Drug & supplement interaction

Green Tea + Nicardipine

Nicardipine brand names: Cardene, Cardene SR, Cardene IV.

Minor Interaction
Medically reviewed by · Updated October 2026
The bottom line Minor

Nicardipine falls into 2 drug categories that Green Tea can interact with; the most serious is rated minor. Green tea is unlikely to produce clinically significant changes in the levels and clinical effects of CYP3A4 substrates.

Read the full interaction report
SeverityMinor
LikelihoodUnlikely
Interactions2
EvidenceD
What do Severity, Likelihood & Evidence mean?
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Interaction report

Green Tea and Nicardipine

These two interact in 2 distinct ways. Each one is explained separately below.

Why Are There 2 Interactions?

Green Tea interacts with whole categories of medication. Nicardipine falls into 2 of those categories, so it can interact with Green Tea in 2 different ways. We’ve listed each one below — your overall risk is driven by the most serious of them (Minor).

Minor

CYTOCHROME P450 3A4 (CYP3A4) SUBSTRATES

1 of 2

Why this applies to Nicardipine

Nicardipine falls under CYTOCHROME P450 3A4 (CYP3A4) SUBSTRATES — the group Green Tea interacts with.

Green tea is unlikely to produce clinically significant changes in the levels and clinical effects of CYP3A4 substrates.
In vitro and in vivo research suggests that green tea can inhibit intestinal CYP3A and induce hepatic CYP3A4 enzymes. However, this effect is unlikely to be clinically significant, as green tea does not appear to affect CYP3A4 activity in humans.
Severity Minor Likelihood Unlikely Evidence D

Interaction has been demonstrated in animal or in lab research but has been shown not to occur in humans..

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

Here's the good news if you enjoy your daily cup of green tea: when it comes to nicardipine, there's very little to worry about. Nicardipine is handled by an enzyme called CYP3A4, and lab studies hint that green tea might nudge this enzyme in the gut and liver. But in actual humans, green tea doesn't appear to meaningfully change how this enzyme works.

So in theory, if anything shifted nicardipine levels, you could see slightly stronger effects (more flushing, dizziness, or swollen ankles) or slightly weaker blood pressure control. In real life, though, this hasn't been shown to happen. This is based only on test-tube and animal data. Normal tea amounts shouldn't be an issue, but if you're taking concentrated green tea extracts, mention it to your pharmacist or doctor.

Contact Dr. Brian directly if you have additional questions on this interaction
References
  1. Donovan JL, Chavin KD, Devane CL, et al. Green tea (Camellia sinensis) extract does not alter cytochrome P450 3A4 or 2D6 activity in healthy volunteers. Drug Metab Dispos 2004;32:906-8. PubMed
  2. Nishikawa, M., Ariyoshi, N., Kotani, A., Ishii, I., Nakamura, H., Nakasa, H., Ida, M., Nakamura, H., Kimura, N., Kimura, M., Hasegawa, A., Kusu, F., Ohmori, S., Nakazawa, K., and Kitada, M. Effects of continuous ingestion of green tea or grape seed extrac
  3. Chow, H. H., Hakim, I. A., Vining, D. R., Crowell, J. A., Cordova, C. A., Chew, W. M., Xu, M. J., Hsu, C. H., Ranger-Moore, J., and Alberts, D. S. Effects of repeated green tea catechin administration on human cytochrome P450 activity. Cancer Epidemiol.B PubMed
  4. Engdal, S. and Nilsen, O. G. In vitro inhibition of CYP3A4 by herbal remedies frequently used by cancer patients. Phytother.Res. 2009;23(7):906-912.
  5. Schönthal AH. Adverse effects of concentrated green tea extracts. Mol Nutr Food Res. 2011 Jun;55(6):874-85. PubMed
Minor

NICARDIPINE (Cardene)

