Drug & supplement interaction

1,3-dmba + Chlorpheniramine, Phenylephrine

Chlorpheniramine, Phenylephrine brand names: Histatab Plus, Ed A Hist, Rynatan, Dallergy JR.

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

1,3-dmba has a moderate interaction with Chlorpheniramine, Phenylephrine. Theoretically, combining 1,3-DMBA with other stimulant drugs might increase the risk of cardiovascular toxicity.

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

1,3-dmba and Chlorpheniramine, Phenylephrine

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

Moderate

STIMULANT DRUGS

Why this applies to Chlorpheniramine, Phenylephrine

Chlorpheniramine, Phenylephrine falls under STIMULANT DRUGS — the group 1,3-dmba interacts with.

Theoretically, combining 1,3-DMBA with other stimulant drugs might increase the risk of cardiovascular toxicity.
Animal research shows that 1,3-DMBA has stimulant effects, such as increasing blood pressure and heart rate.
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 know about this combo. The phenylephrine in your cold or allergy product is itself a decongestant that works by tightening blood vessels, which can nudge up your blood pressure and heart rate. 1,3-DMBA is an unapproved stimulant that does much the same thing. Stack two vessel-tightening stimulants together and the worry is they add up, possibly pushing blood pressure higher, causing a racing or pounding heartbeat, jitteriness, headache, or in rare cases more serious heart strain.

To be fair, this caution comes mainly from animal and lab data, so it's more theoretical than proven in people. Still, I'd steer clear of 1,3-DMBA entirely since the FDA considers it adulterated. Please check with your pharmacist or doctor before mixing these.

Contact Dr. Brian directly if you have additional questions on this interaction
References
  1. SWANSON EE, CHEN KK. Comparison of pressor action of alicyclic derivatives of aliphatic amines. J Pharmacol Exp Ther. 1948 Aug;93(4):423-9.

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 171 moderate, 149 minor known drug interactions in our database — the Chlorpheniramine, Phenylephrine one above is one of them. If you take anything else, check it against the full list below.

Moderate 171 Minor 149 No known interaction 2,510 (incl. Chlorpheniramine, Phenylephrine)
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 Chlorpheniramine, Phenylephrine

This page covers 1,3-dmba only. If you take other supplements — a multivitamin, a sleep aid, something for joints — the Chlorpheniramine, Phenylephrine page lists 229 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), Henbane (major) and Lithium (major).

By severity: 10 major · 175 moderate · 44 minor.

From our pharmacist’s overview on the Chlorpheniramine, Phenylephrine page

“A medicine that stimulates the heart and dries the body doesn't leave much room for supplements pulling the same way, and that describes chlorpheniramine, phenylephrine (Histatab Plus, Ed A Hist, Rynatan) well. Dozens of stimulant herbs, everyday caffeine sources among them, add to the decongestant's strain on blood pressure and heart…”

Reviewed by 2 · Jul 18, 2026

Open the Chlorpheniramine, Phenylephrine interaction page

How much people look this up

Where 1,3-dmba and Chlorpheniramine, 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 1,3-dmba
Steady interest

#1,035 of 1,452 supplements looked up here in the last 7 days

29 days ago today
Medication Chlorpheniramine, Phenylephrine
Steady interest

#1,751 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
171Moderate
149Minor
2,509No known interaction
171 Moderate 149 Minor 2,509 No interaction
Moderate

171 interactions

Showing 60 of 171 moderate interactions — see all 171 on the 1,3-dmba page.

Minor

149 interactions

Showing 60 of 149 minor interactions — see all 149 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 Chlorpheniramine, 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
1,3-dmba monograph › Uses, safety, and every drug interaction in one place Chlorpheniramine, Phenylephrine supplement interactions › Every supplement checked against Chlorpheniramine, 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 1,3-dmba and Chlorpheniramine, Phenylephrine Together: Common Questions

Can you take 1,3-dmba with Chlorpheniramine, 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.
How serious is the 1,3-dmba and Chlorpheniramine, 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.