Drug & supplement interaction

Theaflavin + Baloxavir Marboxil

Baloxavir Marboxil brand name: Xofluzanda.

No Known Interaction
The bottom line No known interaction

We found no known interaction between Theaflavin and Baloxavir Marboxil 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

Theaflavin and Baloxavir Marboxil

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 Baloxavir Marboxil and Theaflavin 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.

Theaflavin safety at a glance

Theaflavin overall Use caution Black tea is generally safe in normal amounts, but concentrated extracts are less studied.
Pregnancy Use caution Limit caffeine-containing tea and avoid high-dose extracts unless your doctor approves.
Breastfeeding Use caution Caffeine passes into breast milk, so limit intake and avoid concentrated extracts.

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

Still wondering about combining Baloxavir Marboxil and Theaflavin? Ask Dr. Brian Staiger, PharmD, BCPS directly ›
How we checked

Why No Interaction Is Listed for Baloxavir Marboxil

Interactions in our licensed database are recorded against drug classes, not just single drug names. Baloxavir Marboxil is filed under a single classification — oral drugs. Theaflavin has documented interactions with 2 drug classes — the most serious being antidiabetes drugs (moderate) and organic anion-transporting polypeptide substrates (oatp) (moderate) — and none of Baloxavir Marboxil’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

Theaflavin Does Interact With Other Medications

Theaflavin has 130 moderate known drug interactions in our database — Baloxavir Marboxil isn’t one of them. If you take anything else, check it against the full list below.

Taking anything else?

Check Another of Your Medications Against Theaflavin

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

What to actually watch for

What Baloxavir Marboxil’s Own FDA Label Lists

This is not an interaction — none of it involves Theaflavin. These are the most notable effects listed in the ADVERSE REACTIONS section of Baloxavir Marboxil’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.

  • Diarrhea
  • Vomiting
  • Headache
  • Nausea

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

Everything else you take

See Every Supplement That Interacts With Baloxavir Marboxil

This page covers Theaflavin only. If you take other supplements — a multivitamin, a sleep aid, something for joints — the Baloxavir Marboxil page lists 17 supplements it has a documented interaction with, worst first, each one explained.

The most serious there right now: Activated Charcoal (major), Coffee Charcoal (moderate), European Mandrake (moderate), Glucomannan (moderate) and Guar Gum (moderate).

By severity: 1 major · 7 moderate · 9 minor.

From our pharmacist’s overview on the Baloxavir Marboxil page

“Activated charcoal is the supplement I would keep farthest from baloxavir marboxil (Xofluzanda), the single-dose flu antiviral, and it carries the only major rating among the 17 ingredients on file here. Charcoal adsorbs drugs in the gut, and because this whole flu treatment is one dose, a blunted dose has no follow-up pill to rescue it.”

Reviewed by 2 · Jul 18, 2026

Open the Baloxavir Marboxil interaction page

One more smart check

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

We hold 11 real supplement products containing Theaflavin, each one broken down to its full ingredient list — and combination products often carry several ingredients besides Theaflavin. Even though Theaflavin itself has no known interaction with Baloxavir Marboxil, 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 Theaflavin and Baloxavir Marboxil 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 Theaflavin
Top half

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

29 days ago today
Medication Baloxavir Marboxil
Steady interest

#1,736 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 Theaflavin reference on this page ↓
  • Freshness: we automatically re-check this combination every week — this pair was last verified September 13, 2026. The Theaflavin and Baloxavir Marboxil 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 Theaflavin

What is Theaflavin?

  • Heart health and cholesterol support
  • Antioxidant support
  • Weight management
  • Blood sugar support
  • General wellness

Theaflavins are antioxidant compounds formed when tea leaves are oxidized to make black tea. Early research suggests they may help with cholesterol and provide antioxidant effects, but high-quality human evidence is limited and doses are not standardized. Drinking black tea is generally safe, but talk to your pharmacist or doctor before taking concentrated extracts.

Camellia sinensis · Theaceae · Leaves (fermented/oxidized, as in black tea) · Black tea, standardized black tea extract capsules, tablets, powders

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

Theaflavin: dosing

There is no established standard dose of theaflavin. Supplements vary widely in how much theaflavin they contain and how the black tea extract is standardized.If you choose to take a product, follow the directions on the label and do not exceed the recommended amount. Drinking black tea is a simpler, well-tolerated way to get theaflavins for most people.

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

Read the full Theaflavin monograph & all interactions
Medication

About Baloxavir Marboxil

What Is Baloxavir Marboxil Used For?

Brand name: Xofluzanda

Xofluza is used to treat acute uncomplicated influenza (flu) in people 5 years of age and older who have had symptoms for no more than 48 hours — whether they are otherwise healthy or at high risk of developing flu-related complications.

Xofluza is also used for post-exposure prophylaxis (preventing flu after exposure) in people 5 years and older who have been in close contact with someone who has influenza.

Most-Reported Side Effects for Baloxavir Marboxil

From FAERS, the FDA’s public side-effect reporting system (0 reports, all brands). Reports are voluntary and are not proof the drug caused the effect.

Diarrhea 136 reports
Vomiting 132 reports
Pneumonia 114 reports
Nausea 75 reports
Rash 68 reports
See full Baloxavir Marboxil drug information
Keep checking

Other Drugs & Theaflavin

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

0Major
130Moderate
0Minor
2,699No known interaction
Moderate

130 interactions

Showing 60 of 130 moderate interactions — see all 130 on the Theaflavin page.

No interaction 2,699 drugs checked — show the list
Evidence & sources

Theaflavin References

The 4 references that drive our Theaflavin 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. Maron DJ, Lu GP, Cai NS, et al. Cholesterol-lowering effect of a theaflavin-enriched green tea extract: a randomized controlled trial. Arch Intern Med 2003;163:1448-53.. PubMed
  2. Takemoto M, Takemoto H, Kouno H, Soeda T, Moriya T. A simple, enzymatic biotransformation method using fresh green tea leaves efficiently generates theaflavin-containing fermentation water that has potent physiological functions in mice and humans. Biol P PubMed
  3. Kondo A, Narumi K, Okuhara K, et al. Black tea extract and theaflavin derivatives affect the pharmacokinetics of rosuvastatin by modulating organic anion transporting polypeptide (OATP) 2B1 activity. Biopharm Drug Dispos. 2019;40(8):302-306. PubMed
  4. Gothandam K, Ganesan VS, Ayyasamy T, Ramalingam S. Antioxidant potential of theaflavin ameliorates the activities of key enzymes of glucose metabolism in high fat diet and streptozotocin - induced diabetic rats. Redox Rep. 2019;24(1):41-50. 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 Theaflavin and Baloxavir Marboxil Together: Common Questions

Is it safe to take Theaflavin with Baloxavir Marboxil?
We do not list a known interaction between Theaflavin and Baloxavir Marboxil. 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 Theaflavin and Baloxavir Marboxil combination checked?
Interactions in our licensed database are recorded against drug classes. Baloxavir Marboxil is filed under 1 classification, and Theaflavin has documented interactions with 2 drug classes — none of Baloxavir Marboxil'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 Theaflavin interact with any other medications?
Yes. Theaflavin has 130 documented drug interactions in our database — Baloxavir Marboxil 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 Baloxavir Marboxil interact with any supplements?
Yes. Baloxavir Marboxil has documented interactions with 17 supplements in our database — Theaflavin is not one of them. The Baloxavir Marboxil interaction page linked on this page lists every one, ranked by severity.

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

Still Have a Question About Baloxavir Marboxil and Theaflavin?

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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.