Drug & supplement interaction

Guarana + Fluvoxamine

Fluvoxamine brand name: Luvox.

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

Fluvoxamine falls into 2 drug categories that Guarana can interact with; the most serious is rated moderate. Theoretically, fluvoxamine might increase the levels and adverse effects of caffeine.

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

Guarana and Fluvoxamine

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

Why Are There 2 Interactions?

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

Moderate

FLUVOXAMINE (Luvox)

1 of 2
Theoretically, fluvoxamine might increase the levels and adverse effects of caffeine.
Guarana contains caffeine. Fluvoxamine reduces caffeine metabolism.
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 simple version: guarana is basically a concentrated source of caffeine, and fluvoxamine slows down how your body clears caffeine. Fluvoxamine blocks an enzyme (CYP1A2) that normally breaks caffeine down, so the caffeine from guarana can hang around much longer and build up higher than you'd expect.

In real life that means a regular dose of guarana may hit you like a much bigger one. You could feel jittery, anxious, shaky, or have a racing heart, trouble sleeping, or an upset stomach. That matters even more here, since fluvoxamine is often used for anxiety and OCD, and extra caffeine can work against that calm you're trying to reach. This is based on how the drug works rather than big studies, but it's a sensible caution. Please check with your pharmacist or doctor before combining them.

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.
Minor

CYTOCHROME P450 1A2 (CYP1A2) INHIBITORS

2 of 2

Why this applies to Fluvoxamine

Fluvoxamine falls under CYTOCHROME P450 1A2 (CYP1A2) INHIBITORS — the group Guarana interacts with.

Theoretically, concomitant use might increase the levels and adverse effects of caffeine.
Guarana contains caffeine. Caffeine is metabolized by the CYP1A2 enzyme. Theoretically, drugs that inhibit CYP1A2 may decrease the rate of caffeine clearance and increase caffeine levels.
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 key thing with fluvoxamine (Luvox): it's one of the strongest blockers of an enzyme called CYP1A2, which happens to be the same enzyme your body uses to clear caffeine. Guarana is basically concentrated caffeine. So when you take them together, the caffeine from guarana hangs around longer than usual and can build up.

In plain terms, a normal dose of guarana may hit you harder. You might feel jittery, anxious, have a racing heart, or trouble sleeping. That can be uncomfortable, especially since fluvoxamine itself is often used for anxiety. The evidence here is mostly theoretical, so it's not dangerous for most people, but it's worth knowing. If you enjoy guarana energy drinks or supplements, mention it to your pharmacist or doctor so you can keep your caffeine reasonable.

Contact Dr. Brian directly if you have additional questions on this interaction
References
  1. Hagg S, Spigset O, Mjorndal T, Dahlqvist R. Effect of caffeine on clozapine pharmacokinetics in healthy volunteers. Br J Clin Pharmacol 2000;49:59-63. PubMed
  2. Carrillo JA, Benitez J. Clinically significant pharmacokinetic interactions between dietary caffeine and medications. Clin Pharmacokinet 2000;39:127-53. 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

Guarana Also Interacts With Other Medications

Guarana has 8 major, 461 moderate, 185 minor known drug interactions in our database — the Fluvoxamine one above is among them. If you take anything else, check it against the full list below.

Major 8 Moderate 461 Minor 185 No known interaction 2,176 (incl. Fluvoxamine)
Taking anything else?

Check Another of Your Medications Against Guarana

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

From our Q&A

Questions About Guarana 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 Guarana 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 Guarana 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

One more smart check

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

We hold 1,430 real supplement products containing Guarana, each one broken down to its full ingredient list — and combination products often carry several ingredients besides Guarana. Your product may carry other ingredients that interact with Fluvoxamine too, on top of Guarana — 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 Guarana 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 Guarana
Top 10%

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

29 days ago today
Medication Fluvoxamine
Top 25%

#615 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 Guarana

What is Guarana?

Guarana
  • Energy and alertness
  • Reducing fatigue
  • Weight loss support
  • Athletic performance
  • Mental focus

Guarana is an Amazonian seed that is naturally high in caffeine, which explains most of its stimulant and energy effects. While it may give a short-term boost in alertness and reduce fatigue, strong evidence for weight loss or major performance gains is limited, and it carries the same risks as too much caffeine. Talk to your pharmacist or doctor before using it, especially if you have heart problems, anxiety, or are pregnant.

Read the full Guarana monograph & all interactions
Medication

About Fluvoxamine

What Is Fluvoxamine Used For?

Brand name: Luvox

Both fluvoxamine maleate tablets and Fluvoxamine Maleate extended-release capsules are approved to treat obsessive-compulsive disorder (OCD) — a condition marked by unwanted, recurring thoughts (obsessions) and/or repetitive behaviors (compulsions) that cause significant distress or interfere with daily life.

Fluvoxamine maleate tablets are approved for adults and for children and adolescents ages 8 to 17. Fluvoxamine Maleate extended-release capsules are approved for adults with OCD; their use in pediatric patients naive to fluvoxamine requires special prescriber consideration regarding the lowest available dose.

See full Fluvoxamine drug information
Keep checking

Other Drugs & Guarana

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

8Major
461Moderate
185Minor
2,175No known interaction
8 Major 461 Moderate 185 Minor 2,175 No interaction
Major

8 interactions

Moderate

461 interactions

Showing 60 of 461 moderate interactions — see all 461 on the Guarana page.

Minor

185 interactions

Showing 60 of 185 minor interactions — see all 185 on the Guarana page.

No interaction 2,175 drugs checked — show the list

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

Showing the 60 most looked-up of 2,175 medications checked with no known interaction — see the full Guarana list.

See the full Guarana 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
Guarana 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 Guarana and Fluvoxamine Together: Common Questions

Can you take Guarana 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.
Why are there 2 interactions listed for Guarana and Fluvoxamine?
Fluvoxamine belongs to more than one drug category, and Guarana 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 Guarana 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 Guarana?

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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.