Drug & supplement interaction

Beta-methylphenethylamine (bmpea) + Dextromethorphan HBr, Phenylephrine HCl

Dextromethorphan HBr, Phenylephrine HCl brand name: Vicks Formula 44D Cough & Head Congestion Relief.

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

Dextromethorphan HBr, Phenylephrine HCl falls into 3 drug categories that Beta-methylphenethylamine (bmpea) can interact with; the most serious is rated moderate. Theoretically, BMPEA might increase the levels and clinical effects of CYP2D6 substrates.

Read the full interaction report
SeverityModerate
LikelihoodPossible
Interactions3
EvidenceD
What do Severity, Likelihood & Evidence mean?
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Interaction report

Beta-methylphenethylamine (bmpea) and Dextromethorphan HBr, Phenylephrine HCl

These two interact in 3 distinct ways. Each one is explained separately below.

Why Are There 3 Interactions?

Beta-methylphenethylamine (bmpea) interacts with whole categories of medication. Dextromethorphan HBr, Phenylephrine HCl falls into 3 of those categories, so it can interact with Beta-methylphenethylamine (bmpea) in 3 different ways. We’ve listed each one below — your overall risk is driven by the most serious of them (Moderate).

Moderate

CYTOCHROME P450 2D6 (CYP2D6) SUBSTRATES

1 of 3

Why this applies to Dextromethorphan HBr, Phenylephrine HCl

Dextromethorphan HBr, Phenylephrine HCl falls under CYTOCHROME P450 2D6 (CYP2D6) SUBSTRATES — the group Beta-methylphenethylamine (bmpea) interacts with.

Theoretically, BMPEA might increase the levels and clinical effects of CYP2D6 substrates.
In vitro research shows that BMPEA strongly inhibits CYP2D6.
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 your Vicks Formula 44D. The dextromethorphan (the cough suppressant) is cleared from your body mostly by a liver enzyme called CYP2D6. Lab studies suggest BMPEA can block that enzyme, so in theory dextromethorphan could build up and hit harder than expected. That might mean more drowsiness, dizziness, confusion, or feeling jittery and off-balance.

I want to be honest though: this is a theoretical concern based on test-tube data, not real patient cases. On top of that, both BMPEA and the phenylephrine in this product are stimulants that can push up your heart rate and blood pressure, so stacking them isn't ideal. BMPEA itself is best avoided. If you're using both, please check with your pharmacist or doctor first.

Contact Dr. Brian directly if you have additional questions on this interaction
References
  1. Liu Y, Santillo MF. Cytochrome P450 2D6 and 3A4 enzyme inhibition by amine stimulants in dietary supplements. Drug Test Anal. 2016;8(3-4):307-10. PubMed
Moderate

CYTOCHROME P450 3A4 (CYP3A4) SUBSTRATES

2 of 3

Dextromethorphan HBr, Phenylephrine HCl also falls under CYTOCHROME P450 3A4 (CYP3A4) SUBSTRATES.

Theoretically, BMPEA might increase the levels and clinical effects of CYP3A4 substrates.
In vitro research shows that BMPEA inhibits CYP3A4 by up to 37%.
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 of it. This cough and congestion product contains dextromethorphan (a cough suppressant) and phenylephrine (a decongestant). BMPEA is a synthetic amphetamine-like stimulant, and lab studies suggest it may modestly slow down CYP3A4, one of the enzymes that helps clear dextromethorphan. In theory, that could let dextromethorphan build up a bit, leading to more drowsiness, dizziness, or feeling spacey.

Honestly, my bigger concern is the overlap in stimulant effects. BMPEA can raise your heart rate and blood pressure, and phenylephrine does the same thing. Stacking them could push your blood pressure higher or cause a racing heart. This interaction is theoretical, but BMPEA itself is best avoided. Please check with your pharmacist before combining them.

Contact Dr. Brian directly if you have additional questions on this interaction
References
  1. Liu Y, Santillo MF. Cytochrome P450 2D6 and 3A4 enzyme inhibition by amine stimulants in dietary supplements. Drug Test Anal. 2016;8(3-4):307-10. PubMed
Moderate

STIMULANT DRUGS

3 of 3

Dextromethorphan HBr, Phenylephrine HCl also falls under STIMULANT DRUGS.

Theoretically, taking BMPEA with other stimulant drugs might increase the risk of adverse cardiovascular effects.
BMPEA is thought to have stimulant effects, including cardiovascular effects such as hypertension, tachycardia, and cardiac arrest.
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 thing about this combo: the phenylephrine in your Vicks Formula 44D is a decongestant that tightens up blood vessels, which can nudge your blood pressure and heart rate upward on its own. BMPEA is a stimulant that's chemically related to amphetamine, so it can do the very same thing. Stack the two together and those effects may add up, raising the risk of a faster heartbeat, palpitations, headache, or a spike in blood pressure.

I'll be honest, this concern is based on how these compounds are expected to behave rather than solid human studies, so it's theoretical. Still, BMPEA isn't a well-vetted ingredient and regulators have flagged it. I'd skip it and check with your pharmacist or doctor before pairing it with any decongestant product.

