Drug & supplement interaction

Bacopa + Acetaminophen, Dextromethorphan, Guaifenesin, Phenylephrine

Acetaminophen, Dextromethorphan, Guaifenesin, Phenylephrine brand name: Conar-A.

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

Acetaminophen, Dextromethorphan, Guaifenesin, Phenylephrine falls into 2 drug categories that Bacopa can interact with; the most serious is rated moderate. Theoretically, bacopa might increase the levels and adverse effects of CYP1A2 substrates.

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

Bacopa and Acetaminophen, Dextromethorphan, Guaifenesin, Phenylephrine

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

Why Are There 2 Interactions?

Bacopa interacts with whole categories of medication. Acetaminophen, Dextromethorphan, Guaifenesin, Phenylephrine falls into 2 of those categories, so it can interact with Bacopa 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, Guaifenesin, Phenylephrine

Acetaminophen, Dextromethorphan, Guaifenesin, Phenylephrine falls under CYTOCHROME P450 1A2 (CYP1A2) SUBSTRATES — the group Bacopa interacts with.

Theoretically, bacopa might increase the levels and adverse effects of CYP1A2 substrates.
Research on the effects of bacopa extracts on CYP1A2 enzymes is conflicting. Some in vitro evidence shows that bacopa extract can moderately and non-competitively inhibit CYP1A2, while other in vitro evidence suggests that any effect is unlikely to be clinically significant.
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 cold and cough product (Conar-A) contains four ingredients, and the concern here is mostly theoretical. In lab studies, bacopa might slightly slow down a liver enzyme called CYP1A2. If that happened in your body, certain ingredients could clear a little more slowly and build up. In practice, though, the research is mixed and several studies suggest any effect is too small to matter.

If levels did edge up, you might notice more drowsiness or dizziness from the dextromethorphan, or a bit more jitteriness or raised blood pressure from the phenylephrine. None of these ingredients are activated by this enzyme, so bacopa would not make them weaker. The evidence is weak (lab and animal only), so I would not lose sleep over it. Still, if you take bacopa daily, it is worth a quick chat with your pharmacist before combining them.

Contact Dr. Brian directly if you have additional questions on this interaction
References
  1. Kar A, Pandit S, Mukherjee K, Bahadur S, Mukherjee PK. Safety assessment of selected medicinal food plants used in Ayurveda through CYP450 enzyme inhibition study. J Sci Food Agric 2017;97(1):333-40. doi: 10.1002/jsfa.7739. PubMed
  2. Ramasamy S, Kiew LV, Chung LY. Inhibition of human cytochrome P450 enzymes by Bacopa monnieri standardized extract and constituents. Molecules 2014;19(2):2588-601. PubMed
Moderate

CYTOCHROME P450 3A4 (CYP3A4) SUBSTRATES

2 of 2

Acetaminophen, Dextromethorphan, Guaifenesin, Phenylephrine also falls under CYTOCHROME P450 3A4 (CYP3A4) SUBSTRATES.

Theoretically, bacopa might increase the levels and adverse effects of CYP3A4 substrates.
Research on the effects of bacopa extracts on CYP3A4 enzymes is conflicting. Some in vitro evidence suggests that bacopa extract can moderately and competitively inhibit CYP3A4, while other in vitro evidence suggests that any effect is unlikely to be clinically significant.
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

Your cold and cough combo (Conar-A) contains several ingredients, and a couple of them, especially dextromethorphan, get cleared in part by a liver enzyme called CYP3A4. The thinking here is that bacopa might slow that enzyme down a bit, which could let those medicines build up a little more than usual. If that happened, you might notice more of dextromethorphan's effects, like drowsiness, dizziness, or feeling foggy.

Here's the honest part: this concern comes only from lab and test-tube studies, and even those disagree with each other. In real people, a short course of cold medicine alongside bacopa is unlikely to cause trouble. Still, if you take bacopa regularly, it's worth a quick word with your pharmacist or doctor just to be safe.

Contact Dr. Brian directly if you have additional questions on this interaction
References
  1. Kar A, Pandit S, Mukherjee K, Bahadur S, Mukherjee PK. Safety assessment of selected medicinal food plants used in Ayurveda through CYP450 enzyme inhibition study. J Sci Food Agric 2017;97(1):333-40. doi: 10.1002/jsfa.7739. PubMed
  2. Ramasamy S, Kiew LV, Chung LY. Inhibition of human cytochrome P450 enzymes by Bacopa monnieri standardized extract and constituents. Molecules 2014;19(2):2588-601. 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

Bacopa Also Interacts With Other Medications

Bacopa has 916 moderate, 13 minor 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.

Moderate 916 Minor 13 No known interaction 1,901 (incl. Acetaminophen, Dextromethorphan, Guaifenesin, Phenylephrine)
Taking anything else?

Check Another of Your Medications Against Bacopa

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

Everything else you take

See Every Supplement That Interacts With Acetaminophen, Dextromethorphan, Guaifenesin, Phenylephrine

This page covers Bacopa 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

One more smart check

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

We hold 1,420 real supplement products containing Bacopa, each one broken down to its full ingredient list — and combination products often carry several ingredients besides Bacopa. Your product may carry other ingredients that interact with Acetaminophen, Dextromethorphan, Guaifenesin, Phenylephrine too, on top of Bacopa — 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 Bacopa 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.

Supplement Bacopa
Top 10%

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

29 days ago today
Medication Acetaminophen, Dextromethorphan, Guaifenesin, Phenylephrine
Top 10%

#214 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 Bacopa

What is Bacopa?

Bacopa
  • Memory and cognitive support
  • Anxiety and stress
  • ADHD symptoms
  • Age-related memory decline
  • General brain health

Bacopa is an Ayurvedic herb most often used for memory and thinking. Some small studies suggest it may modestly help memory when taken regularly for several weeks, but the evidence is limited and quality varies. It is generally well tolerated but can cause stomach upset, and it should be avoided in pregnancy and breastfeeding due to a lack of safety data.

Read the full Bacopa monograph & all interactions
Keep checking

Other Drugs & Bacopa

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

0Major
916Moderate
13Minor
1,900No known interaction
916 Moderate 13 Minor 1,900 No interaction
Moderate

916 interactions

Showing 60 of 916 moderate interactions — see all 916 on the Bacopa page.

Minor

13 interactions

No interaction 1,900 drugs checked — show the list

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

Showing the 60 most looked-up of 1,900 medications checked with no known interaction — see the full Bacopa list.

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

Can you take Bacopa with Acetaminophen, Dextromethorphan, Guaifenesin, Phenylephrine?
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 Bacopa and Acetaminophen, Dextromethorphan, Guaifenesin, Phenylephrine?
Acetaminophen, Dextromethorphan, Guaifenesin, Phenylephrine belongs to more than one drug category, and Bacopa 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 Bacopa and Acetaminophen, Dextromethorphan, Guaifenesin, Phenylephrine 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.