Drug & supplement interaction

Anise + Acetaminophen, Caffeine, Codeine

Acetaminophen, Caffeine, Codeine brand names: Gesic C8, Gesic C15, Lenoltec 2, Gesic C30, Lenoltec 3, and others.

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

Acetaminophen, Caffeine, Codeine falls into 3 drug categories that Anise can interact with; the most serious is rated moderate. Theoretically, anise oil might decrease the efficacy of caffeine.

Read the full interaction report
SeverityModerate
LikelihoodPossible
Interactions3
EvidenceD
What do Severity, Likelihood & Evidence mean?
Know someone taking this? Share
Facebook Post Reddit Email
On this page
Interaction report

Anise and Acetaminophen, Caffeine, Codeine

These two interact in 3 distinct ways. Each one is explained separately below.

Why Are There 3 Interactions?

Anise interacts with whole categories of medication. Acetaminophen, Caffeine, Codeine falls into 3 of those categories, so it can interact with Anise in 3 different ways. We’ve listed each one below — your overall risk is driven by the most serious of them (Moderate).

Moderate

CAFFEINE

1 of 3

Why this applies to Acetaminophen, Caffeine, Codeine

Acetaminophen, Caffeine, Codeine falls under CAFFEINE — the group Anise interacts with.

Theoretically, anise oil might decrease the efficacy of caffeine.
Animal research shows that taking anise oil with caffeine decreases the bioavailability of caffeine. Whether this interaction will occur in humans is unclear.
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

Good question! The only interaction we have on file here is between anise and the caffeine part of this combo pill, not the acetaminophen or codeine. In animal studies, anise oil seemed to lower how much caffeine the body absorbed. That means, in theory, the caffeine could feel a bit weaker. Since caffeine is added mostly to give a small boost to pain relief and help you feel more alert, you might notice slightly less of that perk.

Honestly, this is very weak, lab-and-animal-only evidence, and we don't know if it happens in people at all. A cup of anise tea is unlikely to matter. If you regularly use concentrated anise oil, just mention it to your pharmacist so they can keep an eye on things.

Contact Dr. Brian directly if you have additional questions on this interaction
References
  1. Samojlik I, Petkovic S, Stilinovic N, et al. Pharmacokinetic herb-drug interaction between essential oil of aniseed (Pimpinella anisum L., Apiaceae) and acetaminophen and caffeine: A potential risk for clinical practice. Phytother Res 2016;30:253-9.
Moderate

CODEINE

2 of 3

Acetaminophen, Caffeine, Codeine also falls under CODEINE.

Theoretically, anise oil might increase the effects and adverse effects of codeine.
Animal research shows that anise oil increases the analgesic effects of codeine, possibly by inducing its phase I metabolism and increasing conversion to morphine. Whether this interaction occurs in humans is unclear.
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 key thing about this combo pill: the codeine part is a prodrug. It doesn't do much on its own. Your body has to convert it into morphine before you feel pain relief. So anything that speeds up that conversion can make the codeine hit harder.

That's what's being flagged here. In animal studies, anise oil seemed to boost codeine's pain-relieving effect by ramping up its breakdown into morphine. If that held true in people, you might notice stronger effects but also more morphine-type side effects, like drowsiness, constipation, nausea, or slowed breathing. Honestly though, this is theoretical and based only on lab and animal work, not human studies. Cooking spice and a cup of anise tea are very unlikely to matter; concentrated anise oil is the bigger question. When in doubt, run it by your pharmacist.

Contact Dr. Brian directly if you have additional questions on this interaction
References
  1. Samojlik I, Mijatovic V, Petkovic S, et al. The influence of essential oil of aniseed (Pimpinella anisum, L.) on drug effects on the central nervous system. Fitoterapia 2012;83:1466-73. PubMed
Minor

ACETAMINOPHEN (Tylenol, others)

3 of 3
Theoretically, anise oil might decrease the levels and clinical effects of acetaminophen.
Animal research shows that taking anise oil with acetaminophen decreases peak plasma levels of acetaminophen but does not reduce overall bioavailability. Whether this interaction will occur in humans is unclear.
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

Good news here: this is a very mild, mostly theoretical concern. Your medicine combines acetaminophen (a pain and fever reducer), caffeine, and codeine (an opioid for pain). The only piece anise might touch is the acetaminophen. In animal studies, taking concentrated anise oil alongside acetaminophen lowered its peak blood level, meaning it may take a little longer to kick in, but the total amount absorbed didn't really change. We don't even know if this happens in people.

