Drug & supplement interaction

German Chamomile + Oestrogen

Oestrogen brand name: Oestrogen.

Moderate Interaction
The bottom line Moderate

Oestrogen falls into 3 drug categories that German Chamomile can interact with; the most serious is rated moderate. Theoretically, German chamomile might inhibit CYP3A4 and increase levels of drugs metabolized by these enzymes.

Read the full interaction report
SeverityModerate
LikelihoodPossible
Interactions3
EvidenceD
What do Severity, Likelihood & Evidence mean?
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Interaction report

German Chamomile and Oestrogen

These two interact in 3 distinct ways. Each one is explained separately below.

Why Are There 3 Interactions?

German Chamomile interacts with whole categories of medication. Oestrogen falls into 3 of those categories, so it can interact with German Chamomile in 3 different ways. We’ve listed each one below — your overall risk is driven by the most serious of them (Moderate).

Moderate

CYTOCHROME P450 3A4 (CYP3A4) SUBSTRATES

1 of 3

Why this applies to Oestrogen

Oestrogen falls under CYTOCHROME P450 3A4 (CYP3A4) SUBSTRATES — the group German Chamomile interacts with.

Theoretically, German chamomile might inhibit CYP3A4 and increase levels of drugs metabolized by these enzymes.
In vitro evidence shows that German chamomile might inhibit CYP3A4. So far, this interaction has not been reported in humans. However, there might be an increase in the levels of drugs metabolized by CYP3A4 in patients taking German chamomile.
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 gist: your body uses an enzyme called CYP3A4 to help break down and clear estrogen. Lab studies (in test tubes, not people yet) suggest German chamomile may slow that enzyme down a bit. If that happened in real life, estrogen could clear a little more slowly and build up, which might mean stronger estrogen effects like breast tenderness, bloating, nausea, headaches, or spotting.

I want to keep this in perspective, though. This is only theoretical right now, and it has never actually been reported in people. An occasional cup of chamomile tea is very unlikely to cause trouble. Concentrated chamomile supplements are more of a question mark. If you use chamomile regularly, just mention it to your pharmacist or doctor so they can keep an eye on things.

References
  1. Budzinski JW, Foster BC, Vandenhoek S, Arnason JT. An in vitro evaluation of human cytochrome P450 3A4 inhibition by selected commercial herbal extracts and tinctures. Phytomedicine 2000;7:273-82. PubMed
  2. Ganzera M, Schneider P, Stuppner H. Inhibitory effects of the essential oil of chamomile (Matricaria recutita L.) and its major constituents on human cytochrome P450 enzymes. Life Sci 2006;78(8):856-861. PubMed
Moderate

ESTROGENS

2 of 3

Oestrogen also falls under ESTROGENS.

Theoretically, large amounts of German chamomile might reduce the effectiveness of estrogens.
In vitro, German chamomile has demonstrated antiestrogenic activity. Theoretically, large amounts of German chamomile might interfere with hormone replacement therapy through competition for estrogen receptors.
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 gist with chamomile and your estrogen. In lab dishes, compounds in German chamomile (like apigenin) seem to compete with estrogen at its receptors, which could in theory dampen how well your estrogen works. If that played out in the body, you might notice your therapy feeling less effective, think more hot flashes, night sweats, or other menopausal symptoms creeping back.

The important part: this is only seen in test-tube studies, not in real people, so I wouldn't lose sleep over it. A cup or two of chamomile tea is very unlikely to matter. The concern, if any, would be with large, concentrated supplement doses. If you take chamomile regularly, just mention it to your pharmacist or doctor so they can keep an eye on things.

References
  1. Kassi E, Papoutsi Z, Fokialakis N, et al. Greek plant extracts exhibit selective estrogen receptor modulator (SERM)-like properties. J Agric Food Chem 2004;52:6956-61. PubMed
Minor

CYTOCHROME P450 1A2 (CYP1A2) SUBSTRATES

3 of 3

Oestrogen also falls under CYTOCHROME P450 1A2 (CYP1A2) SUBSTRATES.

Theoretically, German chamomile might inhibit CYP1A2 and increase levels of drugs metabolized by these enzymes.
In vitro and animal research shows that German chamomile might inhibit CYP1A2. So far, this interaction has not been reported in humans. However, there might be an increase in the levels of drugs metabolized by CYP1A2 in patients taking German chamomile.
Severity Minor 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 gist: lab and animal studies hint that German chamomile may slow down an enzyme called CYP1A2, which is one of the pathways your body uses to clear estrogen. If that enzyme works more slowly, a little more estrogen could hang around in your system. In theory that might nudge up estrogen-type effects, such as breast tenderness, bloating, nausea, or headaches.

The important part is how weak this evidence is. This has only been seen in test tubes and animals, never confirmed in people, and it's rated a minor interaction. An occasional cup of chamomile tea is very unlikely to cause trouble. If you use concentrated chamomile supplements regularly, just mention it to your pharmacist or doctor so they can keep an eye on things.

References
  1. Maliakal PP, Wanwimolruk S. Effect of herbal teas on hepatic drug metabolizing enzymes in rats. J Pharm Pharmacol 2001;53:1323-9. PubMed
  2. Ganzera M, Schneider P, Stuppner H. Inhibitory effects of the essential oil of chamomile (Matricaria recutita L.) and its major constituents on human cytochrome P450 enzymes. Life Sci 2006;78(8):856-861. 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 Oestrogen one above is among them. If you take anything else, check it against the full list below.

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.

Everything else you take

See Every Supplement That Interacts With Oestrogen

This page covers German Chamomile only. If you take other supplements — a multivitamin, a sleep aid, something for joints — the Oestrogen page lists 211 supplements it has a documented interaction with, worst first, each one explained.

The most serious there right now: Activated Charcoal (major), Grapefruit (major), St. John's Wort (major), Acacia Rigidula (moderate) and Adrafinil (moderate).

By severity: 3 major · 170 moderate · 38 minor.

From our pharmacist’s overview on the Oestrogen page

“Anyone taking oestrogen should read this page with real care, because the most serious entries can quietly push hormone levels up or wipe them out. Grapefruit blocks the liver enzyme that clears estrogen, raising levels and the risk of side effects, while St.”

Reviewed by 2 · Jul 18, 2026

Open the Oestrogen 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 Oestrogen 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 Oestrogen 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%

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

29 days ago today
Medication Oestrogen
Steady interest

#1,856 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
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
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
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

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Pharmacist Counseling Corner

Taking German Chamomile and Oestrogen Together: Common Questions

Can you take German Chamomile with Oestrogen?
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.
Why are there 3 interactions listed for German Chamomile and Oestrogen?
Oestrogen belongs to more than one drug category, and German Chamomile interacts with each of those categories a little differently. We list every one so nothing is missed — your overall risk is driven by the most serious of them.
How serious is the German Chamomile and Oestrogen 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.