Drug & supplement interaction

Evodia + Acetaminophen, Aspirin

Acetaminophen, Aspirin brand name: Gemnisyn.

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

Acetaminophen, Aspirin falls into 3 drug categories that Evodia can interact with; the most serious is rated moderate. Evodia might reduce the levels and clinical effects of CYP1A2 substrates through induction of CYP1A2.

Read the full interaction report
SeverityModerate
LikelihoodProbable
Interactions3
EvidenceD
What do Severity, Likelihood & Evidence mean?
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Interaction report

Evodia and Acetaminophen, Aspirin

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

Why Are There 3 Interactions?

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

Moderate

CYTOCHROME P450 1A2 (CYP1A2) SUBSTRATES

1 of 3

Why this applies to Acetaminophen, Aspirin

Acetaminophen, Aspirin falls under CYTOCHROME P450 1A2 (CYP1A2) SUBSTRATES — the group Evodia interacts with.

Evodia might reduce the levels and clinical effects of CYP1A2 substrates through induction of CYP1A2.
Evodia extract and the evodia constituent rutaecarpine induce hepatic CYP1A2 enzyme activity. Evodia decreases levels of theophylline and caffeine, CYP1A2 substrates, by about 70% in animal models.
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 honest picture with Gemnisyn (acetaminophen plus aspirin) and evodia. Evodia seems to speed up a liver enzyme called CYP1A2. In theory, revving up that enzyme could clear certain drugs out faster and weaken them. For the acetaminophen part, faster processing could mean slightly less pain or fever relief, and one side note worth mentioning is that the way acetaminophen breaks down can affect the liver, so I'd be a bit cautious there.

That said, the only evidence we have is from test tubes and animals, not people, so I wouldn't lose sleep over an occasional dose. Before pairing evodia with this medicine regularly, run it past your pharmacist or doctor so they can look at your full situation.

Contact Dr. Brian directly if you have additional questions on this interaction
References
  1. Ueng YF, Tsai TH, Don MJ, et al. Alteration of the pharmacokinetics of theophylline by rutaecarpine, an alkaloid of the medicinal herb Evodia rutaecarpa, in rats. J Pharm Pharmacol 2005;57:227-32.
  2. Ueng YF, Jan WC, Lin LC, et al. The alkaloid rutaecarpine is a selective inhibitor of cytochrome P450 1A in mouse and human liver microsomes. Drug Metab Dispos 2002;30:349-53. PubMed
  3. Tsai TH, Chang CH, Lin LC. Effects of Evodia rutaecarpa and rutaecarpine on the pharmacokinetics of caffeine in rats. Planta Med 2005;71:640-5.
  4. Lee SK, Kim NH, Lee J, et al. Induction of cytochrome P450s by rutaecarpine and metabolism of rutaecarpine by cytochrome P450s. Planta Med 2004;70:753-7. PubMed
Moderate

ANTICOAGULANT/ANTIPLATELET DRUGS

2 of 3

Acetaminophen, Aspirin also falls under ANTICOAGULANT/ANTIPLATELET DRUGS.

Theoretically, taking evodia with antiplatelet or anticoagulant drugs might increase the risk of bruising and bleeding.
In vitro and animal studies show that rutaecarpine, a constituent of evodia, inhibits platelet aggregation.
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 with Gemnisyn: the aspirin part of it already thins your blood a bit by keeping platelets from clumping together. That's actually how aspirin helps prevent clots. Evodia contains a compound called rutaecarpine that, at least in lab and animal studies, seems to do something similar to platelets. So if you stack the two, you could in theory nudge your bleeding risk a little higher, meaning easier bruising, nosebleeds, or bleeding that takes longer to stop.

I want to be honest, though: this is only seen in test tubes and animals, not in people, so it's more of a theoretical concern than a proven one. I wouldn't lose sleep over it, but since you're already on aspirin, it's worth a quick chat with your pharmacist or doctor before adding evodia.

Contact Dr. Brian directly if you have additional questions on this interaction
References
  1. Sheu JR, Kan YC, Hung WC, et al. The antiplatelet activity of rutaecarpine, an alkaloid isolated from Evodia rutaecarpa, is mediated through inhibition of phospholipase C. Thromb Res 1998;92:53-64. PubMed
  2. Sheu JR, Hung WC, Lee YM, Yen MH. Mechanism of inhibition of platelet aggregation by rutaecarpine, an alkaloid isolated from Evodia rutaecarpa. Eur J Pharmacol 1996;318:469-75. PubMed
  3. Sheu JR, Hung WC, Wu CH, et al. Antithrombotic effect of rutaecarpine, an alkaloid isolated from Evodia rutaecarpa, on platelet plug formation in in vivo experiments. Br J Haematol 2000;110:110-5.
  4. Huang CJ, Huang WC, Lin WT, et al. Rutaecarpine, an alkaloid from Evodia rutaecarpa, can prevent platelet activation in humans and reduce microvascular thrombosis in mice: crucial role of the PI3K/Akt/GSK3ß signal axis through a cyclic nucleotides/VASP-in
Moderate

CYTOCHROME P450 2E1 (CYP2E1) SUBSTRATES

3 of 3

Acetaminophen, Aspirin also falls under CYTOCHROME P450 2E1 (CYP2E1) SUBSTRATES.

