Drug & supplement interaction

1,3-dmba + Dextromethorphan, Guaifenesin

Dextromethorphan, Guaifenesin brand names: Sudal DM, Touro DM, Queltuss, Fenesin DM, Monafed DM, and others.

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

1,3-dmba has a minor interaction with Dextromethorphan, Guaifenesin. Theoretically, 1,3-DMBA might modestly increase the levels of CYP2D6 substrates.

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

1,3-dmba and Dextromethorphan, Guaifenesin

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

Minor

CYTOCHROME P450 2D6 (CYP2D6) SUBSTRATES

Why this applies to Dextromethorphan, Guaifenesin

Dextromethorphan, Guaifenesin falls under CYTOCHROME P450 2D6 (CYP2D6) SUBSTRATES — the group 1,3-dmba interacts with.

Theoretically, 1,3-DMBA might modestly increase the levels of CYP2D6 substrates.
In vitro research shows that 1,3-DMBA weakly inhibits CYP2D6 enzymes.
Severity Minor 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 cough and chest products like Sudal DM or Fenesin DM. The cough suppressor in them, dextromethorphan, is cleared from your body by a liver enzyme called CYP2D6. Lab tests suggest 1,3-DMBA may weakly slow that enzyme down, which could let dextromethorphan build up a little. In plain terms, that might mean a bit more drowsiness, dizziness, or a foggy, off feeling. The guaifenesin part isn't really affected.

Honestly, this is theoretical and only seen in test-tube studies, so I wouldn't lose sleep over it. My bigger concern is the 1,3-DMBA itself, which is a banned, unsafe stimulant I'd steer clear of. Please check with your pharmacist or doctor before mixing 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

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

1,3-dmba Also Interacts With Other Medications

1,3-dmba has 172 moderate, 148 minor known drug interactions in our database — the Dextromethorphan, Guaifenesin one above is one of them. If you take anything else, check it against the full list below.

Moderate 172 Minor 148 No known interaction 2,510 (incl. Dextromethorphan, Guaifenesin)
Taking anything else?

Check Another of Your Medications Against 1,3-dmba

Covers the 2,830 medications we’ve checked against 1,3-dmba. Pick one to open its full report.

Everything else you take

See Every Supplement That Interacts With Dextromethorphan, Guaifenesin

This page covers 1,3-dmba only. If you take other supplements — a multivitamin, a sleep aid, something for joints — the Dextromethorphan, Guaifenesin page lists 171 supplements it has a documented interaction with, worst first, each one explained.

The most serious there right now: Activated Charcoal (major), Grapefruit (major), Lithium (major), St. John's Wort (major) and 1,3-dmaa (moderate).

By severity: 4 major · 125 moderate · 42 minor.

From our pharmacist’s overview on the Dextromethorphan, Guaifenesin page

“Dextromethorphan with guaifenesin (Sudal DM, Touro DM, Queltuss, and others) sounds too ordinary a cough medicine to tangle badly with supplements, yet 4 of the 171 ingredients on this list rate major and belong at the top of your reading. Grapefruit and St.”

Reviewed by 2 · Jul 18, 2026

Open the Dextromethorphan, Guaifenesin interaction page

How much people look this up

Where 1,3-dmba and Dextromethorphan, Guaifenesin 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 1,3-dmba
Steady interest

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

29 days ago today
Medication Dextromethorphan, Guaifenesin
Steady interest

#1,539 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 1,3-dmba

What is 1,3-dmba?

  • Athletic and workout performance
  • Energy and stimulation
  • Weight loss and fat burning
  • Appetite suppression
  • Focus and concentration

1,3-DMBA is a synthetic stimulant chemically similar to the banned stimulant DMAA, and it is not a proven or safe dietary ingredient. The U.S. FDA considers supplements containing it adulterated, and it is banned in sports. Because of serious heart and stroke risks, it is best to avoid products that contain it.

Read the full 1,3-dmba monograph & all interactions
Keep checking

Other Drugs & 1,3-dmba

Browse every other medication we’ve checked against 1,3-dmba — both the ones with a known interaction and the ones without. Select any drug for the full detail.

0Major
172Moderate
148Minor
2,509No known interaction
172 Moderate 148 Minor 2,509 No interaction
Moderate

172 interactions

Showing 60 of 172 moderate interactions — see all 172 on the 1,3-dmba page.

Minor

148 interactions

Showing 60 of 148 minor interactions — see all 148 on the 1,3-dmba page.

No interaction 2,509 drugs checked — show the list

We also checked 1,3-dmba against these medications and found no known interaction in our sources. Open any page to confirm.

Showing the 60 most looked-up of 2,509 medications checked with no known interaction — see the full 1,3-dmba list.

See the full 1,3-dmba interactions page
See every supplement checked against Dextromethorphan, Guaifenesin, 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
1,3-dmba monograph › Uses, safety, and every drug interaction in one place Dextromethorphan, Guaifenesin supplement interactions › Every supplement checked against Dextromethorphan, Guaifenesin, 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 1,3-dmba and Dextromethorphan, Guaifenesin Together: Common Questions

Can you take 1,3-dmba with Dextromethorphan, Guaifenesin?
There is only a minor interaction, which is usually not serious. Read the full details on this page and confirm with your pharmacist before combining them.
How serious is the 1,3-dmba and Dextromethorphan, Guaifenesin interaction?
We rate it Minor. This interaction is generally not clinically significant, but it remains worth noting and discussing with your pharmacist.

Written and reviewed by the HelloPharmacist editorial staff. Our editorial policy

Still Have a Question About Dextromethorphan, Guaifenesin and 1,3-dmba?

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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.