Berberine + Acetaminophen, Dextromethorphan, Guaifenesin, Phenylephrine
Acetaminophen, Dextromethorphan, Guaifenesin, Phenylephrine brand name: Conar-A.
Acetaminophen, Dextromethorphan, Guaifenesin, Phenylephrine falls into 3 drug categories that Berberine can interact with; the most serious is rated moderate. Theoretically, berberine might increase serum levels of drugs metabolized by CYP2D6.
Read the full interaction reportBerberine and Acetaminophen, Dextromethorphan, Guaifenesin, Phenylephrine
These two interact in 3 distinct ways. Each one is explained separately below.
Why Are There 3 Interactions?
Berberine interacts with whole categories of medication. Acetaminophen, Dextromethorphan, Guaifenesin, Phenylephrine falls into 3 of those categories, so it can interact with Berberine in 3 different ways. We’ve listed each one below — your overall risk is driven by the most serious of them (Moderate).
CYTOCHROME P450 2D6 (CYP2D6) SUBSTRATES
1 of 3Why this applies to Acetaminophen, Dextromethorphan, Guaifenesin, Phenylephrine
Acetaminophen, Dextromethorphan, Guaifenesin, Phenylephrine falls under CYTOCHROME P450 2D6 (CYP2D6) SUBSTRATES — the group Berberine interacts with.
In vitro research and preliminary clinical evidence show that berberine can inhibit CYP2D6. Theoretically, use of berberine with drugs metabolized by CYP2D6 might increase drug levels and increase the risk of adverse effects.
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.
In this combination cold product, the one ingredient that matters here is dextromethorphan (the cough suppressant). Your body relies on an enzyme called CYP2D6 to clear it. Berberine appears to slow that enzyme down, so dextromethorphan could build up a bit more than usual. That might mean more of its typical effects, like drowsiness, dizziness, or feeling foggy. The acetaminophen, guaifenesin, and phenylephrine pieces are not really affected this way.
Honestly, this is mostly theory backed by lab work and some weak human data, so for a short course of a cold medicine it is unlikely to cause big trouble. Still, if you take berberine daily, it is worth a quick word with your pharmacist before pairing them.
- Chatterjee P, Franklin MR. Human cytochrome p450 inhibition and metabolic-intermediate complex formation by goldenseal extract and its methylenedioxyphenyl components. Drug Metab Dispos 2003;31:1391-7. PubMed
- 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
- Hermann, R. and von, Richter O. Clinical evidence of herbal drugs as perpetrators of pharmacokinetic drug interactions. Planta Med 2012;78(13):1458-1477. PubMed
CYTOCHROME P450 3A4 (CYP3A4) SUBSTRATES
2 of 3Acetaminophen, Dextromethorphan, Guaifenesin, Phenylephrine also falls under CYTOCHROME P450 3A4 (CYP3A4) SUBSTRATES.
In vitro research and preliminary clinical research show that berberine moderately inhibits CYP3A4. Theoretically, use of berberine with drugs metabolized by CYP3A4 might increase drug levels and increase the risk of adverse effects.
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.
This cold and cough combo (Conar-A) contains a few ingredients, and the one that matters most here is the dextromethorphan, the cough suppressant. Berberine may gently slow down a liver enzyme called CYP3A4 that helps clear dextromethorphan from your body. In theory, that could let a bit more build up, which might leave you feeling more drowsy, dizzy, or lightheaded than usual.
The good news is this concern is largely theoretical, based mostly on lab work, and is rated as a moderate, possible interaction. For most people taking a short course for a cold, it is unlikely to cause big problems. Still, since berberine is a concentrated supplement (not a food), I would run it past your pharmacist before combining the two, especially if you notice extra grogginess.
- Wu X, Li Q, Xin H, Yu A, Zhong M. Effects of berberine on the blood concentration of cyclosporin A in renal transplanted recipients: clinical and pharmacokinetic study. Eur J Clin Pharmacol 2005;61:567-72. PubMed
- Budzinski JW, Foster BC, Vandenhoek S, Arnason JT. An in vitro evaluation of human cytochrome P450 3A4 inhibition by selected commercial herbal extracts and tinctures. Phytomedicine 2000;7:273-82. PubMed
- 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
- Hermann, R. and von, Richter O. Clinical evidence of herbal drugs as perpetrators of pharmacokinetic drug interactions. Planta Med 2012;78(13):1458-1477. PubMed
DEXTROMETHORPHAN (Robitussin DM, others)
3 of 3Preliminary 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.
