Drug & supplement interaction

Celery + Acetaminophen, Dextromethorphan, Phenylpropanolamine, Pyrilamine

Acetaminophen, Dextromethorphan, Phenylpropanolamine, Pyrilamine brand name: Theracaps.

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

Acetaminophen, Dextromethorphan, Phenylpropanolamine, Pyrilamine falls into 2 drug categories that Celery can interact with; the most serious is rated moderate. Theoretically, celery might increase levels of drugs metabolized by CYP1A2.

Read the full interaction report
SeverityModerate
LikelihoodPossible
Interactions2
EvidenceD
What do Severity, Likelihood & Evidence mean?
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Interaction report

Celery and Acetaminophen, Dextromethorphan, Phenylpropanolamine, Pyrilamine

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

Why Are There 2 Interactions?

Celery interacts with whole categories of medication. Acetaminophen, Dextromethorphan, Phenylpropanolamine, Pyrilamine falls into 2 of those categories, so it can interact with Celery in 2 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 2

Why this applies to Acetaminophen, Dextromethorphan, Phenylpropanolamine, Pyrilamine

Acetaminophen, Dextromethorphan, Phenylpropanolamine, Pyrilamine falls under CYTOCHROME P450 1A2 (CYP1A2) SUBSTRATES — the group Celery interacts with.

Theoretically, celery might increase levels of drugs metabolized by CYP1A2.
In vitro and animal research suggests that constituents of celery can inhibit CYP1A2. This effect has not been reported in humans.
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

This combination product (Theracaps) is a cold and cough remedy with acetaminophen, dextromethorphan, phenylpropanolamine, and pyrilamine. The idea here is that compounds in celery might slow down a liver enzyme called CYP1A2, which helps clear some of these ingredients. If that enzyme works slower, a little more of the drug could hang around, which in theory might bump up effects like drowsiness, dizziness, or feeling foggy from the dextromethorphan and pyrilamine.

Here's the honest part: this is only a theoretical concern. It comes from lab and animal studies, and it has never actually been shown in people. Eating celery as food is very unlikely to matter. If you take concentrated celery seed supplements regularly, just mention it to your pharmacist or doctor to be safe.

Contact Dr. Brian directly if you have additional questions on this interaction
References
  1. Peterson, S., Lampe, J. W., Bammler, T. K., Gross-Steinmeyer, K., and Eaton, D. L. Apiaceous vegetable constituents inhibit human cytochrome P-450 1A2 (hCYP1A2) activity and hCYP1A2-mediated mutagenicity of aflatoxin B1. Food Chem.Toxicol. 2006;44(9):147 PubMed
Minor

ACETAMINOPHEN (Tylenol, others)

2 of 2
Theoretically, celery juice might increase the effects and side effects of acetaminophen.
Animal research suggests that concomitant use of celery juice plus acetaminophen prolongs the effects of acetaminophen. This effect has been attributed to a decrease in hepatic cytochrome P450 activity. However, other animal research shows that pretreatment with celery root extract protects against acetaminophen-induced acute liver failure. These effects have not been reported in humans.
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

Your Theracaps is a combo cold product, and the piece this note focuses on is the acetaminophen in it. In some animal studies, concentrated celery juice seemed to slow down the liver enzymes that clear acetaminophen. In theory, that could let acetaminophen hang around a little longer and feel slightly stronger. Interestingly, other animal work suggested celery root might actually protect the liver from acetaminophen. So the lab results pull in opposite directions.

The honest bottom line: this has never been shown in people, and it is rated a minor interaction. Eating celery as food is not a concern. If you regularly take strong celery supplements, just mention it to your pharmacist, and as always, do not exceed the acetaminophen dose on the label.

