Drug & supplement interaction

Avens + Clemastine

Clemastine brand name: Tavist Allergy.

No Known Interaction
Medically reviewed by · Updated July 2026 · Pair last verified Sep 20, 2026
The bottom line No known interaction

We found no known interaction between Avens and Clemastine in our sources. Absence of a documented interaction is not the same as proven safety, and does not guarantee one does not exist. Do not start, stop, or change a medication or supplement based on this page; confirm with your pharmacist or doctor first.

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Interaction report

Avens and Clemastine

We checked these two against our interaction database. Here is what we found.

No Known Interaction Found

We did not find a documented interaction between Clemastine and Avens in our sources. This does not guarantee that the combination is completely free of risk — there is often limited research on supplements and herbal products, especially around drug interactions.

Worth understanding: our licensed dataset holds no drug-interaction record for Avens at all — not against Clemastine, and not against any other medication we track. This verdict therefore rests on the absence of any recorded data, not on research that looked at this combination and found nothing. We cannot rule an interaction out.

If you decide to take both, the practical routine is simple: add one new thing at a time and note the date you started it. If the combination is going to disagree with you, it usually shows in the first days to a couple of weeks — and a start date turns “I’ve been feeling off” into something a pharmacist can actually work with. Do not stop a prescribed medicine on your own.

Always talk with your pharmacist or doctor before making changes to your medications or supplements, particularly if you take several medications or have an ongoing health condition.

Avens safety at a glance

Avens overall Use caution Generally used in food-like amounts, but human safety data are very limited.
Pregnancy Possibly Unsafe When used orally because avens seems to have an effect on the menstrual cycle; avoid using. Read the full pregnancy detail
Breastfeeding Avoid No reliable safety data while breastfeeding, so avoid it.

Pregnancy & breastfeeding ratings are from Natural Medicines (Therapeutic Research Center) — the full detail is in the Special populations card below. Safety guidance is general; always confirm with your pharmacist or doctor for your situation.

Still wondering about combining Clemastine and Avens? Ask Dr. Brian Staiger, PharmD, BCPS directly ›
What to actually watch for

What Clemastine’s Own FDA Label Lists

This is not an interaction — none of it involves Avens. These are the most notable effects listed in the ADVERSE REACTIONS section of Clemastine’s own FDA label, for the medication by itself. Knowing the drug’s own list makes it easier to work out the likely cause if something new turns up while you take both. 10 of them are worth acting on rather than waiting out — marked below.

  • Trouble passing urine Worth acting on
  • Wheezing Worth acting on
  • An irregular heartbeat Worth acting on
  • Confusion Worth acting on
  • Seizures Worth acting on
  • A low platelet count Worth acting on
  • Anemia Worth acting on
  • A severe allergic reaction Worth acting on
  • Hives Worth acting on
  • A low white blood cell count Worth acting on

Showing the 10 most notable of 32 label-listed effects — ranked by how unusual each one is across medicines generally, with serious effects weighted up.

From the ADVERSE REACTIONS section of the FDA label for Clemastine. Read the label on DailyMed › Avens’s licensed record lists no adverse effects our clinical vocabulary could match, so there is no Avens side to compare — that is a limit of the record, not a statement that Avens has no side effects.

Special populations

Avens in Pregnancy & Breastfeeding

Pregnancy Possibly Unsafe

When used orally because avens seems to have an effect on the menstrual cycle; avoid using.

DISCLAIMER: This tool is intended for informational purposes only, and should not be interpreted as specific medical advice. Patients should consult with a qualified healthcare provider before making decisions about therapies and/or health conditions.© 2026 Therapeutic Research Center

From our Q&A

Questions About Avens 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 Avens 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 Avens 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 Avens as Part of a Dietary Supplement Product? Check It for Interactions

We hold 8 real supplement products containing Avens, each one broken down to its full ingredient list — and combination products often carry several ingredients besides Avens. Even though Avens itself has no known interaction with Clemastine, another ingredient on your label might. Find your product and we’ll check every ingredient on its label:

How much people look this up

Where Avens 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 Avens
Steady interest

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

29 days ago today
Medication Clemastine
Steady interest

#2,561 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.

