Drug & supplement interaction

Beta-methylphenethylamine (bmpea) + Thioridazine

Thioridazine brand name: Mellaril.

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

Beta-methylphenethylamine (bmpea) has a moderate interaction with Thioridazine. Theoretically, BMPEA might increase the levels and clinical effects of CYP2D6 substrates.

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

Beta-methylphenethylamine (bmpea) and Thioridazine

Here is the interaction we found between these two, with the evidence behind it.

Moderate

CYTOCHROME P450 2D6 (CYP2D6) SUBSTRATES

Why this applies to Thioridazine

Thioridazine 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 concern with this pairing. Your body relies on a liver enzyme called CYP2D6 to clear thioridazine out of your system. Lab studies suggest BMPEA can strongly block that same enzyme. If it does, thioridazine could build up to higher levels than intended, which means more drug effect and more side effects.

With thioridazine that matters more than usual, because this drug is well known for affecting the heart's rhythm (a change called QT prolongation). Higher levels could also bring on drowsiness, dizziness, low blood pressure, or a racing heartbeat, and the stimulant nature of BMPEA adds its own strain on your heart. This is based on lab data, not human studies, but I'd treat it cautiously and talk with your doctor or pharmacist before combining the two.

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

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 Thioridazine one above is one of them. If you take anything else, check it against the full list below.

Moderate 812 No known interaction 2,018 (incl. Thioridazine)
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.

From our Q&A

Questions About Beta-methylphenethylamine (bmpea) or Thioridazine

These are real questions from readers, answered by the pharmacists at HelloPharmacist — written by a person, not generated from a database. Each one covers Beta-methylphenethylamine (bmpea) or Thioridazine, not necessarily both, but if one is close to what you were about to ask it will usually go further than a database entry can:

Not quite your question? Ask our pharmacists directly — it is free, there is no account required, and answers usually come back within 24 hours.

Everything else you take

See Every Supplement That Interacts With Thioridazine

This page covers Beta-methylphenethylamine (bmpea) only. If you take other supplements — a multivitamin, a sleep aid, something for joints — the Thioridazine page lists 168 supplements it has a documented interaction with, worst first, each one explained.

The most serious there right now: Activated Charcoal (major), American Hellebore (major), Arsenic (major), Cesium (major) and Ephedra (major).

By severity: 11 major · 125 moderate · 32 minor.

From our pharmacist’s overview on the Thioridazine page

“Thioridazine (Mellaril) is an older antipsychotic already known for disturbing the heart's rhythm, and the supplements that worry me most here do the same thing, stretching the QT interval further. Grapefruit in large amounts sits in that group, alongside ephedra and several other major-rated entries.”

Reviewed by 2 · Jul 18, 2026

Open the Thioridazine interaction page

How much people look this up

Where Beta-methylphenethylamine (bmpea) and Thioridazine 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)
Top half

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

29 days ago today
Medication Thioridazine
Top half

#1,163 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
Medication

About Thioridazine

What Is Thioridazine Used For?

Brand name: Mellaril

Thioridazine Hydrochloride tablets are used for the management of schizophrenia — but only in patients who have already tried at least two other antipsychotic medications without adequate results, either because those drugs didn't work well enough or caused intolerable side effects.

Because thioridazine carries serious heart-rhythm risks, it is considered a last-resort option for schizophrenia, not a first-line treatment. It is not approved for dementia-related psychosis or any other psychiatric condition.

See full Thioridazine drug information
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 Thioridazine, 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 Thioridazine supplement interactions › Every supplement checked against Thioridazine, ranked by severity Thioridazine drug information › The full plain-English guide to this medication 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 Thioridazine Together: Common Questions

Can you take Beta-methylphenethylamine (bmpea) with Thioridazine?
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.
How serious is the Beta-methylphenethylamine (bmpea) and Thioridazine 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.