Contact Dr. Brian directly if you have additional questions on this interaction
References
  1. Jakovljevic, V., Raskovic, A., Popovic, M., and Sabo, J. The effect of celery and parsley juices on pharmacodynamic activity of drugs involving cytochrome P450 in their metabolism. Eur.J Drug Metab Pharmacokinet. 2002;27(3):153-156. PubMed
  2. Emad AM, Ali SF, Abdel-Rahman EA, et al. Anti-inflammatory and antioxidant effects of Apium graveolens L. extracts mitigate against fatal acetaminophen-induced acute liver toxicity. J Food Biochem 2020:e13399. Online ahead of print.

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

Celery Also Interacts With Other Medications

Celery has 448 moderate, 202 minor known drug interactions in our database — the Acetaminophen, Dextromethorphan, Phenylpropanolamine, Pyrilamine one above is among them. If you take anything else, check it against the full list below.

Moderate 448 Minor 202 No known interaction 2,180 (incl. Acetaminophen, Dextromethorphan, Phenylpropanolamine, Pyrilamine)
Taking anything else?

Check Another of Your Medications Against Celery

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

Everything else you take

See Every Supplement That Interacts With Acetaminophen, Dextromethorphan, Phenylpropanolamine, Pyrilamine

This page covers Celery only. If you take other supplements — a multivitamin, a sleep aid, something for joints — the Acetaminophen, Dextromethorphan, Phenylpropanolamine, Pyrilamine page lists 282 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), Ephedra (major) and Grapefruit (major).

By severity: 14 major · 223 moderate · 45 minor.

From our pharmacist’s overview on the Acetaminophen, Dextromethorphan, Phenylpropanolamine, Pyrilamine page

“Of everything on this page, ephedra worries me most for anyone using Theracaps (acetaminophen, dextromethorphan, phenylpropanolamine, and pyrilamine), because the decongestant in this cold formula is itself a stimulant. Adding ephedra or any of the 44 stimulant entries can push blood pressure and heart rate to unsafe levels.”

Reviewed by 2 · Jul 18, 2026

Open the Acetaminophen, Dextromethorphan, Phenylpropanolamine, Pyrilamine interaction page

One more smart check

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

We hold 1,687 real supplement products containing Celery, each one broken down to its full ingredient list — and combination products often carry several ingredients besides Celery. Your product may carry other ingredients that interact with Acetaminophen, Dextromethorphan, Phenylpropanolamine, Pyrilamine too, on top of Celery — 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 Celery and Acetaminophen, Dextromethorphan, Phenylpropanolamine, Pyrilamine 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 Celery
Top 25%

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

29 days ago today
Medication Acetaminophen, Dextromethorphan, Phenylpropanolamine, Pyrilamine
Steady interest

#1,531 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 Celery

What is Celery?

Celery
  • High blood pressure
  • Fluid retention (diuretic)
  • Joint pain and inflammation
  • Anxiety and sleep
  • Digestive support

Celery is a common vegetable that is also taken as a seed extract or oil supplement, mainly for blood pressure, fluid retention, and joint discomfort. Human evidence for these supplement uses is limited and mostly preliminary, so it should not replace proven treatments. Celery is generally safe as food, but concentrated supplements and possible allergic reactions warrant caution.

Read the full Celery monograph & all interactions
Keep checking

Other Drugs & Celery

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

0Major
448Moderate
202Minor
2,179No known interaction
448 Moderate 202 Minor 2,179 No interaction
Moderate

448 interactions

Showing 60 of 448 moderate interactions — see all 448 on the Celery page.

Minor

202 interactions

Showing 60 of 202 minor interactions — see all 202 on the Celery page.

No interaction 2,179 drugs checked — show the list

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

Showing the 60 most looked-up of 2,179 medications checked with no known interaction — see the full Celery list.

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

Can you take Celery with Acetaminophen, Dextromethorphan, Phenylpropanolamine, Pyrilamine?
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 Celery and Acetaminophen, Dextromethorphan, Phenylpropanolamine, Pyrilamine?
Acetaminophen, Dextromethorphan, Phenylpropanolamine, Pyrilamine belongs to more than one drug category, and Celery 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 Celery and Acetaminophen, Dextromethorphan, Phenylpropanolamine, Pyrilamine 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.