Drug & supplement interaction

Theaflavin + 6-Mercaptopurine

6-Mercaptopurine brand name: Purinethol.

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 Theaflavin and 6-Mercaptopurine 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 6-Mercaptopurine

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 6-Mercaptopurine 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 6-Mercaptopurine and Theaflavin? Ask Dr. Brian Staiger, PharmD, BCPS directly ›
How we checked

Why No Interaction Is Listed for 6-Mercaptopurine

Interactions in our licensed database are recorded against drug classes, not just single drug names. 6-Mercaptopurine is filed under 3 classifications — immunosuppressants, hepatotoxic drugs, 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 6-Mercaptopurine’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 — 6-Mercaptopurine isn’t one of them. If you take anything else, check it against the full list below.

Moderate 130 No known interaction 2,700 (incl. 6-Mercaptopurine)
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 6-Mercaptopurine’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 6-Mercaptopurine’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. 9 of them are worth acting on rather than waiting out — marked below.

  • Low blood sugar Worth acting on
  • A low white blood cell count Worth acting on mentioned in 11.0% of FDA reports for 6-Mercaptopurine
  • Pancreatitis Worth acting on
  • A low platelet count Worth acting on
  • Anemia Worth acting on
  • Raised blood pressure Worth acting on
  • Hives Worth acting on
  • Liver problems Worth acting on
  • A higher chance of infection Worth acting on
  • Fever mentioned in 17.9% of FDA reports for 6-Mercaptopurine

Showing the 10 most notable of 18 label-listed effects — ranked by how unusual each one is across medicines generally, with serious effects weighted up.

From the ADVERSE REACTIONS section of the FDA label for 6-Mercaptopurine. Read the label on DailyMed › Where a percentage is shown, it is the share of 17,242 voluntary FDA FAERS reports for 6-Mercaptopurine that mention that effect — a reporting proportion, not an incidence rate and not evidence the drug caused it. 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.

From our Q&A

Questions About Theaflavin or 6-Mercaptopurine

These are real questions from readers, answered by the pharmacists at HelloPharmacist — written by a person, not generated from a database. Each one covers Theaflavin or 6-Mercaptopurine, 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 6-Mercaptopurine

This page covers Theaflavin only. If you take other supplements — a multivitamin, a sleep aid, something for joints — the 6-Mercaptopurine page lists 106 supplements it has a documented interaction with, worst first, each one explained.

The most serious there right now: Activated Charcoal (major), Beer (major), Siberian Cocklebur (major), Wine (major) and Active Hexose Correlated Compound (ahcc) (moderate).

By severity: 4 major · 92 moderate · 10 minor.

From our pharmacist’s overview on the 6-Mercaptopurine page

“6-Mercaptopurine (Purinethol) works by dialing down your immune system, whether for leukemia or inflammatory bowel disease, and that makes this a list to check with real care. The four major-rated entries come first.”

Reviewed by 2 · Jul 18, 2026

Open the 6-Mercaptopurine 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 6-Mercaptopurine, 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 6-Mercaptopurine 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

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

29 days ago today
Medication 6-Mercaptopurine
Steady interest

#1,654 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 6-Mercaptopurine 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 Mercaptopurine

What Is Mercaptopurine Used For?

Brand name: Purinethol

Mercaptopurine — available as a tablet and as an oral suspension — is used to treat acute lymphoblastic leukemia (ALL), a type of blood cancer. It is given as part of a combination chemotherapy maintenance regimen, meaning it works alongside other cancer medicines to keep leukemia in remission.

Both the tablet form and the oral suspension form carry this indication for adult and pediatric patients. The oral suspension is particularly useful for patients who cannot swallow tablets.

See full Mercaptopurine 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
130 Moderate 2,699 No 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

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

Showing the 60 most looked-up of 2,699 medications checked with no known interaction — see the full Theaflavin list.

See the full Theaflavin interactions page
See every supplement checked against 6-Mercaptopurine, ranked by severity
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 6-Mercaptopurine Together: Common Questions

Is it safe to take Theaflavin with 6-Mercaptopurine?
We do not list a known interaction between Theaflavin and 6-Mercaptopurine. 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 6-Mercaptopurine combination checked?
Interactions in our licensed database are recorded against drug classes. 6-Mercaptopurine is filed under 3 classifications, and Theaflavin has documented interactions with 2 drug classes — none of 6-Mercaptopurine'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 — 6-Mercaptopurine 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 6-Mercaptopurine interact with any supplements?
Yes. 6-Mercaptopurine has documented interactions with 106 supplements in our database — Theaflavin is not one of them. The 6-Mercaptopurine 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

Theaflavin monograph Uses, safety profile, and every drug interaction in one place Mercaptopurine drug information The full plain-English guide to this medication 6-Mercaptopurine supplement interactions Every supplement checked against 6-Mercaptopurine, 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 4 citations behind this page Ask a pharmacist Free, personal answer from our licensed team

Still Have a Question About 6-Mercaptopurine 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.