Drug & supplement interaction

Berberine + acetaminophen, dextromethorphan, doxylamine

acetaminophen, dextromethorphan, doxylamine brand name: NyQuil.

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

acetaminophen, dextromethorphan, doxylamine falls into 2 drug categories that Berberine can interact with; the most serious is rated moderate. Theoretically, berberine might increase the sedative effects of CNS depressants.

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

Berberine and acetaminophen, dextromethorphan, doxylamine

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

Why Are There 2 Interactions?

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

Moderate

CNS DEPRESSANTS

1 of 2

Why this applies to acetaminophen, dextromethorphan, doxylamine

acetaminophen, dextromethorphan, doxylamine falls under CNS DEPRESSANTS — the group Berberine interacts with.

Theoretically, berberine might increase the sedative effects of CNS depressants.
Animal research suggests that berberine may have sedative effects. Theoretically, use of berberine along with CNS depressants might produce additive therapeutic and adverse effects.
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

If you're reaching for NyQuil while taking berberine, the part to watch is the doxylamine (the antihistamine) and to a lesser degree the dextromethorphan. Both can already make you drowsy. Some early animal research hints that berberine may have a mild calming or sedating effect of its own, so in theory the two together could leave you feeling extra sleepy, foggy, or slow to react.

I want to be honest about the evidence here: this is based on lab and animal studies, not solid human data, so it may not amount to much in real life. Still, go easy until you know how you feel, avoid driving if you're groggy, and don't double up on other sleep aids. The acetaminophen portion isn't the concern. Check with your pharmacist if you take NyQuil often.

Contact Dr. Brian directly if you have additional questions on this interaction
References
  1. Janbaz KH, Gilani AH. Studies on preventive and curative effects of berberine on chemical-induced hepatotoxicity in rodents. Fitoterapia 2000;71:25-33.. PubMed
  2. Shanbhag, S. M., Kulkarni, H. J., and Gaitonde, B. B. Pharmacological actions of berberine on the central nervous system. Jpn.J Pharmacol 1970;20(4):482-487. PubMed
  3. Peng, W. H., Hsieh, M. T., and Wu, C. R. Effect of long-term administration of berberine on scopolamine-induced amnesia in rats. Jpn J Pharmacol 1997;74(3):261-266. DOI
  4. Sabir M and Bhide NK. Study of some pharmacological actions of berberine. Ind J Physiol & Pharmac 1971;15(3):111-132.
Moderate

DEXTROMETHORPHAN (Robitussin DM, others)

2 of 2
Theoretically, berberine may increase serum levels of dextromethorphan.
Preliminary clinical research shows that berberine can inhibit cytochrome P450 2D6 (CYP2D6) activity and reduce the metabolism of dextromethorphan. This may increase the effects and side effects of dextromethorphan.
Severity Moderate Likelihood Possible Evidence B

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 piece to watch with NyQuil: it contains dextromethorphan, the cough suppressant. Your body clears dextromethorphan mainly through a liver enzyme called CYP2D6, and early research suggests berberine can slow that enzyme down. When the cleanup slows, dextromethorphan can build up a bit higher than usual, which may make its effects and side effects stronger, things like dizziness, drowsiness, or feeling foggy or lightheaded.

This is still fairly preliminary, so don't panic. But NyQuil already has doxylamine (an antihistamine) on board, so the combined drowsiness could be more noticeable. If you take berberine regularly, check with your pharmacist or doctor before pairing it with NyQuil, and don't change anything on your own.

Contact Dr. Brian directly if you have additional questions on this interaction
References
  1. Guo, Y., Chen, Y., Tan, Z. R., Klaassen, C. D., and Zhou, H. H. Repeated administration of berberine inhibits cytochromes P450 in humans. Eur J Clin Pharmacol 2012;68(2):213-217. 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

Berberine Also Interacts With Other Medications

Berberine has 1 major, 1,158 moderate known drug interactions in our database — the acetaminophen, dextromethorphan, doxylamine one above is among them. If you take anything else, check it against the full list below.

