Drug & supplement interaction

Beta-methylphenethylamine (bmpea) + Dextromethorphan, Guaifenesin, Phenylephrine

Dextromethorphan, Guaifenesin, Phenylephrine brand names: Albatussin Sr, Giltuss.

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

Dextromethorphan, Guaifenesin, Phenylephrine 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, Guaifenesin, Phenylephrine

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, Guaifenesin, Phenylephrine 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, Guaifenesin, Phenylephrine

Dextromethorphan, Guaifenesin, Phenylephrine 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 piece that matters in this combo product: the dextromethorphan (the cough suppressant) is cleared from your body largely by a liver enzyme called CYP2D6. In lab studies, BMPEA appears to block that enzyme. If it does the same thing in people, dextromethorphan could build up and hit you harder than expected, leading to drowsiness, dizziness, confusion, or feeling off-balance. At very high levels it can even cause agitation or hallucinations.

I'll be honest with you: this is a theoretical concern based on test-tube data, not real patient cases. But there's a bigger worry here. BMPEA is an amphetamine-like stimulant, and combining it with the phenylephrine decongestant could push your heart rate and blood pressure up. I'd skip BMPEA entirely and check with your pharmacist.

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, Guaifenesin, Phenylephrine 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 for this combo cough and cold medicine. One of its ingredients, dextromethorphan, is partly broken down by a liver enzyme called CYP3A4. Lab research suggests BMPEA may slow that enzyme down a bit, which could let dextromethorphan build up and lead to more of its effects, like drowsiness, dizziness, or feeling foggy. Just keep in mind this is only a theoretical concern based on test-tube data, not real-world cases.

What worries me more is the overlap in the other direction. BMPEA acts like a stimulant, and your product also contains phenylephrine, a decongestant that raises blood pressure and heart rate. Stacking two stimulant-like ingredients could push your blood pressure or pulse up. Please run this past 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

STIMULANT DRUGS

3 of 3

Dextromethorphan, Guaifenesin, Phenylephrine 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 to watch with this combo cough and cold product: the phenylephrine in it is itself a stimulant-type ingredient (a decongestant) that can nudge up your blood pressure and heart rate. BMPEA is a synthetic compound chemically close to amphetamine, so it can do the same thing. Stacking two stimulant-acting substances together may add up and push your heart harder than either would alone.

In real terms, that could mean a racing or pounding heartbeat, jittery feelings, headache, or a rise in blood pressure. I'll be honest, this concern is theoretical and based on how these substances behave, not on solid human studies. Still, BMPEA isn't an approved ingredient and is best avoided. Please check with your pharmacist or doctor before mixing them.

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, Guaifenesin, Phenylephrine 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, Guaifenesin, Phenylephrine)
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, Guaifenesin, Phenylephrine

This page covers Beta-methylphenethylamine (bmpea) only. If you take other supplements — a multivitamin, a sleep aid, something for joints — the Dextromethorphan, Guaifenesin, Phenylephrine 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, Guaifenesin, Phenylephrine page

“A combination cough medicine like dextromethorphan, guaifenesin, and phenylephrine (Albatussin Sr, Giltuss) deserves real care around supplements, not casual mixing. Of the 197 ingredients with an interaction on file, 8 carry a major rating, and those are the ones to understand first.”

Reviewed by 2 · Jul 18, 2026

Open the Dextromethorphan, Guaifenesin, Phenylephrine interaction page

How much people look this up

Where Beta-methylphenethylamine (bmpea) and 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 Beta-methylphenethylamine (bmpea)
Steady interest

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

29 days ago today
Medication Dextromethorphan, Guaifenesin, Phenylephrine
Top half

#935 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, 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
Beta-methylphenethylamine (bmpea) monograph › Uses, safety, and every drug interaction in one place Dextromethorphan, Guaifenesin, Phenylephrine supplement interactions › Every supplement checked against 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 Beta-methylphenethylamine (bmpea) and Dextromethorphan, Guaifenesin, Phenylephrine Together: Common Questions

Can you take Beta-methylphenethylamine (bmpea) with 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 3 interactions listed for Beta-methylphenethylamine (bmpea) and Dextromethorphan, Guaifenesin, Phenylephrine?
Dextromethorphan, Guaifenesin, Phenylephrine 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, 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.