Drug & supplement interaction

Green Tea + Armodafinil

Armodafinil brand name: Nuvigil.

Moderate Interaction
The bottom line Moderate

Armodafinil 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 Armodafinil

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. Armodafinil 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 Armodafinil

Armodafinil 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 basic idea: green tea may block a cellular pump called P-glycoprotein (P-gp), which helps move certain drugs out of your body. Armodafinil is considered a possible P-gp substrate, so in theory, slowing that pump could let a little more of it linger in your system. Since armodafinil is active on its own (not a prodrug), more in your blood could mean stronger effects, things like trouble sleeping, headache, jitteriness, a faster heartbeat, or feeling on edge.

I want to keep this in perspective, though. This concern comes from lab studies and a handful of case reports, so it's pretty weak evidence. A cup or two of green tea is unlikely to cause problems for most people. Concentrated green tea extract pills are where I'd be more cautious. If you take both, just check in with your pharmacist or doctor first.

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

STIMULANT DRUGS

2 of 3

Armodafinil also falls under STIMULANT DRUGS.

Theoretically, concomitant use might increase stimulant adverse effects.
Green tea contains caffeine. Due to the central nervous system (CNS) stimulant effects of caffeine, concomitant use with stimulant drugs can increase the risk of adverse effects.
Severity Moderate Likelihood Probable Evidence C

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 simple version: green tea naturally contains caffeine, and caffeine is a stimulant just like Armodafinil (Nuvigil) is. When you stack two stimulants together, their wake-promoting effects can add up. So drinking a lot of strong green tea, or taking concentrated green tea extract, alongside your Armodafinil might leave you feeling extra jittery, with a racing or pounding heartbeat, trouble sleeping, anxiety, or a headache.

This is mostly a theory based on expert opinion rather than hard studies, so please don't panic. A cup or two of green tea is unlikely to cause real trouble for most people. The amount matters most. If you notice the symptoms above, or you use high-dose extracts, check in with your pharmacist or doctor before making any changes.

References
  1. Institute of Medicine. Caffeine for the Sustainment of Mental Task Performance: Formulations for Military Operations. Washington, DC: National Academy Press, 2001. Available at: http://books.nap.edu/books/0309082587/html/index.html. DOI
Minor

CYTOCHROME P450 3A4 (CYP3A4) SUBSTRATES

3 of 3

Armodafinil also falls under CYTOCHROME P450 3A4 (CYP3A4) SUBSTRATES.

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

Good news here: this is a very mild, mostly theoretical concern. Your body relies on an enzyme called CYP3A4 to help break down armodafinil. In lab dishes, green tea can tug on this enzyme in both directions, slowing it in the gut while speeding it up in the liver. The thing is, when researchers looked at real people, green tea didn't meaningfully change how this enzyme actually works.

So drinking green tea with your armodafinil is unlikely to make it stronger or weaker, or to change side effects like headache, jitteriness, or trouble sleeping. The findings come only from test tube and animal studies, not human results. If you take a concentrated green tea extract rather than just sipping the beverage, it's worth a quick check with your pharmacist to be safe.

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

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 Armodafinil one above is among them. If you take anything else, check it against the full list below.

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 Armodafinil

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 Armodafinil, 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 Armodafinil

This page covers Green Tea only. If you take other supplements — a multivitamin, a sleep aid, something for joints — the Armodafinil page lists 223 supplements it has a documented interaction with, worst first, each one explained.

The most serious there right now: Activated Charcoal (major), Ephedra (major), Grapefruit (major), Jalap (major) and Oleander (major).

By severity: 9 major · 176 moderate · 38 minor.

From our pharmacist’s overview on the Armodafinil page

“Armodafinil (Nuvigil) is a wakefulness drug that works like a stimulant, and the supplements that matter most here do the same thing. Nine of the 223 ingredients on file rate major, and this list warrants real care, starting with those nine.”

Reviewed by 2 · Jul 18, 2026

Open the Armodafinil 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 Armodafinil 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 Armodafinil 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%

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

29 days ago today
Medication Armodafinil
Steady interest

#1,727 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 Armodafinil

What Is Armodafinil Used For?

Brand name: Nuvigil

Armodafinil tablets (including the brand Nuvigil) are used to improve wakefulness in adults who have excessive sleepiness linked to one of three conditions: obstructive sleep apnea (OSA), narcolepsy, or shift work disorder (SWD).

In obstructive sleep apnea, armodafinil treats the sleepiness itself — not the underlying airway obstruction. If CPAP (a breathing device worn during sleep) is the right treatment for you, your doctor should try that first before adding armodafinil for sleepiness.

See full Armodafinil 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
904Moderate
375Minor
1,537No known 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
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

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Pharmacist Counseling Corner

Taking Green Tea and Armodafinil Together: Common Questions

Can you take Green Tea with Armodafinil?
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 Armodafinil?
Armodafinil 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 Armodafinil 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 Armodafinil 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.