Drug & supplement interaction

Ilex Guayusa + Fluvoxamine

Fluvoxamine brand name: Luvox.

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

Ilex Guayusa has a moderate interaction with Fluvoxamine. Theoretically, fluvoxamine might increase the levels and adverse effects of caffeine.

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

Ilex Guayusa and Fluvoxamine

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

Moderate

FLUVOXAMINE (Luvox)

Theoretically, fluvoxamine might increase the levels and adverse effects of caffeine.
Ilex guayusa contains caffeine. Fluvoxamine reduces caffeine metabolism.
Severity Moderate Likelihood Probable Evidence B

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 key thing with this pairing: fluvoxamine slows down the liver enzyme (CYP1A2) that normally clears caffeine out of your body. Since Ilex guayusa is basically a caffeine-rich tea, drinking it while on fluvoxamine means the caffeine can hang around much longer and build up more than you'd expect.

In practice, that can mean a stronger and longer-lasting caffeine effect: jitteriness, a racing or pounding heart, trouble sleeping, anxiety, or an upset stomach. That's a little ironic if you're taking fluvoxamine for anxiety or OCD, since too much caffeine can make those feelings worse. A small cup may be fine for many people, but several servings a day can add up fast. It's worth checking with your pharmacist or doctor about how much is reasonable for you.

Contact Dr. Brian directly if you have additional questions on this interaction
References
  1. Sinclair CJ, Geiger JD. Caffeine use in sports. A pharmacological review. J Sports Med Phys Fitness 2000;40:71-9.
  2. Jeppesen, U., Loft, S., Poulsen, H. E., and Brsen, K. A fluvoxamine-caffeine interaction study. Pharmacogenetics 1996;6(3):213-222. 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

Ilex Guayusa Also Interacts With Other Medications

Ilex Guayusa has 8 major, 469 moderate, 127 minor known drug interactions in our database — the Fluvoxamine one above is one of them. If you take anything else, check it against the full list below.

Major 8 Moderate 469 Minor 127 No known interaction 2,226 (incl. Fluvoxamine)
Taking anything else?

Check Another of Your Medications Against Ilex Guayusa

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

From our Q&A

Questions About Ilex Guayusa or Fluvoxamine

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

This page covers Ilex Guayusa only. If you take other supplements — a multivitamin, a sleep aid, something for joints — the Fluvoxamine page lists 193 supplements it has a documented interaction with, worst first, each one explained.

The most serious there right now: Activated Charcoal (major), Lithium (major), 1,3-dmaa (moderate), 5-htp (moderate) and Acacia Rigidula (moderate).

By severity: 2 major · 151 moderate · 40 minor.

From our pharmacist’s overview on the Fluvoxamine page

“Fluvoxamine (Luvox), an SSRI used for OCD and depression, carries an interaction list that deserves genuinely careful reading. Two entries matter most: lithium, which alongside a serotonin-raising drug like fluvoxamine can tip toward serotonin syndrome, a dangerous excess of serotonin, and activated charcoal, which can soak up the medi…”

Reviewed by 2 · Jul 18, 2026

Open the Fluvoxamine interaction page

How much people look this up

Where Ilex Guayusa and Fluvoxamine 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 Ilex Guayusa
Steady interest

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

29 days ago today
Medication Fluvoxamine
Steady interest

#1,583 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 Ilex Guayusa

What is Ilex Guayusa?

  • Energy and alertness
  • Mental focus
  • Antioxidant support
  • Appetite control
  • Athletic and physical performance

Ilex guayusa is a caffeine-containing holly leaf from the Amazon, traditionally brewed as a tea for energy and alertness, much like yerba mate or green tea. There is limited human research confirming specific health benefits, and its main reliable effect comes from its caffeine content. Because it is a stimulant, use it cautiously and check with your pharmacist or doctor if you have heart concerns or are pregnant.

Read the full Ilex Guayusa monograph & all interactions
Medication

About Fluvoxamine

What Is Fluvoxamine Used For?

Brand name: Luvox

Fluvoxamine is used to treat obsessive compulsive disorder (OCD). OCD involves unwanted, repeated thoughts or images (obsessions) and repeated behaviors (compulsions) that cause distress or get in the way of daily life.

Fluvoxamine maleate tablets treat obsessions and compulsions in people with OCD, including children and adolescents ages 8 to 17. Fluvoxamine maleate extended-release capsules are also indicated for OCD; the capsule's own trial was in adults.

See full Fluvoxamine drug information
Keep checking

Other Drugs & Ilex Guayusa

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

8Major
469Moderate
127Minor
2,225No known interaction
8 Major 469 Moderate 127 Minor 2,225 No interaction
Major

8 interactions

Moderate

469 interactions

Showing 60 of 469 moderate interactions — see all 469 on the Ilex Guayusa page.

Minor

127 interactions

Showing 60 of 127 minor interactions — see all 127 on the Ilex Guayusa page.

No interaction 2,225 drugs checked — show the list

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

Showing the 60 most looked-up of 2,225 medications checked with no known interaction — see the full Ilex Guayusa list.

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

Can you take Ilex Guayusa with Fluvoxamine?
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.
How serious is the Ilex Guayusa and Fluvoxamine 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 Fluvoxamine and Ilex Guayusa?

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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.