Drug & supplement interaction

Oolong Tea + Gemifloxacin

Gemifloxacin brand name: Factive.

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

Oolong Tea has a minor interaction with Gemifloxacin. Theoretically, quinolone antibiotics might increase the levels and adverse effects of caffeine in oolong tea.

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

Oolong Tea and Gemifloxacin

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

Minor

QUINOLONE ANTIBIOTICS

Why this applies to Gemifloxacin

Gemifloxacin falls under QUINOLONE ANTIBIOTICS — the group Oolong Tea interacts with.

Theoretically, quinolone antibiotics might increase the levels and adverse effects of caffeine in oolong tea.
Oolong tea contains caffeine. Quinolones decrease caffeine clearance.
Severity Minor Likelihood Possible Evidence B

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 simple version: this interaction isn't really about the gemifloxacin (Factive) itself, it's about the caffeine in your oolong tea. Fluoroquinolone antibiotics like gemifloxacin can slow down how fast your body clears caffeine. With it leaving your system more slowly, the caffeine can hang around longer and feel a little stronger than usual.

In practice that might mean more jitteriness, a faster heartbeat, trouble sleeping, or feeling wired, especially if you drink several cups a day. The good news is this is rated a minor interaction, and gemifloxacin is one of the weaker fluoroquinolones for this effect, so an occasional cup is unlikely to cause trouble. If you notice the buzz, just cut back. Check with your pharmacist if you're sensitive to caffeine.

Contact Dr. Brian directly if you have additional questions on this interaction
References
  1. Harder S, Fuhr U, Staib AH, Wolff T. Ciprofloxacin-caffeine: a drug interaction established using in vivo and in vitro investigations. Am J Med 1989;87:89S-91S. PubMed
  2. Carbo M, Segura J, De la Torre R, et al. Effect of quinolones on caffeine disposition. Clin Pharmacol Ther 1989;45:234-40. PubMed
  3. Healy DP, Polk RE, Kanawati L, et al. Interaction between oral ciprofloxacin and caffeine in normal volunteers. Antimicrob Agents Chemother 1989;33:474-8. 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

Oolong Tea Also Interacts With Other Medications

Oolong Tea has 8 major, 518 moderate, 125 minor known drug interactions in our database — the Gemifloxacin one above is one of them. If you take anything else, check it against the full list below.

Major 8 Moderate 518 Minor 125 No known interaction 2,179 (incl. Gemifloxacin)
Taking anything else?

Check Another of Your Medications Against Oolong Tea

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

Everything else you take

See Every Supplement That Interacts With Gemifloxacin

This page covers Oolong Tea only. If you take other supplements — a multivitamin, a sleep aid, something for joints — the Gemifloxacin page lists 81 supplements it has a documented interaction with, worst first, each one explained.

The most serious there right now: Activated Charcoal (major), Apple (major), Grapefruit (major), Sweet Orange (major) and Bacillus Coagulans (moderate).

By severity: 4 major · 56 moderate · 21 minor.

From our pharmacist’s overview on the Gemifloxacin page

“Picture a week on gemifloxacin (Factive) for pneumonia or a stubborn bronchitis: juice with breakfast, a probiotic, maybe calcium. That ordinary morning is where the trouble sits, and this list warrants real care.”

Reviewed by 2 · Jul 18, 2026

Open the Gemifloxacin interaction page

One more smart check

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

We hold 75 real supplement products containing Oolong Tea, each one broken down to its full ingredient list — and combination products often carry several ingredients besides Oolong Tea. Your product may carry other ingredients that interact with Gemifloxacin too, on top of Oolong 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 Oolong Tea and Gemifloxacin 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 Oolong Tea
Steady interest

#1,110 of 1,452 supplements looked up here in the last 7 days

29 days ago today
Medication Gemifloxacin
Top half

#1,326 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 Oolong Tea

What is Oolong Tea?

  • Weight management
  • Mental alertness and energy
  • Heart health
  • Blood sugar support
  • Antioxidant support

Oolong tea is a traditional partially oxidized tea made from the same plant as green and black tea, and it provides caffeine and plant antioxidants. As a beverage it is generally considered safe for most healthy adults in moderate amounts, but evidence for specific health benefits like weight loss or blood sugar control is limited. If you have heart, blood pressure, or caffeine-sensitivity concerns, talk with your pharmacist or doctor.

Read the full Oolong Tea monograph & all interactions
Medication

About Gemifloxacin

What Is Gemifloxacin Used For?

Brand name: Factive

  • Gemifloxacin is used to treat pneumonia. Gemifloxacin may also be used to treat bronchitis but should not be used for this condition if there are other treatment options. Gemifloxacin is in a class of antibiotics called fluoroquinolones. It works by killing bacteria that cause infections.

  • Antibiotics such as gemifloxacin do not work for colds, flu, or other viral infections. Using antibiotics when they are not needed increases your risk of getting an infection later that resists antibiotic treatment.

See full Gemifloxacin drug information
Keep checking

Other Drugs & Oolong Tea

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

8Major
518Moderate
125Minor
2,178No known interaction
8 Major 518 Moderate 125 Minor 2,178 No interaction
Major

8 interactions

Moderate

518 interactions

Showing 60 of 518 moderate interactions — see all 518 on the Oolong Tea page.

Minor

125 interactions

Showing 60 of 125 minor interactions — see all 125 on the Oolong Tea page.

No interaction 2,178 drugs checked — show the list

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

Showing the 60 most looked-up of 2,178 medications checked with no known interaction — see the full Oolong Tea list.

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

Can you take Oolong Tea with Gemifloxacin?
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.
How serious is the Oolong Tea and Gemifloxacin 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 Gemifloxacin and Oolong 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.