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.
Of the four ingredients in Conar-A, the one that matters here is the cough suppressant dextromethorphan. Your body clears it using a liver enzyme called CYP2D6, and berberine appears to slow that enzyme down. When that happens, dextromethorphan can build up a bit more than usual, which may make its effects and side effects stronger. Think drowsiness, dizziness, or feeling foggy. The acetaminophen, guaifenesin, and phenylephrine pieces are not really affected by this.
The good news is this comes from early, lower-quality research, so it is more of a theoretical caution than a sure thing. Occasional use is unlikely to cause trouble for most people, but if you take berberine daily, mention it to your pharmacist before reaching for this cough and cold combo.
- 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.
Clinically significant. Avoid the combination, or use only under close professional supervision.
Usually worth avoiding or managing — may need monitoring, a dose change, or timing apart.
Generally not serious. Be aware of it and mention it to your pharmacist.
- 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.
- 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.
Berberine Also Interacts With Other Medications
Berberine has 1 major, 1,158 moderate known drug interactions in our database — the Acetaminophen, Dextromethorphan, Guaifenesin, Phenylephrine one above is among them. If you take anything else, check it against the full list below.
Check Another of Your Medications Against Berberine
We haven’t checked that one against Berberine yet — ask our pharmacists directly.
Covers the 2,830 medications we’ve checked against Berberine. Pick one to open its full report.
Questions About Berberine or Acetaminophen, Dextromethorphan, Guaifenesin, Phenylephrine
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, Guaifenesin, Phenylephrine, 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:
- Can You Replace an Evening Apixaban Dose With Berberine? ›
- Can You Take Berberine, Garlic, and NAC With Eliquis? ›
- Can You Take Phentermine With Berberine? ›
- Can You Take Berberine With Methotrexate? ›
Not quite your question? Ask our pharmacists directly — it is free, there is no account required, and answers usually come back within 24 hours.
See Every Supplement That Interacts With Acetaminophen, Dextromethorphan, Guaifenesin, Phenylephrine
This page covers Berberine only. If you take other supplements — a multivitamin, a sleep aid, something for joints — the Acetaminophen, Dextromethorphan, Guaifenesin, Phenylephrine page lists 261 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: 12 major · 206 moderate · 43 minor.
From our pharmacist’s overview on the Acetaminophen, Dextromethorphan, Guaifenesin, Phenylephrine page
“Picture the week someone takes Conar-A (acetaminophen, dextromethorphan, guaifenesin, phenylephrine): a miserable cold, coffee to push through, maybe wine at night or an herbal remedy on top. Those habits are exactly where this list turns serious.”
Reviewed by 2 · Jul 18, 2026
Open the Acetaminophen, Dextromethorphan, Guaifenesin, Phenylephrine interaction page
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, Guaifenesin, Phenylephrine 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:
Where Berberine and Acetaminophen, Dextromethorphan, Guaifenesin, Phenylephrine 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.
#116 of 1,452 supplements looked up here in the last 7 days
#264 of 2,830 medications looked up here in the last 7 days
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.
About Berberine
What is 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.
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.
No drugs match “”.
1 interaction
1,158 interactions
- Diclofenac Sodium ›
- Diltiazem ›
- Nifedipine ›
- Ibuprofen ›
- Diphenhydramine ›
- Aspirin ›
- Hydrocortisone ›
- Insulin (rdna) ›
- Naproxen ›
- Erythromycin ›
- Estradiol ›
- Minocycline ›
- Propranolol ›
- Lidocaine ›
- Guaifenesin ›
- Hydrochlorothiazide ›
- Norethindrone ›
- Testosterone ›
- Verapamil ›
- Levonorgestrel ›
- Prednisone ›
- Quinidine ›
- Dexamethasone ›
- Flurazepam ›
- Glyburide ›
- Insulin (pork) ›
- Triazolam ›
- Zopiclone ›
- Colchicine ›
- Fentanyl ›
- Flurbiprofen ›
- Oxybutynin ›
- Oxycodone ›
- Phenytoin ›
- Prednisolone ›
- Tacrolimus ›
- Temazepam ›
- Budesonide ›
- Carbamazepine ›
- Clindamycin ›
- Dextromethorphan ›
- Diclofenac Potassium ›
- Dipyridamole ›
- Doxorubicin ›
- Fluticasone ›
- Formoterol ›
- Hydralazine ›
- Indomethacin ›
- Insulin (human) ›
- Miconazole ›
- Morphine Sulfate ›
- Nitrazepam ›
- Trimipramine ›
- Amphetamine ›
- Buprenorphine ›
- Conjugated Estrogens ›
- Diazepam ›
- Everolimus ›
- Ivabradine ›
- Ketoprofen ›
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.
