Drug & supplement interaction

German Chamomile + Cetirizine

Cetirizine brand names: Cetirizine, Zyrtec, Quzyttir.

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

German Chamomile has a moderate interaction with Cetirizine. Theoretically, German chamomile might have additive effects when used with CNS depressants.

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

German Chamomile and Cetirizine

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

Moderate

CNS DEPRESSANTS

Why this applies to Cetirizine

Cetirizine falls under CNS DEPRESSANTS — the group German Chamomile interacts with.

Theoretically, German chamomile might have additive effects when used with CNS depressants.
German chamomile has mild sedative effects. Theoretically, concomitant use with drugs with sedative properties can cause additive effects and side effects.
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 deal with pairing chamomile tea and cetirizine (Zyrtec). Cetirizine is an antihistamine, and even though it's labeled "non-drowsy," it can still make some folks feel a little sleepy or sluggish. Chamomile has its own gentle, calming effect. Put the two together and those drowsy feelings could simply add up, so you might notice more tiredness, a foggy head, or feeling more relaxed than usual.

I want to be honest about the strength here: this is a theoretical concern based mostly on lab work, not strong human studies, and a normal cup of chamomile tea is pretty mild. There's no enzyme problem here, cetirizine isn't a prodrug, so it's really just two calming things stacking. Still, if you notice extra drowsiness or plan to drive, check in with your pharmacist or doctor.

Contact Dr. Brian directly if you have additional questions on this interaction
References
  1. Viola H, Wasowski C, Levi de Stein M, et al. Apigenin, a component of Matricaria recutita flowers, is a central benzodiazepine receptors-ligand with anxiolytic effects. Planta Med 1995;61:213-6.
  2. Avallone R, Zanoli P, Puia G, et al. Pharmacological profile of apigenin, a flavonoid isolated from Matricaria chamomilla. Biochem Pharmacol 2000;59:1387-94. PubMed
  3. Loggia RD, Traversa U, Scarcia V, et al. Depressive effects of Chamomilla recutita (L.) Rausch, tubular flowers, on central nervous system in mice. Pharmacol Res Commun 1982;14(2):153-162. 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

German Chamomile Also Interacts With Other Medications

German Chamomile has 924 moderate, 35 minor known drug interactions in our database — the Cetirizine one above is one of them. If you take anything else, check it against the full list below.

Moderate 924 Minor 35 No known interaction 1,871 (incl. Cetirizine)
Taking anything else?

Check Another of Your Medications Against German Chamomile

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

From our Q&A

Questions About German Chamomile or Cetirizine

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

This page covers German Chamomile only. If you take other supplements — a multivitamin, a sleep aid, something for joints — the Cetirizine page lists 100 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 Kava (major).

By severity: 7 major · 78 moderate · 15 minor.

From our pharmacist’s overview on the Cetirizine page

“Cetirizine (Zyrtec) treats allergies, but even this newer antihistamine can make some people drowsy, and that weak spot is where most of its 100 documented supplement interactions land. Seventy-eight of the ingredients on this page add their own sedative pull on top of the drug's, and 7 of the 100 rate major, so treat this list with re…”

Reviewed by 2 · Jul 18, 2026

Open the Cetirizine interaction page

One more smart check

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

We hold 782 real supplement products containing German Chamomile, each one broken down to its full ingredient list — and combination products often carry several ingredients besides German Chamomile. Your product may carry other ingredients that interact with Cetirizine too, on top of German Chamomile — 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 German Chamomile and Cetirizine 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 German Chamomile
Top 25%

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

29 days ago today
Medication Cetirizine
Top 25%

#402 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 German Chamomile

What is German Chamomile?

German Chamomile
  • Anxiety and stress
  • Sleep and relaxation
  • Digestive upset
  • Skin irritation and inflammation
  • Mouth sores and gum irritation

German chamomile is a widely used herbal remedy taken mainly as a tea for calming, sleep, and digestive complaints. Early research suggests possible benefits for mild anxiety and some skin or digestive issues, but the evidence is limited and most uses are based on tradition rather than strong proof. It is generally well tolerated, but people allergic to ragweed or related plants and those who are pregnant should be cautious.

Read the full German Chamomile monograph & all interactions
Medication

About Cetirizine Injection

What Is Cetirizine Injection Used For?

Brand names: Cetirizine, Zyrtec, Quzyttir

Quzyttir (cetirizine injection) is approved to treat acute urticaria — a sudden outbreak of hives — in adults and in children 6 months of age and older. It is given by intravenous (IV) injection in a medically supervised setting.

Quzyttir is not recommended for children under 6 years of age who have impaired kidney or liver function.

See full Cetirizine Injection drug information
Keep checking

Other Drugs & German Chamomile

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

0Major
924Moderate
35Minor
1,870No known interaction
924 Moderate 35 Minor 1,870 No interaction
Moderate

924 interactions

Showing 60 of 924 moderate interactions — see all 924 on the German Chamomile page.

Minor

35 interactions

No interaction 1,870 drugs checked — show the list

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

Showing the 60 most looked-up of 1,870 medications checked with no known interaction — see the full German Chamomile list.

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

Can you take German Chamomile with Cetirizine?
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 German Chamomile and Cetirizine 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

Still Have a Question About Cetirizine and German Chamomile?

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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.