Drug & supplement interaction

Winter Cherry + Acetaminophen, Phenylpropanolamine

Acetaminophen, Phenylpropanolamine brand name: Tetra Caps.

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

Winter Cherry has a moderate interaction with Acetaminophen, Phenylpropanolamine. In vitro, winter cherry extract inhibited levels of cytochrome P450 2E1 (CYP2E1).

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

Winter Cherry and Acetaminophen, Phenylpropanolamine

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

Moderate

CYTOCHROME P450 2E1 (CYP2E1) SUBSTRATES

Why this applies to Acetaminophen, Phenylpropanolamine

Acetaminophen, Phenylpropanolamine falls under CYTOCHROME P450 2E1 (CYP2E1) SUBSTRATES — the group Winter Cherry interacts with.

In vitro, winter cherry extract inhibited levels of cytochrome P450 2E1 (CYP2E1). Theoretically, winter cherry might inhibit the metabolism and increase the effects and side effects of CYP2E1 substrates.
Some drugs metabolized by CYP2E1 include acetaminophen, chlorzoxazone (Parafon Forte), ethanol, theophylline, and anesthetics such as enflurane (Ethrane), halothane (Fluothane), isoflurane (Forane), methoxyflurane (Penthrane).
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 the acetaminophen part of Tetra Caps. Your liver uses an enzyme called CYP2E1 to help break down acetaminophen. In a lab dish, Winter Cherry (ashwagandha) slowed that enzyme down. In theory, that could mean a bit more acetaminophen hangs around than usual.

I want to be honest with you though: this is based only on test-tube work, not real people, so it's a weak, mostly theoretical concern. Normal acetaminophen doses are unlikely to be a problem. The main thing I'd watch is not exceeding the daily acetaminophen limit, since this drug is hard on the liver in large amounts. If you take ashwagandha regularly or have liver concerns, run it by your pharmacist or doctor first.

Contact Dr. Brian directly if you have additional questions on this interaction
References
  1. Hu XF, Zhang Q, Zhang PP, et al. Evaluation of in vitro/in vivo anti-diabetic effects and identification of compounds from Physalis alkekengi. Fitoterapia. 2018;127:129-137. 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

Winter Cherry Also Interacts With Other Medications

Winter Cherry has 155 moderate known drug interactions in our database — the Acetaminophen, Phenylpropanolamine one above is one of them. If you take anything else, check it against the full list below.

Moderate 155 No known interaction 2,675 (incl. Acetaminophen, Phenylpropanolamine)
Taking anything else?

Check Another of Your Medications Against Winter Cherry

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

Everything else you take

See Every Supplement That Interacts With Acetaminophen, Phenylpropanolamine

This page covers Winter Cherry only. If you take other supplements — a multivitamin, a sleep aid, something for joints — the Acetaminophen, Phenylpropanolamine page lists 196 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 Peyote (major).

By severity: 9 major · 148 moderate · 39 minor.

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

“Tetra Caps combines acetaminophen with phenylpropanolamine, an older stimulant decongestant, and that pairing gives this list real teeth. Nine of the 196 supplement and herbal interactions on file are rated major, and they cluster around the drug's two ingredients.”

Reviewed by 2 · Jul 18, 2026

Open the Acetaminophen, Phenylpropanolamine interaction page

How much people look this up

Where Winter Cherry and Acetaminophen, Phenylpropanolamine 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 Winter Cherry
Steady interest

#1,080 of 1,452 supplements looked up here in the last 7 days

29 days ago today
Medication Acetaminophen, Phenylpropanolamine
Steady interest

#1,650 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 Winter Cherry

What is Winter Cherry?

  • Stress and anxiety
  • Fatigue and low energy
  • Sleep support
  • General vitality and tonic
  • Athletic performance

Winter Cherry is another name for ashwagandha (Withania somnifera), an herb long used in Ayurvedic medicine, most often for stress, sleep, and energy. Some small studies suggest it may help with stress and anxiety, but the evidence is still limited and not definitive. It is generally well tolerated short-term, but pregnant women should avoid it, and anyone with a health condition should check with a pharmacist or doctor first.

Read the full Winter Cherry monograph & all interactions
Keep checking

Other Drugs & Winter Cherry

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

0Major
155Moderate
0Minor
2,674No known interaction
155 Moderate 2,674 No interaction
Moderate

155 interactions

Showing 60 of 155 moderate interactions — see all 155 on the Winter Cherry page.

No interaction 2,674 drugs checked — show the list

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

Showing the 60 most looked-up of 2,674 medications checked with no known interaction — see the full Winter Cherry list.

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

Can you take Winter Cherry with Acetaminophen, Phenylpropanolamine?
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 Winter Cherry and Acetaminophen, Phenylpropanolamine 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, Phenylpropanolamine and Winter Cherry?

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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.