- Levothyroxine ›
- Methylphenidate ›
- Ivermectin ›
- Rosuvastatin ›
- Escitalopram ›
- Acetaminophen ›
- Docusate ›
- Hydroxyurea ›
- Valacyclovir ›
- Sumatriptan ›
- Bupropion ›
- Amoxicillin ›
- Acyclovir ›
- Bendamustine ›
- Doxycycline ›
- Methotrexate ›
- Azithromycin ›
- Isotretinoin ›
- Methylene Blue ›
- Ciprofloxacin ›
- Levothyroxine, Liothyronine ›
- Cyclopentolate ›
- Cephalexin ›
- Roxithromycin ›
- Pegunigalsidase Alfa-iwxj ›
- Daptomycin ›
- Hexobarbitone ›
- Dexmethylphenidate ›
- Levothyroxine Sodium ›
- Factor 7a ›
- Thyroid Hormone ›
- Carbidopa, Levodopa ›
- Mitomycin ›
- Levodopa ›
- Ezetimibe ›
- Cefaclor ›
- Phenylephrine ›
- Vancomycin ›
- Lenvatinib ›
- Hethylphenidate Hcl ›
- Dirithromycin ›
- Bentoquatam ›
- Amoxicillin, Clavulanate Potassium ›
- Procainamide ›
- Hydroxychloroquine ›
- Azelaic Acid ›
- Triptorelin ›
- Digoxin ›
- Dextrothyroxine ›
- Lomustine ›
- Pizotifen ›
- Tocainide ›
- Rocuronium ›
- Succimer ›
- Mitomycin C ›
- Paracetamol ›
- Halothane ›
- Chenodiol ›
- Desflurane ›
- Gestodene ›
Showing the 60 most looked-up of 1,670 medications checked with no known interaction — see the full Berberine list.
Sources & How We Checked
Interaction details are evidence-graded and sourced from the Natural Medicines database. The medication overview comes from MedlinePlus.
- Natural Medicines (Therapeutic Research Center) — Evidence-graded clinical reference for vitamins, herbs and supplements — the basis for our interaction data.
- MedlinePlus, U.S. National Library of Medicine — NIH consumer drug information, used for the medication overviews.
- NIH Dietary Supplement Label Database (DSLD) — Official supplement product labels.
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
Acetaminophen, Dextromethorphan, Guaifenesin, Phenylephrine Is Linked to Lower Levels of One Nutrient
Natural Medicines records Acetaminophen, Dextromethorphan, Guaifenesin, Phenylephrine as a medicine that can lower these. This is not an interaction with Berberine — it is a separate effect of the medicine, and it is a reason some people are advised to supplement rather than to avoid one:
Depletion records come from the licensed Natural Medicines database. Do not start a supplement on the strength of this page — ask your pharmacist or doctor whether it applies to you.
Taking Berberine and Acetaminophen, Dextromethorphan, Guaifenesin, Phenylephrine Together: Common Questions
Can you take Berberine with Acetaminophen, Dextromethorphan, Guaifenesin, Phenylephrine?
Why are there 3 interactions listed for Berberine and Acetaminophen, Dextromethorphan, Guaifenesin, Phenylephrine?
How serious is the Berberine and Acetaminophen, Dextromethorphan, Guaifenesin, Phenylephrine interaction?
Written and reviewed by the HelloPharmacist editorial staff. Our editorial policy
Still Have a Question About Acetaminophen, Dextromethorphan, Guaifenesin, Phenylephrine 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.