Drug & supplement interaction

Beta-methylphenethylamine (bmpea) + Aspirin, Caffeine

Aspirin, Caffeine brand name: Anacin.

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

Aspirin, Caffeine falls into 2 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 CYP3A4 substrates.

Read the full interaction report
SeverityModerate
LikelihoodPossible
Interactions2
EvidenceD
What do Severity, Likelihood & Evidence mean?
Know someone taking this? Share
Facebook Post Reddit Email
On this page
Interaction report

Beta-methylphenethylamine (bmpea) and Aspirin, Caffeine

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

Why Are There 2 Interactions?

Beta-methylphenethylamine (bmpea) interacts with whole categories of medication. Aspirin, Caffeine falls into 2 of those categories, so it can interact with Beta-methylphenethylamine (bmpea) 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 Aspirin, Caffeine

Aspirin, Caffeine falls under CYTOCHROME P450 3A4 (CYP3A4) SUBSTRATES — the group Beta-methylphenethylamine (bmpea) interacts with.

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 thing to keep in mind with a product like Anacin, which combines aspirin and caffeine. The caffeine part is partly cleared by a liver enzyme called CYP3A4. In a test tube, BMPEA slowed that enzyme down by about a third. In theory, that could let caffeine linger a bit longer, nudging up the jittery side of things like a racing heart, restlessness, trouble sleeping, or higher blood pressure.

Honestly, my bigger worry isn't the lab math. It's that BMPEA itself is an amphetamine-like stimulant, so stacking it with caffeine piles stimulant on stimulant. This interaction is only theoretical, but BMPEA is one I'd steer clear of regardless. Please check with your pharmacist or doctor 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

2 of 2

Aspirin, Caffeine 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 keep in mind: the product you asked about (Anacin) combines aspirin with caffeine, and caffeine is itself a mild stimulant. BMPEA is a synthetic compound built much like amphetamine, so it can also rev up your system. When you stack two stimulants together, their effects can add up.

In plain terms, pairing BMPEA with the caffeine in this product could push your heart rate up and raise your blood pressure more than either would alone. You might feel jittery, have a racing or pounding heartbeat, or feel anxious or shaky. I'll be honest, this concern is theoretical and based on how these stimulants behave, not on solid human studies. Still, since BMPEA carries real heart risks and isn't a well-vetted ingredient, I'd avoid it and check with your pharmacist first.

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 Aspirin, Caffeine 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. Aspirin, Caffeine)
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 Aspirin, Caffeine

This page covers Beta-methylphenethylamine (bmpea) only. If you take other supplements — a multivitamin, a sleep aid, something for joints — the Aspirin, Caffeine page lists 347 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), Danshen (major) and Ephedra (major).

By severity: 13 major · 285 moderate · 49 minor.

From our pharmacist’s overview on the Aspirin, Caffeine page

“Anacin combines aspirin with caffeine, so supplements can hit it from two directions, and a few of the 347 on this list deserve real respect. The biggest group, over 200 ingredients, can raise bleeding risk on top of aspirin's blood-thinning effect; beer and wine carry major ratings because alcohol plus an aspirin-type drug makes stoma…”

Reviewed by 2 · Jul 18, 2026

Open the Aspirin, Caffeine interaction page

How much people look this up

Where Beta-methylphenethylamine (bmpea) and Aspirin, Caffeine 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

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

29 days ago today
Medication Aspirin, Caffeine
Top half

#782 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 Aspirin, Caffeine, 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 Aspirin, Caffeine supplement interactions › Every supplement checked against Aspirin, Caffeine, 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 Aspirin, Caffeine Together: Common Questions

Can you take Beta-methylphenethylamine (bmpea) with Aspirin, Caffeine?
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 Beta-methylphenethylamine (bmpea) and Aspirin, Caffeine?
Aspirin, Caffeine 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 Aspirin, Caffeine 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

Still Have a Question About Aspirin, Caffeine and Beta-methylphenethylamine (bmpea)?

Our pharmacists answer your medication & supplement questions — free.

Ask a pharmacist

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.