Major 1 Moderate 1,158 No known interaction 1,671 (incl. acetaminophen, dextromethorphan, doxylamine)
Taking anything else?

Check Another of Your Medications Against Berberine

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

From our Q&A

Questions About Berberine or acetaminophen, dextromethorphan, doxylamine

These are real questions from readers, answered by the pharmacists at HelloPharmacist — written by a person, not generated from a database. Each one covers Berberine or acetaminophen, dextromethorphan, doxylamine, not necessarily both, but if one is close to what you were about to ask it will usually go further than a database entry can:

Not quite your question? Ask our pharmacists directly — it is free, there is no account required, and answers usually come back within 24 hours.

Everything else you take

See Every Supplement That Interacts With acetaminophen, dextromethorphan, doxylamine

This page covers Berberine only. If you take other supplements — a multivitamin, a sleep aid, something for joints — the acetaminophen, dextromethorphan, doxylamine page lists 106 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), Beer (major), Gamma-hydroxybutyrate (ghb) (major) and Grapefruit (major).

By severity: 8 major · 78 moderate · 20 minor.

From our pharmacist’s overview on the acetaminophen, dextromethorphan, doxylamine page

“NyQuil (acetaminophen, dextromethorphan, doxylamine) is designed to make you drowsy, and that is exactly where most of its supplement interactions live. Seventy-eight of the 106 ingredients on this list add to its sedation, and the eight rated major, alcohol and kava among them, can push a nighttime cold remedy toward serious depressio…”

Reviewed by 2 · Jul 18, 2026

Open the acetaminophen, dextromethorphan, doxylamine interaction page

One more smart check

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

We hold 908 real supplement products containing Berberine, each one broken down to its full ingredient list — and combination products often carry several ingredients besides Berberine. Your product may carry other ingredients that interact with acetaminophen, dextromethorphan, doxylamine too, on top of Berberine — 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 Berberine and acetaminophen, dextromethorphan, doxylamine 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 Berberine
Top 10%

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

29 days ago today
Medication acetaminophen, dextromethorphan, doxylamine
Top 25%

#292 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 Berberine

What is Berberine?

Berberine
  • Blood sugar control
  • High cholesterol
  • Heart and metabolic health
  • Digestive upset
  • Antimicrobial support
  • Weight management

Berberine is a yellow plant compound that has shown promise for lowering blood sugar and cholesterol in some studies, but the quality of research varies and it is not a replacement for prescribed medicine. It can cause stomach upset and should be avoided during pregnancy and breastfeeding. Always check with your pharmacist or doctor before starting it, especially if you take other medications.

Read the full Berberine monograph & all interactions
Keep checking

Other Drugs & Berberine

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

1Major
1,158Moderate
0Minor
1,670No known interaction
1 Major 1,158 Moderate 1,670 No interaction
Major

1 interaction

Moderate

1,158 interactions

Showing 60 of 1,158 moderate interactions — see all 1,158 on the Berberine page.

No interaction 1,670 drugs checked — show the list

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

Showing the 60 most looked-up of 1,670 medications checked with no known interaction — see the full Berberine list.

See the full Berberine interactions page
See every supplement checked against acetaminophen, dextromethorphan, doxylamine, 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
Berberine monograph › Uses, safety, and every drug interaction in one place acetaminophen, dextromethorphan, doxylamine supplement interactions › Every supplement checked against acetaminophen, dextromethorphan, doxylamine, 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 Berberine and acetaminophen, dextromethorphan, doxylamine Together: Common Questions

Can you take Berberine with acetaminophen, dextromethorphan, doxylamine?
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 Berberine and acetaminophen, dextromethorphan, doxylamine?
acetaminophen, dextromethorphan, doxylamine belongs to more than one drug category, and Berberine 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 Berberine and acetaminophen, dextromethorphan, doxylamine 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, dextromethorphan, doxylamine and Berberine?

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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.