Drug & supplement interaction

Green Tea + Nadolol

Nadolol brand names: Corgard, Nadolol.

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

Green Tea has a major interaction with Nadolol. Green tea seems to reduce the levels and clinical effects of nadolol.

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

Green Tea and Nadolol

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

Major

NADOLOL (Corgard)

Green tea seems to reduce the levels and clinical effects of nadolol.
Preliminary clinical research shows that green tea consumption reduces plasma concentrations of nadolol. Compared to a control group, both peak levels and total drug exposure (AUC) of nadolol were reduced by approximately 85% in subjects who drank green tea daily for two weeks. Drinking green tea with nadolol also significantly reduced nadolol's systolic blood pressure lowering effect. Other clinical research shows that a single dose of green tea can affect plasma nadolol levels for at least one hour. Green tea catechins have been shown to inhibit organic anion transporting polypeptides (OATP), one of which, OATP1A2, is involved in the uptake of nadolol in the intestine The interaction is thought to be due primarily to the epigallocatechin gallate (EGCG) content of green tea.
Severity Major Likelihood Likely Evidence B

Well-controlled human studies have demonstrated the likely existence of this interaction.

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

Here's something a lot of people don't expect: drinking green tea can actually weaken how well nadolol works. The catechins in green tea (especially one called EGCG) block a gut transporter that your body uses to absorb nadolol. When that transporter is slowed down, less of the medicine gets into your bloodstream. In one study, green tea cut nadolol levels by about 85 percent, and people's blood pressure wasn't controlled as well.

So this isn't a case of nadolol building up. It's the opposite, you may get less benefit, meaning your blood pressure or chest pain could be less controlled than you'd think. This is a fairly well-documented effect, not just a theory. Please don't stop your green tea or your medicine on your own. Talk with your pharmacist or doctor about timing or whether to limit green tea while on nadolol.

Contact Dr. Brian directly if you have additional questions on this interaction
References
  1. Misaka S, Yatabe J, Muller F, et al. Green Tea Ingestion Greatly Reduces Plasma Concentrations of Nadolol in Healthy Subjects. Clin Pharmacol Ther 2014. [Epub ahead of print]. PubMed
  2. Roth M, Timmermann BN, Hagenbuch B. Interactions of green tea catechins with organic anion-transporting polypeptides. Drug Metab Dispos 2011;39:920-6. PubMed
  3. Kato Y, Miyazaki T, Kano T, et al. Involvement of influx and efflux transport systems in gastrointestinal absorption of celiprolol. J Pharm Sci 2009;98:2529-39. PubMed
  4. Abe O, Ono T, Sato H, et al. Role of (-)-epigallocatechin gallate in the pharmacokinetic interaction between nadolol and green tea in healthy volunteers. Eur J Clin Pharmacol 2018;74(6):775-83. doi: 10.1007/s00228-018-2436-2. PubMed
  5. Misaka S, Abe O, Ono T, et al. Effects of single green tea ingestion on pharmacokinetics of nadolol in healthy volunteers. Br J Clin Pharmacol. 2020. 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

Green Tea Also Interacts With Other Medications

Green Tea has 12 major, 905 moderate, 375 minor known drug interactions in our database — the Nadolol one above is one of them. If you take anything else, check it against the full list below.

Major 12 Moderate 905 Minor 375 No known interaction 1,538 (incl. Nadolol)
Taking anything else?

Check Another of Your Medications Against Green Tea

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

From our Q&A

Questions About Green Tea or Nadolol

These are real questions from readers, answered by the pharmacists at HelloPharmacist — written by a person, not generated from a database. Each one covers Green Tea or Nadolol, 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 Nadolol

This page covers Green Tea only. If you take other supplements — a multivitamin, a sleep aid, something for joints — the Nadolol page lists 145 supplements it has a documented interaction with, worst first, each one explained.

The most serious there right now: Activated Charcoal (major), American Hellebore (major), American Mistletoe (major), Indian Snakeroot (major) and Tyramine (major).

By severity: 6 major · 119 moderate · 20 minor.

From our pharmacist’s overview on the Nadolol page

“If you take nadolol (Corgard) for blood pressure, angina, or heart rhythm, treat this list with real care, and green tea is the surprise at the top. In a clinical study, green tea cut nadolol blood levels by roughly 85 percent, which can quietly leave you undertreated.”

Reviewed by 2 · Jul 18, 2026

Open the Nadolol interaction page

One more smart check

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

We hold 9,084 real supplement products containing Green Tea, each one broken down to its full ingredient list — and combination products often carry several ingredients besides Green Tea. Your product may carry other ingredients that interact with Nadolol too, on top of Green Tea — 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 Green Tea and Nadolol 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 Green Tea
Top 5%

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

29 days ago today
Medication Nadolol
Steady interest

#1,419 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 Green Tea

What is Green Tea?

Green Tea
  • Antioxidant support
  • Weight loss
  • Heart health
  • Mental alertness
  • Cancer risk reduction

Green tea is a popular beverage rich in antioxidants called catechins, and drinking it in normal amounts is considered safe for most people. Concentrated green tea extracts are a different story—they may help modestly with weight or heart health for some, but high doses have been linked to rare liver problems. Talk to your pharmacist or doctor before taking green tea supplements, especially if you have liver concerns or are pregnant.

Read the full Green Tea monograph & all interactions
Medication

About Nadolol

What Is Nadolol Used For?

Brand names: Corgard, Nadolol

Nadolol tablets are used for two main conditions: high blood pressure (hypertension) and angina pectoris (ongoing chest pain caused by reduced blood flow to the heart). Lowering high blood pressure reduces the risk of stroke and heart attack.

For high blood pressure, nadolol may be prescribed on its own or combined with other blood pressure medications, especially thiazide-type diuretics (water pills). For angina, it is used for long-term management to help reduce how often chest pain occurs.

See full Nadolol drug information
Keep checking

Other Drugs & Green Tea

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

12Major
905Moderate
375Minor
1,537No known interaction
12 Major 905 Moderate 375 Minor 1,537 No interaction
Major

12 interactions

Moderate

905 interactions

Showing 60 of 905 moderate interactions — see all 905 on the Green Tea page.

Minor

375 interactions

Showing 60 of 375 minor interactions — see all 375 on the Green Tea page.

No interaction 1,537 drugs checked — show the list

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

Showing the 60 most looked-up of 1,537 medications checked with no known interaction — see the full Green Tea list.

See the full Green Tea interactions page
See every supplement checked against Nadolol, 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
Green Tea monograph › Uses, safety, and every drug interaction in one place Nadolol supplement interactions › Every supplement checked against Nadolol, ranked by severity Nadolol 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 Green Tea and Nadolol Together: Common Questions

Can you take Green Tea with Nadolol?
This is rated a major interaction, so the combination is best avoided unless your doctor or pharmacist has specifically told you otherwise. Read the full details on this page and confirm with your pharmacist before combining them.
How serious is the Green Tea and Nadolol interaction?
We rate it Major. This is a clinically significant combination that is generally best avoided, or used only under the direct supervision of your physician or pharmacist.

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

Still Have a Question About Nadolol and Green Tea?

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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.