Drug & supplement interaction

Deanol + Clemastine

Clemastine brand name: Tavist Allergy.

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

Deanol has a minor interaction with Clemastine. 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 Clemastine

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

Minor

ANTICHOLINERGIC DRUGS

Why this applies to Clemastine

Clemastine 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 simple version. Clemastine works by blocking a body chemical called acetylcholine (that's part of how it dries up a runny nose and calms itchy, watery eyes). Deanol, on the other hand, is thought to do the opposite and nudge acetylcholine levels up. So in theory, the two could work against each other, and you might get a little less allergy relief from your Tavist.

I want to keep this in perspective, though. This is a theoretical concern based on how these substances behave, not something we see reported often in real life. It's rated minor and unlikely. If you take both and notice your allergy symptoms aren't as controlled, just mention it to your pharmacist or doctor before changing anything.

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 Clemastine 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. Clemastine)
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 Clemastine

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 Clemastine, 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 Clemastine

This page covers Deanol only. If you take other supplements — a multivitamin, a sleep aid, something for joints — the Clemastine page lists 72 supplements it has a documented interaction with, worst first, each one explained.

The most serious there right now: Activated Charcoal (major), Henbane (major), Scopolia (major), Alfalfa (moderate) and Angel's Trumpet (moderate).

By severity: 3 major · 57 moderate · 12 minor.

From our pharmacist’s overview on the Clemastine page

“Clemastine (Tavist Allergy) is an older, sedating antihistamine that already dries the mouth, blurs vision, and slows the gut, and that is exactly why this list earns real caution rather than a quick skim. Thirty of the 72 supplements on file pile the same drying, sedating anticholinergic load on top, and two of the three major-rated e…”

Reviewed by 2 · Jul 18, 2026

Open the Clemastine 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 Clemastine 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 Clemastine 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 Clemastine
Top half

#1,384 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 Clemastine

What Is Clemastine Used For?

Brand name: Tavist Allergy

Clemastine treats symptoms of allergic rhinitis (hay fever and similar nasal allergies) — including sneezing, runny nose, itching, and watery eyes. The oral solution (Clemastine Fumarate syrup) is indicated for adults and children aged 6 through 12 years. The tablets (Clemastine Fumarate and Clemsza) are indicated for adults.

Clemastine also treats mild, uncomplicated allergic skin reactions — specifically urticaria (hives) and angioedema (swelling under the skin) — at the appropriate dosage level, in both the oral solution and tablet forms.

See full Clemastine 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 Clemastine, 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 Clemastine supplement interactions › Every supplement checked against Clemastine, ranked by severity Clemastine 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 Clemastine Together: Common Questions

Can you take Deanol with Clemastine?
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 Clemastine 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 Clemastine and Deanol?

Our pharmacists answer your medication & supplement questions — free.

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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.