thiotepa 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 Beet
Top 5%

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

29 days ago today
Medication Thiotepa
Top 25%

#516 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 Beet

What is Beet?

Beet
  • High blood pressure
  • Exercise and athletic performance
  • Heart and circulation support
  • General antioxidant/anti-inflammatory support
  • Liver and digestive support

Beet, especially beetroot juice, is a nitrate-rich food that may modestly lower blood pressure and slightly improve exercise performance in some people. It is generally safe as a food, but supplement effects are modest and not a substitute for prescribed treatment, so talk with your pharmacist or doctor before relying on it.

Read the full Beet monograph & all interactions
Medication

About Thiotepa Injection

What Is Thiotepa Injection Used For?

Brand names: Thioplex, Tepadina

Tepadina (thiotepa) injection is used for several purposes. It treats adenocarcinoma (a type of cancer) of the breast or ovary. It is also used to control malignant effusions — abnormal fluid buildup in body cavities caused by cancer spreading to those areas. For bladder cancer, Tepadina treats superficial papillary carcinoma of the urinary bladder.

Tepadina is also used in pediatric patients with class 3 beta-thalassemia (a severe inherited blood disorder). In those patients, it is given as part of a preparative regimen — a conditioning treatment to reduce the risk of graft rejection before an allogeneic stem cell transplant (a transplant using donor stem cells), alongside the chemotherapy drugs busulfan and cyclophosphamide.

See full Thiotepa Injection drug information
Keep checking

Other Drugs & Beet

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

0Major
642Moderate
218Minor
1,969No known interaction
642 Moderate 218 Minor 1,969 No interaction
Moderate

642 interactions

Showing 60 of 642 moderate interactions — see all 642 on the Beet page.

Minor

218 interactions

Showing 60 of 218 minor interactions — see all 218 on the Beet page.

No interaction 1,969 drugs checked — show the list

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

Showing the 60 most looked-up of 1,969 medications checked with no known interaction — see the full Beet list.

See the full Beet interactions page
See every supplement checked against Thiotepa, ranked by severity
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

Keep exploring
Beet monograph › Uses, safety, and every drug interaction in one place Thiotepa supplement interactions › Every supplement checked against Thiotepa, ranked by severity Thiotepa Injection drug information › The full plain-English guide to this medication Supplement interaction checker › Check any supplement or product against your medications Browse medications A–Z › Every drug we've checked against herbs & supplements Ask a pharmacist › Free, personal answer from our licensed team
Pharmacist Counseling Corner

Taking Beet and Thiotepa Together: Common Questions

Can you take Beet with Thiotepa?
There is a moderate interaction, so it may be acceptable with monitoring or timing changes — but check with your pharmacist first. Read the full details on this page and confirm with your pharmacist before combining them.
How serious is the Beet and Thiotepa interaction?
We rate it Moderate. This combination may require monitoring, a dose adjustment, or separating the times you take each one. Consult your pharmacist before using them together.

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

Still Have a Question About Thiotepa and Beet?

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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.