Contact Dr. Brian directly if you have additional questions on this interaction
References
  1. Cohen PA, Bloszies C, Yee C, Gerona R. An amphetamine isomer whose efficacy and safety in humans has never been studied, ß-methylphenylethylamine (BMPEA), is found in multiple dietary supplements. Drug Test Anal. 2015 Apr 7. PubMed
  2. Brown DH, Hansson R, Oosthuizen F, et al. ß-Methylphenylethylamines: common fragmentation pathways with amphetamines in electrospray ionization collision-induced dissociation. Drug Test Anal 2016;8:344-50.

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

Beta-methylphenethylamine (bmpea) Also Interacts With Other Medications

Beta-methylphenethylamine (bmpea) has 812 moderate known drug interactions in our database — the Dextromethorphan HBr, Phenylephrine HCl one above is among them. If you take anything else, check it against the full list below.

Moderate 812 No known interaction 2,018 (incl. Dextromethorphan HBr, Phenylephrine HCl)
Taking anything else?

Check Another of Your Medications Against Beta-methylphenethylamine (bmpea)

Covers the 2,830 medications we’ve checked against Beta-methylphenethylamine (bmpea). Pick one to open its full report.

Everything else you take

See Every Supplement That Interacts With Dextromethorphan HBr, Phenylephrine HCl

This page covers Beta-methylphenethylamine (bmpea) only. If you take other supplements — a multivitamin, a sleep aid, something for joints — the Dextromethorphan HBr, Phenylephrine HCl page lists 197 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), Lithium (major) and Peyote (major).

By severity: 8 major · 148 moderate · 41 minor.

From our pharmacist’s overview on the Dextromethorphan HBr, Phenylephrine HCl page

“The supplement interactions with Dextromethorphan HBr and Phenylephrine HCl (Vicks Formula 44D) deserve real respect, and the small cluster of major-rated ones should be understood before you reach for the bottle. Phenylephrine is a stimulant-type decongestant, so anything with caffeine (coffee, tea, cola nut) or ephedrine-like herbs s…”

Reviewed by 2 · Jul 18, 2026

Open the Dextromethorphan HBr, Phenylephrine HCl interaction page

How much people look this up

Where Beta-methylphenethylamine (bmpea) and Dextromethorphan HBr, Phenylephrine HCl 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 Beta-methylphenethylamine (bmpea)
Steady interest

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

29 days ago today
Medication Dextromethorphan HBr, Phenylephrine HCl
Steady interest

#1,716 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 Beta-methylphenethylamine (bmpea)

What is Beta-methylphenethylamine (bmpea)?

  • Weight loss
  • Pre-workout energy
  • Athletic performance
  • Appetite suppression
  • Mental focus

Beta-methylphenethylamine (BMPEA) is a synthetic stimulant chemically similar to amphetamine that has been found in some weight-loss and sports supplements, often without being clearly listed on the label. It is not an approved or well-studied dietary ingredient, and regulators have warned that it may carry real cardiovascular risks. Because of safety concerns and the lack of human research, it is best avoided.

Read the full Beta-methylphenethylamine (bmpea) monograph & all interactions
Keep checking

Other Drugs & Beta-methylphenethylamine (bmpea)

Browse every other medication we’ve checked against Beta-methylphenethylamine (bmpea) — both the ones with a known interaction and the ones without. Select any drug for the full detail.

0Major
812Moderate
0Minor
2,017No known interaction
812 Moderate 2,017 No interaction
Moderate

812 interactions

Showing 60 of 812 moderate interactions — see all 812 on the Beta-methylphenethylamine (bmpea) page.

No interaction 2,017 drugs checked — show the list

We also checked Beta-methylphenethylamine (bmpea) against these medications and found no known interaction in our sources. Open any page to confirm.

Showing the 60 most looked-up of 2,017 medications checked with no known interaction — see the full Beta-methylphenethylamine (bmpea) list.

See the full Beta-methylphenethylamine (bmpea) interactions page
See every supplement checked against Dextromethorphan HBr, Phenylephrine HCl, 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
Beta-methylphenethylamine (bmpea) monograph › Uses, safety, and every drug interaction in one place Dextromethorphan HBr, Phenylephrine HCl supplement interactions › Every supplement checked against Dextromethorphan HBr, Phenylephrine HCl, 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 Beta-methylphenethylamine (bmpea) and Dextromethorphan HBr, Phenylephrine HCl Together: Common Questions

Can you take Beta-methylphenethylamine (bmpea) with Dextromethorphan HBr, Phenylephrine HCl?
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 3 interactions listed for Beta-methylphenethylamine (bmpea) and Dextromethorphan HBr, Phenylephrine HCl?
Dextromethorphan HBr, Phenylephrine HCl belongs to more than one drug category, and Beta-methylphenethylamine (bmpea) 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 Beta-methylphenethylamine (bmpea) and Dextromethorphan HBr, Phenylephrine HCl 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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