2 of 2
Theoretically, green tea might increase the levels and adverse effects of nicardipine.
Green tea contains EGCG. Animal research shows that EGCG increases the area under the curve (AUC) and absolute oral bioavailability of nicardipine. The mechanism of action is thought to involve inhibition of both intestinal P-glycoprotein and hepatic cytochrome P450 3A. The effect of green tea itself on nicardipine is unclear.
Severity Minor 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 green tea and your nicardipine. Lab and animal studies suggest a compound in green tea called EGCG can block two things that normally help clear nicardipine: an enzyme (CYP3A) and a gut transporter (P-glycoprotein). When those get slowed down, a bit more nicardipine could reach your bloodstream. In theory, that means slightly stronger effects, like extra dizziness, flushing, headache, swollen ankles, or blood pressure dropping more than expected.

That said, I want to keep this in perspective. This is theoretical and based only on animal data, so what happens in real people is unclear, especially with a regular cup or two of brewed tea. Concentrated green tea extract pills are the bigger question mark. If you're adding those, just give your pharmacist or doctor a heads up so they can keep an eye on your blood pressure.

Contact Dr. Brian directly if you have additional questions on this interaction
References
  1. Choi JS, Burm JP. Effects of oral epigallocatechin gallate on the pharmacokinetics of nicardipine in rats. Arch Pharm Res. 2009 Dec;32(12):1721-5. 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, 908 moderate, 372 minor known drug interactions in our database — the Nicardipine one above is among them. If you take anything else, check it against the full list below.

Major 13 Moderate 908 Minor 372 No known interaction 1,537 (incl. Nicardipine)
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 Nicardipine

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 Nicardipine, 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 Nicardipine

This page covers Green Tea only. If you take other supplements — a multivitamin, a sleep aid, something for joints — the Nicardipine page lists 243 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), Arsenic (major) and Cesium (major).

By severity: 11 major · 191 moderate · 41 minor.

From our pharmacist’s overview on the Nicardipine page

“Nicardipine (Cardene) works by relaxing blood vessels to bring blood pressure down, so a supplement that shifts how much of the drug reaches your blood, or that moves blood pressure on its own, is worth genuine care rather than a shrug. Grapefruit can raise nicardipine levels enough to intensify its effects, while St.”

Reviewed by 2 · Jul 18, 2026

Open the Nicardipine 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 Nicardipine 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 Nicardipine 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%

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

29 days ago today
Medication Nicardipine
Top half

#1,216 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 Nicardipine

What Is Nicardipine Used For?

Brand names: Cardene, Cardene SR, Cardene IV

Nicardipine treats high blood pressure (hypertension). It comes as an oral capsule and as an intravenous (IV) injection given in a medical setting.

Nicardipine capsules are also used to manage chronic stable angina (chest pain brought on by effort). The IV injection products (Cardene I.V. and other nicardipine injections) are for short-term treatment of high blood pressure when oral therapy is not feasible.

See full Nicardipine 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.

13Major
908Moderate
372Minor
1,536No known interaction
13 Major 908 Moderate 372 Minor 1,536 No interaction
Major

13 interactions

Moderate

908 interactions

Showing 60 of 908 moderate interactions — see all 908 on the Green Tea page.

Minor

372 interactions

Showing 60 of 372 minor interactions — see all 372 on the Green Tea page.

No interaction 1,536 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 1,536 medications checked with no known interaction — see the full Green Tea list.

See the full Green Tea interactions page
See every supplement checked against Nicardipine, 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 Nicardipine supplement interactions › Every supplement checked against Nicardipine, ranked by severity Nicardipine 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 Nicardipine Together: Common Questions

Can you take Green Tea with Nicardipine?
There is only a minor interaction, which is usually not serious. Read the full details on this page and confirm with your pharmacist before combining them.
Why are there 2 interactions listed for Green Tea and Nicardipine?
Nicardipine 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 Nicardipine interaction?
We rate it Minor. This interaction is generally not clinically significant, but it remains worth noting and discussing with your pharmacist.

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

Still Have a Question About Nicardipine 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.