Drug & supplement interaction

Green Tea + Celiprolol

Celiprolol brand name: Celicard.

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

Celiprolol falls into 3 drug categories that Green Tea can interact with; the most serious is rated moderate. Green tea might increase the levels and adverse effects of P-glycoprotein (P-gp) substrates.

Read the full interaction report
SeverityModerate
LikelihoodPossible
Interactions3
EvidenceD
What do Severity, Likelihood & Evidence mean?
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Interaction report

Green Tea and Celiprolol

These two interact in 3 distinct ways. Each one is explained separately below.

Why Are There 3 Interactions?

Green Tea interacts with whole categories of medication. Celiprolol falls into 3 of those categories, so it can interact with Green Tea in 3 different ways. We’ve listed each one below — your overall risk is driven by the most serious of them (Moderate).

Moderate

P-GLYCOPROTEIN SUBSTRATES

1 of 3

Why this applies to Celiprolol

Celiprolol falls under P-GLYCOPROTEIN SUBSTRATES — the group Green Tea interacts with.

Green tea might increase the levels and adverse effects of P-glycoprotein (P-gp) substrates.
In vitro research and case reports suggest that green tea inhibits drug efflux by P-gp, potentially increasing serum levels of P-gp substrates. Case reports from the World Health Organization (WHO) adverse drug reaction database describe increased toxicity in patients taking green tea and certain P-gp substrates.
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 gist with celiprolol (Celicard): your body relies on a little cellular pump called P-glycoprotein to help move this beta-blocker around and limit how much gets absorbed. Green tea may slow that pump down a bit, which could let a little more celiprolol stay in your system than usual.

If that happens, you might notice the typical beta-blocker effects feel stronger, things like a slower heartbeat, lightheadedness, unusual tiredness, or cold hands and feet. I want to be honest, though: this is based on lab studies and a handful of case reports, so it's only a possible concern, and an occasional cup of tea is unlikely to cause trouble. Concentrated green tea extract pills are the bigger question. Before adding those, check with your pharmacist or doctor.

Contact Dr. Brian directly if you have additional questions on this interaction
References
  1. Pochet S, Lechon AS, Lescrainier C, et al. Herb-anticancer drug interactions in real life based on VigiBase, the WHO global database. Sci Rep 2022;12(1):14178. PubMed
Moderate

ORGANIC ANION-TRANSPORTING POLYPEPTIDE SUBSTRATES (OATP)

2 of 3

Celiprolol also falls under ORGANIC ANION-TRANSPORTING POLYPEPTIDE SUBSTRATES (OATP).

Theoretically, green tea might reduce the absorption of organic anion-transporting polypeptide (OATP) substrates.
OATPs are expressed in the small intestine and liver and are responsible for the uptake of drugs and other compounds. Research shows that two of the major catechins found in green tea, epicatechin gallate (ECG) and epigallocatechin gallate (EGCG), inhibit OATPs, specifically OATP1A2, OATP1B1, and OATP2B1. In addition, green tea has been shown to reduce the absorption of some drugs that are OATP substrates, including lisinopril, and celiprolol.
Severity Moderate Likelihood Probable Evidence D

Interaction 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..

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

Here's the practical takeaway with celiprolol, a beta-blocker often used for blood pressure. Your body relies on special gut transporters called OATPs to soak this drug up from your intestines. Green tea catechins (the antioxidants like EGCG) appear to block those transporters, which means less celiprolol may actually get into your bloodstream. The result could be a weaker effect, so your blood pressure or heart rate might not be controlled as well as expected.

Keep in mind this is mostly based on lab and early studies, though celiprolol is one drug where researchers have actually seen reduced absorption. To play it safe, try not to take your dose at the same time as green tea or green tea extract pills, and check with your pharmacist or doctor before changing anything.

