Drug & supplement interaction

Bacopa + Chlorpheniramine, Phenylephrine, Phenylpropanolamine, Pyrilamine

Chlorpheniramine, Phenylephrine, Phenylpropanolamine, Pyrilamine brand names: Histalet Forte, Poly Hist Forte, Vanex Forte.

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

Chlorpheniramine, Phenylephrine, Phenylpropanolamine, Pyrilamine 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 CYP3A4 substrates.

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

Bacopa and Chlorpheniramine, Phenylephrine, Phenylpropanolamine, Pyrilamine

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. Chlorpheniramine, Phenylephrine, Phenylpropanolamine, Pyrilamine 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 3A4 (CYP3A4) SUBSTRATES

1 of 2

Why this applies to Chlorpheniramine, Phenylephrine, Phenylpropanolamine, Pyrilamine

Chlorpheniramine, Phenylephrine, Phenylpropanolamine, Pyrilamine falls under CYTOCHROME P450 3A4 (CYP3A4) SUBSTRATES — the group Bacopa interacts with.

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

This combination product mixes two antihistamines (chlorpheniramine and pyrilamine) with two decongestants (phenylephrine and phenylpropanolamine). The idea on file is that bacopa might slow down the CYP3A4 enzyme that helps clear some of these ingredients. If that happened, the levels could creep up a little, which might mean more drowsiness, dry mouth, dizziness, constipation, or a jittery, racing-heart feeling from the decongestant side.

Honestly though, this is a theoretical concern based only on lab studies, and even those results disagree with each other. None of these are prodrugs, so they still work normally. For most people this won't be a big deal, but if you notice extra sleepiness or your heart pounding, check in with your pharmacist or doctor.

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

ANTICHOLINERGIC DRUGS

2 of 2

Chlorpheniramine, Phenylephrine, Phenylpropanolamine, Pyrilamine also falls under ANTICHOLINERGIC DRUGS.

Theoretically, concurrent use might decrease the effectiveness of both agents.
Bacopa seems to inhibit acetylcholinesterase and might increase acetylcholine levels, which could counteract the effects of anticholinergic drugs. Similarly, anticholinergic drugs might counteract the cholinergic effects of bacopa.
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 combo product contains two antihistamines (chlorpheniramine and pyrilamine) along with decongestants. The antihistamines have what we call anticholinergic activity, meaning they block the brain chemical acetylcholine. Bacopa is thought to do the opposite by raising acetylcholine levels. So on paper, the two could work against each other, with bacopa slightly blunting the antihistamine effect (or the antihistamine blunting any memory benefit you hoped for from bacopa).

I want to be honest though: this is a theoretical concern based on how these things work in the lab, not something well documented in real patients. In practice it's unlikely to cause a noticeable problem. If you take both and feel your allergy relief isn't working, or you notice extra drowsiness or dry mouth, just check in with your pharmacist or doctor.

Contact Dr. Brian directly if you have additional questions on this interaction
References
  1. Morgan A, Stevens J. Does Bacopa monnieri improve memory performance in older persons? Results of a randomized, placebo-controlled, double-blind trial. J Altern Complement Med 2010;16:753-9.

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 Chlorpheniramine, Phenylephrine, Phenylpropanolamine, Pyrilamine 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. Chlorpheniramine, Phenylephrine, Phenylpropanolamine, Pyrilamine)
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 Chlorpheniramine, Phenylephrine, Phenylpropanolamine, Pyrilamine

This page covers Bacopa only. If you take other supplements — a multivitamin, a sleep aid, something for joints — the Chlorpheniramine, Phenylephrine, Phenylpropanolamine, Pyrilamine page lists 229 supplements it has a documented interaction with, worst first, each one explained.

The most serious there right now: Activated Charcoal (major), Ephedra (major), Grapefruit (major), Henbane (major) and Lithium (major).

By severity: 10 major · 175 moderate · 44 minor.

From our pharmacist’s overview on the Chlorpheniramine, Phenylephrine, Phenylpropanolamine, Pyrilamine page

“Ephedra is the first thing I would take off the shelf for anyone using chlorpheniramine, phenylephrine, phenylpropanolamine, and pyrilamine (Histalet Forte, Poly Hist Forte, Vanex Forte). This cold and allergy combination contains two decongestants that already raise blood pressure and heart rate, and 44 ingredients on this list, ephed…”

Reviewed by 2 · Jul 18, 2026

Open the Chlorpheniramine, Phenylephrine, Phenylpropanolamine, Pyrilamine 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 Chlorpheniramine, Phenylephrine, Phenylpropanolamine, Pyrilamine 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 Chlorpheniramine, Phenylephrine, 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 Bacopa
Top 10%

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

29 days ago today
Medication Chlorpheniramine, Phenylephrine, Phenylpropanolamine, Pyrilamine
Top 25%

#492 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 Chlorpheniramine, Phenylephrine, 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
Bacopa monograph › Uses, safety, and every drug interaction in one place Chlorpheniramine, Phenylephrine, Phenylpropanolamine, Pyrilamine supplement interactions › Every supplement checked against Chlorpheniramine, Phenylephrine, 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 Bacopa and Chlorpheniramine, Phenylephrine, Phenylpropanolamine, Pyrilamine Together: Common Questions

Can you take Bacopa with Chlorpheniramine, Phenylephrine, 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 Bacopa and Chlorpheniramine, Phenylephrine, Phenylpropanolamine, Pyrilamine?
Chlorpheniramine, Phenylephrine, Phenylpropanolamine, Pyrilamine 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 Chlorpheniramine, Phenylephrine, 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.