Theoretically, evodia might reduce the levels and clinical effects of CYP2E1 substrates through induction of CYP2E1.
Animal research suggests that rutaecarpine, a constituent of evodia, induces CYP2E1 activity. In rats, rutaecarpine increases markers of CYP2E1 activity, and administration of rutaecarpine with chlorzoxazone, a known CYP2E1 substrate, reduces the area under the curve (AUC) of chlorzoxazone by 84% and increases its clearance by 646%.
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 for Gemnisyn, which combines acetaminophen and aspirin. Evodia contains a compound called rutaecarpine that, in animal studies, seems to speed up a liver enzyme called CYP2E1. Acetaminophen is partly handled by that same enzyme, so in theory evodia could clear it a bit faster. For pain or fever relief, that might mean slightly less effect, though this is only based on lab and animal work, not people.

There's a more important wrinkle worth mentioning. When CYP2E1 is revved up, acetaminophen can produce more of a toxic byproduct (NAPQI) that stresses the liver, especially at higher doses or with regular alcohol use. I wouldn't lose sleep over this with culinary amounts, but if you're considering concentrated evodia supplements alongside Gemnisyn, please check with your pharmacist or doctor first.

Contact Dr. Brian directly if you have additional questions on this interaction
References
  1. Bista SR, Lee SK, Thapa D, et al. Effects of oral rutaecarpine on the pharmacokinetics of intravenous chlorzoxazone in rats. Toxicol Res 2008;24(3):195-9. 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

Evodia Also Interacts With Other Medications

Evodia has 949 moderate known drug interactions in our database — the Acetaminophen, Aspirin one above is among them. If you take anything else, check it against the full list below.

Moderate 949 No known interaction 1,881 (incl. Acetaminophen, Aspirin)
Taking anything else?

Check Another of Your Medications Against Evodia

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

Everything else you take

See Every Supplement That Interacts With Acetaminophen, Aspirin

This page covers Evodia only. If you take other supplements — a multivitamin, a sleep aid, something for joints — the Acetaminophen, Aspirin page lists 321 supplements it has a documented interaction with, worst first, each one explained.

The most serious there right now: Activated Charcoal (major), Asarabacca (major), Beer (major), Danshen (major) and Piracetam (major).

By severity: 7 major · 270 moderate · 44 minor.

From our pharmacist’s overview on the Acetaminophen, Aspirin page

“Acetaminophen with aspirin (Gemnisyn) is the kind of pain reliever people take without a second thought, which is exactly why its interaction list deserves genuine care. More than 200 of the 321 ingredients on file thin the blood in some way, and layered on top of aspirin that means a higher chance of bleeding, especially in the stomach.”

Reviewed by 2 · Jul 18, 2026

Open the Acetaminophen, Aspirin interaction page

One more smart check

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

We hold 182 real supplement products containing Evodia, each one broken down to its full ingredient list — and combination products often carry several ingredients besides Evodia. Your product may carry other ingredients that interact with Acetaminophen, Aspirin too, on top of Evodia — 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 Evodia and Acetaminophen, Aspirin 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 Evodia
Top half

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

29 days ago today
Medication Acetaminophen, Aspirin
Top 25%

#339 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 Evodia

What is Evodia?

  • Digestive upset and nausea
  • Headaches
  • Menstrual cramps
  • Abdominal pain
  • Diarrhea

Evodia is a fruit used in traditional Chinese medicine, most often for digestive complaints, headaches, and menstrual pain. Human evidence for these uses is very limited, and it is mostly studied in laboratory and animal research. Talk with a pharmacist or doctor before using it, and avoid it during pregnancy and breastfeeding.

Read the full Evodia monograph & all interactions
Keep checking

Other Drugs & Evodia

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

0Major
949Moderate
0Minor
1,880No known interaction
949 Moderate 1,880 No interaction
Moderate

949 interactions

Showing 60 of 949 moderate interactions — see all 949 on the Evodia page.

No interaction 1,880 drugs checked — show the list

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

Showing the 60 most looked-up of 1,880 medications checked with no known interaction — see the full Evodia list.

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

Can you take Evodia with Acetaminophen, Aspirin?
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 Evodia and Acetaminophen, Aspirin?
Acetaminophen, Aspirin belongs to more than one drug category, and Evodia 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 Evodia and Acetaminophen, Aspirin 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.