Contact Dr. Brian directly if you have additional questions on this interaction
References
  1. Roth M, Timmermann BN, Hagenbuch B. Interactions of green tea catechins with organic anion-transporting polypeptides. Drug Metab Dispos 2011;39:920-6. PubMed
  2. Abdelkawy KS, Abdelaziz RM, Abdelmageed AM, Donia AM, El-Khodary NM. Effects of green tea extract on atorvastatin pharmacokinetics in healthy volunteers. Eur J Drug Metab Pharmacokinet. 2020;45(3):351-360. PubMed
  3. Kim TE, Ha N, Kim Y, et al. Effect of epigallocatechin-3-gallate, major ingredient of green tea, on the pharmacokinetics of rosuvastatin in healthy volunteers. Drug Des Devel Ther. 2017;11:1409-1416. PubMed
Moderate

CELIPROLOL (Celicard)

3 of 3
Theoretically, green tea might reduce the levels and clinical effects of celiprolol.
In a small human study, taking green tea daily for 4 days appears to decrease blood and urine levels of celiprolol by at least 98%. This interaction is possibly due to the inhibition of organic anion transporting polypeptide (OATP). Green tea catechins have been shown to inhibit organic anion transporting polypeptides (OATP), one of which, OATP1A2, is found in the intestine The interaction is thought to be due primarily to the epigallocatechin gallate (EGCG) content of green tea.
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 something worth knowing if you take celiprolol (Celicard) for blood pressure. Your gut uses a little transporter called OATP1A2 to absorb this beta-blocker. Green tea, especially its catechin EGCG, can block that transporter, so less of the drug actually gets into your bloodstream. In one small human study, drinking green tea for several days dropped celiprolol levels by almost all of it (around 98%).

What that means in plain terms: your celiprolol may simply not work as well, so your blood pressure could creep back up. This isn't about your medicine being dangerous, it's about it possibly doing too little. The evidence is limited and mostly anecdotal, but the drop seen was big. Easy fix is timing and consistency, so please ask your pharmacist or doctor before changing anything.

Contact Dr. Brian directly if you have additional questions on this interaction
References
  1. Roth M, Timmermann BN, Hagenbuch B. Interactions of green tea catechins with organic anion-transporting polypeptides. Drug Metab Dispos 2011;39:920-6. PubMed
  2. 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
  3. 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
  4. Sonoda J, Ogata K, Yoshikawa N, Sato K, Ikeda R, Shimodozono Y. Impact of green tea intake on the pharmacokinetics of celiprolol in healthy subjects. Int J Clin Pharmacol Ther. 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 13 major, 904 moderate, 375 minor known drug interactions in our database — the Celiprolol one above is among them. If you take anything else, check it against the full list below.

Major 13 Moderate 904 Minor 375 No known interaction 1,538 (incl. Celiprolol)
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 Celiprolol

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 Celiprolol, 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 Celiprolol

This page covers Green Tea only. If you take other supplements — a multivitamin, a sleep aid, something for joints — the Celiprolol page lists 170 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), Apple (major) and Grapefruit (major).

By severity: 9 major · 135 moderate · 26 minor.

From our pharmacist’s overview on the Celiprolol page

“Someone taking celiprolol (Celicard) for high blood pressure may be the same person pouring apple juice at breakfast, and that ordinary habit is where this list bites. Nine of its 170 ingredients rate major, and those deserve your attention first.”

Reviewed by 2 · Jul 18, 2026

Open the Celiprolol 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 Celiprolol 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 Celiprolol 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 Celiprolol
Top half

#1,123 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
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.

13Major
904Moderate
375Minor
1,537No known interaction
13 Major 904 Moderate 375 Minor 1,537 No interaction
Major

13 interactions

Moderate

904 interactions

Showing 60 of 904 moderate interactions — see all 904 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 Celiprolol, 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 Celiprolol supplement interactions › Every supplement checked against Celiprolol, 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 Ask a pharmacist › Free, personal answer from our licensed team
Pharmacist Counseling Corner

Taking Green Tea and Celiprolol Together: Common Questions

Can you take Green Tea with Celiprolol?
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.
Why are there 3 interactions listed for Green Tea and Celiprolol?
Celiprolol belongs to more than one drug category, and Green Tea interacts with each of those categories a little differently. We list every one so nothing is missed — your overall risk is driven by the most serious of them.
How serious is the Green Tea and Celiprolol 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 Celiprolol 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.