Drug & supplement interaction

Deanol + Diphenhydramine

Diphenhydramine brand names: Benadryl, Dormin, Allerdryl, Valdrene, Sleep-Ettes D, and others.

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

Deanol has a minor interaction with Diphenhydramine. Theoretically, deanol might decrease the effectiveness of anticholinergic drugs.

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

Deanol and Diphenhydramine

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

Minor

ANTICHOLINERGIC DRUGS

Why this applies to Diphenhydramine

Diphenhydramine falls under ANTICHOLINERGIC DRUGS — the group Deanol interacts with.

Theoretically, deanol might decrease the effectiveness of anticholinergic drugs.
Deanol is thought to increase acetylcholine levels.
Severity Minor Likelihood Unlikely Evidence D

Interaction has been demonstrated in animal or in lab research but has been shown not to occur in humans..

Dr. Brian Staiger, PharmD, BCPS
Dr. Brian Staiger explains PharmD, Clinical Pharmacist

Here's the basic idea with these two. Diphenhydramine (Benadryl) works by blocking acetylcholine, a chemical messenger in your body. Deanol is marketed on the theory that it does the opposite and nudges acetylcholine levels up. So in principle, they could work against each other, and the deanol might slightly blunt how well the Benadryl does its job, whether you're taking it for allergies, sleep, or motion sickness.

I want to be honest, though: this is a theoretical concern based on how the two work on paper, not something well documented in real people. It's rated minor and unlikely, and it's far from certain deanol meaningfully raises brain acetylcholine in humans. Still, if you notice your Benadryl isn't working as well, mention it to your pharmacist or doctor.

Contact Dr. Brian directly if you have additional questions on this interaction
References
  1. Re O. 2-Dimethylaminoethanol (deanol): a brief review of its clinical efficacy and postulated mechanism of action. Curr Ther Res Clin Exp 1974;16:1238-42.

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

Deanol Also Interacts With Other Medications

Deanol has 218 minor known drug interactions in our database — the Diphenhydramine one above is one of them. If you take anything else, check it against the full list below.

Minor 218 No known interaction 2,612 (incl. Diphenhydramine)
Taking anything else?

Check Another of Your Medications Against Deanol

Covers the 2,830 medications we’ve checked against Deanol. Pick one to open its full report.

From our Q&A

Questions About Deanol or Diphenhydramine

These are real questions from readers, answered by the pharmacists at HelloPharmacist — written by a person, not generated from a database. Each one covers Deanol or Diphenhydramine, 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 Diphenhydramine

This page covers Deanol only. If you take other supplements — a multivitamin, a sleep aid, something for joints — the Diphenhydramine page lists 147 supplements it has a documented interaction with, worst first, each one explained.

The most serious there right now: 1,4-butanediol (major), Activated Charcoal (major), Beer (major), Gamma-hydroxybutyrate (ghb) (major) and Henbane (major).

By severity: 9 major · 119 moderate · 19 minor.

From our pharmacist’s overview on the Diphenhydramine page

“Diphenhydramine (Benadryl, Simply Sleep) is sedating by design, and most of the 147 supplements and herbal ingredients on this list lean into that. Seventy-eight are sedating substances themselves, alcohol and kava the standouts, and stacking them can slow breathing and reflexes well beyond ordinary drowsiness.”

Reviewed by 2 · Jul 18, 2026

Open the Diphenhydramine interaction page

One more smart check

Taking Deanol as Part of a Dietary Supplement Product? Check It for Interactions

We hold 1,143 real supplement products containing Deanol, each one broken down to its full ingredient list — and combination products often carry several ingredients besides Deanol. Your product may carry other ingredients that interact with Diphenhydramine too, on top of Deanol — and those would not show on this page. Find your product and we’ll check every ingredient on its label:

How much people look this up

Where Deanol and Diphenhydramine 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 Deanol
Top 25%

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

29 days ago today
Medication Diphenhydramine
Top half

#753 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 Deanol

What is Deanol?

Deanol
  • Memory and focus
  • Mood and mental clarity
  • ADHD-type symptoms
  • Skin firmness (topical)
  • General brain health

Deanol (DMAE) is a compound related to choline that is marketed for memory, focus, and mood, but solid human evidence for most of these uses is limited or mixed. It can cause side effects in some people, and it should be avoided in pregnancy and breastfeeding because its safety is not established. Talk to your pharmacist or doctor before trying it.

Read the full Deanol monograph & all interactions
Medication

About Diphenhydramine

What Is Diphenhydramine Used For?

Brand names: Benadryl, Dormin, Allerdryl, Valdrene, Sleep-Ettes D, Simply Sleep, Sominex, Diphenhydramine, Compoz, Sleep Aid, Benadryl cream, Benadryl spray, Dermamycin cream, Ziradryl, Nytol

Diphenhydramine temporarily relieves symptoms of hay fever, other upper respiratory allergies, and the common cold — including runny nose, sneezing, itchy or watery eyes, and itching of the nose or throat.

After Bite Xtra gel is formulated for topical use and is approved to temporarily relieve pain and itching from minor burns, minor cuts and scrapes, insect bites, minor skin irritations, and rashes from poison ivy, poison oak, and poison sumac.

See full Diphenhydramine drug information
Keep checking

Other Drugs & Deanol

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

0Major
0Moderate
218Minor
2,611No known interaction
218 Minor 2,611 No interaction
Minor

218 interactions

Showing 60 of 218 minor interactions — see all 218 on the Deanol page.

No interaction 2,611 drugs checked — show the list

We also checked Deanol against these medications and found no known interaction in our sources. Open any page to confirm.

Showing the 60 most looked-up of 2,611 medications checked with no known interaction — see the full Deanol list.

See the full Deanol interactions page
See every supplement checked against Diphenhydramine, 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
Deanol monograph › Uses, safety, and every drug interaction in one place Diphenhydramine supplement interactions › Every supplement checked against Diphenhydramine, ranked by severity Diphenhydramine 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 Deanol and Diphenhydramine Together: Common Questions

Can you take Deanol with Diphenhydramine?
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 Deanol and Diphenhydramine 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 Diphenhydramine and Deanol?

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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.