Drug & supplement interaction

Zedoary + Caffeine (OTC drug)

Caffeine (OTC drug) brand names: Vivarin, Overtime, Molie.

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

Zedoary has a moderate interaction with Caffeine (OTC drug). Theoretically, zedoary might increase levels of drugs metabolized by CYP3A4.

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

Zedoary and Caffeine (OTC drug)

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

Moderate

CYTOCHROME P450 3A4 (CYP3A4) SUBSTRATES

Why this applies to Caffeine (OTC drug)

Caffeine (OTC drug) falls under CYTOCHROME P450 3A4 (CYP3A4) SUBSTRATES — the group Zedoary interacts with.

Theoretically, zedoary might increase levels of drugs metabolized by CYP3A4.
In-vitro research shows that a methanol extract of zedoary strongly inhibits the CYP3A4 metabolism of the tyrosine kinase inhibitors lapatinib and sorafenib, and to a lesser extent, gefitinib.
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 gist with zedoary and a caffeine pill like Vivarin. The concern on file is that zedoary may slow down a liver enzyme called CYP3A4, which can let certain drugs build up. Caffeine is not a prodrug, so if anything got blocked, you'd expect a bit more caffeine effect, not less, meaning more jitteriness, a racing heart, trouble sleeping, or an upset stomach.

That said, this is purely theoretical. It comes from test tube studies, and caffeine is actually cleared mostly by a different enzyme (CYP1A2), not 3A4. So in real life this combo is unlikely to cause much trouble. Still, if you notice you feel extra wired, mention it to your pharmacist or doctor.

Contact Dr. Brian directly if you have additional questions on this interaction
References
  1. Rodseeda C, Yamanont P, Pinthong D, Korprasertthaworn P. Inhibitory effects of Thai herbal extracts on the cytochrome P450 3A-mediated the metabolism of gefitinib, lapatinib and sorafenib. Toxicol Rep 2022;9:1846-1852. 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

Zedoary Also Interacts With Other Medications

Zedoary has 642 moderate known drug interactions in our database — the Caffeine (OTC drug) one above is one of them. If you take anything else, check it against the full list below.

Moderate 642 No known interaction 2,188 (incl. Caffeine (OTC drug))
Taking anything else?

Check Another of Your Medications Against Zedoary

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

Everything else you take

See Every Supplement That Interacts With Caffeine (OTC drug)

This page covers Zedoary only. If you take other supplements — a multivitamin, a sleep aid, something for joints — the Caffeine (OTC drug) page lists 208 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), Peyote (major) and Rauvolfia Vomitoria (major).

By severity: 7 major · 155 moderate · 46 minor.

From our pharmacist’s overview on the Caffeine (OTC drug) page

“The person swallowing a caffeine pill like Vivarin to power through a shift is often the same person drinking coffee, taking an herbal energy blend, or scooping pre-workout powder, and that overlap is exactly where the danger sits. Seven of the 208 supplement ingredients on file carry a major rating, and those seven are worth understan…”

Reviewed by 2 · Jul 18, 2026

Open the Caffeine (OTC drug) interaction page

One more smart check

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

We hold 83 real supplement products containing Zedoary, each one broken down to its full ingredient list — and combination products often carry several ingredients besides Zedoary. Your product may carry other ingredients that interact with Caffeine (OTC drug) too, on top of Zedoary — 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 Zedoary and Caffeine (OTC drug) 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 Zedoary
Steady interest

#1,022 of 1,452 supplements looked up here in the last 7 days

29 days ago today
Medication Caffeine (OTC drug)
Top 25%

#449 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 Zedoary

What is Zedoary?

  • Digestive upset and bloating
  • Loss of appetite
  • Menstrual discomfort
  • Inflammation and pain
  • Traditional flavoring and tonic

Zedoary is a ginger-family root used in traditional Asian and Indian medicine, mostly for digestion and as a spice. Scientific evidence in humans is very limited, so its benefits are not well proven. Talk with your pharmacist or doctor before using it, and avoid it during pregnancy.

Read the full Zedoary monograph & all interactions
Keep checking

Other Drugs & Zedoary

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

0Major
642Moderate
0Minor
2,187No known interaction
642 Moderate 2,187 No interaction
Moderate

642 interactions

Showing 60 of 642 moderate interactions — see all 642 on the Zedoary page.

No interaction 2,187 drugs checked — show the list

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

Showing the 60 most looked-up of 2,187 medications checked with no known interaction — see the full Zedoary list.

See the full Zedoary interactions page
See every supplement checked against Caffeine (OTC drug), 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
Zedoary monograph › Uses, safety, and every drug interaction in one place Caffeine (OTC drug) supplement interactions › Every supplement checked against Caffeine (OTC drug), ranked by severity 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 Zedoary and Caffeine (OTC drug) Together: Common Questions

Can you take Zedoary with Caffeine (OTC drug)?
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 Zedoary and Caffeine (OTC drug) 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

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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.