Practically speaking, a cup of anise tea or seeds in your cooking shouldn't matter at all. Concentrated anise essential oil is the only form worth thinking twice about. If you use that regularly, just mention it to your pharmacist or doctor so they can keep an eye on your pain relief.

Contact Dr. Brian directly if you have additional questions on this interaction
References
  1. Samojlik I, Petkovic S, Stilinovic N, et al. Pharmacokinetic herb-drug interaction between essential oil of aniseed (Pimpinella anisum L., Apiaceae) and acetaminophen and caffeine: A potential risk for clinical practice. Phytother Res 2016;30:253-9.

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

Anise Also Interacts With Other Medications

Anise has 192 moderate, 52 minor known drug interactions in our database — the Acetaminophen, Caffeine, Codeine one above is among them. If you take anything else, check it against the full list below.

Moderate 192 Minor 52 No known interaction 2,586 (incl. Acetaminophen, Caffeine, Codeine)
Taking anything else?

Check Another of Your Medications Against Anise

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

Everything else you take

See Every Supplement That Interacts With Acetaminophen, Caffeine, Codeine

This page covers Anise only. If you take other supplements — a multivitamin, a sleep aid, something for joints — the Acetaminophen, Caffeine, Codeine page lists 303 supplements it has a documented interaction with, worst first, each one explained.

The most serious there right now: 1,4-butanediol (major), Activated Charcoal (major), Asarabacca (major), Beer (major) and Ephedra (major).

By severity: 15 major · 244 moderate · 44 minor.

Open the Acetaminophen, Caffeine, Codeine interaction page

One more smart check

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

We hold 465 real supplement products containing Anise, each one broken down to its full ingredient list — and combination products often carry several ingredients besides Anise. Your product may carry other ingredients that interact with Acetaminophen, Caffeine, Codeine too, on top of Anise — 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 Anise and Acetaminophen, Caffeine, Codeine 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 Anise
Top half

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

29 days ago today
Medication Acetaminophen, Caffeine, Codeine
Top 5%

#83 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 Anise

What is Anise?

Anise
  • Digestive upset and bloating
  • Cough and respiratory complaints
  • Sore throat
  • Menstrual discomfort
  • Flavoring agent

Anise is a fragrant, licorice-flavored seed used for centuries to ease digestion and soothe coughs. Most of its health claims are based on tradition and small or laboratory studies rather than strong human research, so evidence is limited. It is generally safe as a food and tea for most adults, but the concentrated essential oil should be used carefully and avoided in pregnancy.

Read the full Anise monograph & all interactions
Keep checking

Other Drugs & Anise

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

0Major
192Moderate
52Minor
2,585No known interaction
192 Moderate 52 Minor 2,585 No interaction
Moderate

192 interactions

Showing 60 of 192 moderate interactions — see all 192 on the Anise page.

Minor

52 interactions

No interaction 2,585 drugs checked — show the list

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

Showing the 60 most looked-up of 2,585 medications checked with no known interaction — see the full Anise list.

See the full Anise interactions page
See every supplement checked against Acetaminophen, Caffeine, Codeine, 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
Anise monograph › Uses, safety, and every drug interaction in one place Acetaminophen, Caffeine, Codeine supplement interactions › Every supplement checked against Acetaminophen, Caffeine, Codeine, 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 Anise and Acetaminophen, Caffeine, Codeine Together: Common Questions

Can you take Anise with Acetaminophen, Caffeine, Codeine?
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 Anise and Acetaminophen, Caffeine, Codeine?
Acetaminophen, Caffeine, Codeine belongs to more than one drug category, and Anise 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 Anise and Acetaminophen, Caffeine, Codeine 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 Acetaminophen, Caffeine, Codeine and Anise?

Our pharmacists answer your medication & supplement questions — free.

Ask a pharmacist

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.