Drug & supplement interaction

Anise + Aspirin, Caffeine, Codeine Phosphate

Aspirin, Caffeine, Codeine Phosphate brand name: Anacin w/ Codeine.

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

Aspirin, Caffeine, Codeine Phosphate falls into 2 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
Interactions2
EvidenceD
What do Severity, Likelihood & Evidence mean?
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Interaction report

Anise and Aspirin, Caffeine, Codeine Phosphate

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

Why Are There 2 Interactions?

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

Moderate

CAFFEINE

1 of 2

Why this applies to Aspirin, Caffeine, Codeine Phosphate

Aspirin, Caffeine, Codeine Phosphate 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

Here's the thing about this combo: your medicine is a three-in-one, with aspirin for pain, codeine for stronger pain relief, and caffeine to give a little boost and help the painkillers along. The interaction we have on file is specifically about that caffeine piece. Some laboratory and animal work suggests anise oil might lower how much caffeine your body actually absorbs, which could make the caffeine portion feel a bit less effective.

I want to be honest with you though, this is theoretical and based only on animal studies, so we really don't know if it happens in people. The caffeine is a minor helper here anyway, not the main event. A cup of anise tea is very unlikely to matter. If you use concentrated anise oil regularly, just mention it to your pharmacist or doctor.

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 2

Aspirin, Caffeine, Codeine Phosphate 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 the codeine in this combo product: it's actually a prodrug. Your body has to convert codeine into morphine before it really works for pain. So anything that speeds up that conversion could mean more morphine in your system from the same dose.

That's where anise comes in. In animal and lab studies only, anise oil seemed to boost how codeine gets activated, which could mean stronger effects and more side effects like drowsiness, dizziness, constipation, or slowed breathing. I want to stress this is theoretical and has never been confirmed in people. A little anise tea or seasoning is very unlikely to matter; concentrated anise essential oil is the bigger question mark. If you use anise supplements regularly, just give your pharmacist a heads-up.

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

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 Aspirin, Caffeine, Codeine Phosphate 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. Aspirin, Caffeine, Codeine Phosphate)
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 Aspirin, Caffeine, Codeine Phosphate

This page covers Anise only. If you take other supplements — a multivitamin, a sleep aid, something for joints — the Aspirin, Caffeine, Codeine Phosphate page lists 398 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 Danshen (major).

By severity: 17 major · 334 moderate · 47 minor.

From our pharmacist’s overview on the Aspirin, Caffeine, Codeine Phosphate page

“Anacin with Codeine combines aspirin, caffeine, and codeine, and each of the three picks up its own supplement problems, so this is a list worth real caution. Just over half of the 398 ingredients here, 202 of them, can add to aspirin's blood-thinning action and raise bleeding risk.”

Reviewed by 2 · Jul 18, 2026

Open the Aspirin, Caffeine, Codeine Phosphate 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 Aspirin, Caffeine, Codeine Phosphate 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 Aspirin, Caffeine, Codeine Phosphate 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

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

29 days ago today
Medication Aspirin, Caffeine, Codeine Phosphate
Steady interest

#1,502 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 Aspirin, Caffeine, Codeine Phosphate, 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 Aspirin, Caffeine, Codeine Phosphate supplement interactions › Every supplement checked against Aspirin, Caffeine, Codeine Phosphate, 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 Aspirin, Caffeine, Codeine Phosphate Together: Common Questions

Can you take Anise with Aspirin, Caffeine, Codeine Phosphate?
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 Anise and Aspirin, Caffeine, Codeine Phosphate?
Aspirin, Caffeine, Codeine Phosphate 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 Aspirin, Caffeine, Codeine Phosphate 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 Aspirin, Caffeine, Codeine Phosphate and Anise?

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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.