Where does our data come from?
  • Source: the Natural Medicines (TRC Healthcare) clinical database — the evidence-graded professional reference for herb & supplement interactions.
  • Citation library: 103,510 references behind our interaction content, 65,311 of them resolved to verified PubMed/DOI sources. See every Avens reference on this page ↓
  • Freshness: we automatically re-check this combination every week — this pair was last verified September 20, 2026. The Avens and Clemastine records this page draws on were last updated July 11, 2026.
  • What “no known interaction” means: no documented interaction in the sources above — not a guarantee of safety. Supplements are studied far less than prescription drugs, so we say exactly what the evidence supports, and nothing more.
Data structure & sourcing designed and verified by .
Supplement

About Avens

What is Avens?

Avens
  • Diarrhea
  • Indigestion and dyspepsia
  • Gas (flatulence)
  • Sore throat and mouth rinses
  • Mild inflammation

Avens is a traditional European herb whose root and leaves are rich in tannins and have long been used as a tea for diarrhea and digestive upset. Solid human research is lacking, so its benefits are unproven. If you choose to try it, use it short-term, follow the product label, and check first with your pharmacist or doctor.

Geum urbanum · Rosaceae · Dried aerial (flowering) parts and roots · Tea (infusion), decoction, dried herb, root powder, tincture

An interaction check asks whether these two react with each other — it does not ask whether Avens is a good idea for someone in your situation. Here is what our Avens record says about it on its own.

Avens: dosing

There is no officially established or standardized dose for Avens. Traditional sources describe steeping a small amount of dried herb in hot water as a tea, or briefly boiling the dried root to make a decoction.Because product strengths vary widely, the safest approach is to follow the directions on the product label and not exceed them.

From our Avens monograph — the full record covers uses, side effects and every documented interaction.

Read the full Avens 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 & Avens

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

0Major
0Moderate
0Minor
2,829No known interaction
2,829 No interaction
No interaction 2,829 drugs checked — show the list

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

Showing the 60 most looked-up of 2,829 medications checked with no known interaction — see the full Avens list.

See the full Avens interactions page
See every supplement checked against Clemastine, ranked by severity
Evidence & sources

Avens References

The 1 references that drive our Avens monograph and interaction data, from the evidence-graded Natural Medicines (TRC Healthcare) database. Citations with a link open the study on PubMed or the publisher’s site.

  1. Newall CA, Anderson LA, Philpson JD. Herbal Medicine: A Guide for Healthcare Professionals. London, UK: The Pharmaceutical Press, 1996.

Medication overviews come from MedlinePlus (NIH); supplement label data from the NIH Dietary Supplement Label Database. Content is written and reviewed by licensed HelloPharmacist pharmacists — see our data sources and editorial standards.

Pharmacist Counseling Corner

Taking Avens and Clemastine Together: Common Questions

Is it safe to take Avens with Clemastine?
We do not list a known interaction between Avens and Clemastine. That does not guarantee the combination is risk-free, so confirm with your pharmacist or doctor — especially if you take other medications or have a health condition.
Does Clemastine interact with any supplements?
Yes. Clemastine has documented interactions with 72 supplements in our database — Avens is not one of them. The Clemastine interaction page linked on this page lists every one, ranked by severity.

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

Where next

Keep Exploring

Avens monograph Uses, safety profile, and every drug interaction in one place Clemastine drug information The full plain-English guide to this medication Clemastine supplement interactions Every supplement checked against Clemastine, 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 References The 1 citations behind this page Ask a pharmacist Free, personal answer from our licensed team

Still Have a Question About Clemastine and Avens?

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.