Drug & supplement interaction

German Chamomile + Ethinyl estradiol, Levonogestrel

Ethinyl estradiol, Levonogestrel brand name: Lybrel.

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

Ethinyl estradiol, Levonogestrel falls into 4 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
Interactions4
EvidenceD
What do Severity, Likelihood & Evidence mean?
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Interaction report

German Chamomile and Ethinyl estradiol, Levonogestrel

These two interact in 4 distinct ways. Each one is explained separately below.

Why Are There 4 Interactions?

German Chamomile interacts with whole categories of medication. Ethinyl estradiol, Levonogestrel falls into 4 of those categories, so it can interact with German Chamomile in 4 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 4

Why this applies to Ethinyl estradiol, Levonogestrel

Ethinyl estradiol, Levonogestrel 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

If you take Lybrel (a birth control pill that combines ethinyl estradiol and levonorgestrel), here's the gist. Both hormones are partly broken down by a liver enzyme called CYP3A4. German chamomile, mostly studied as a tea, has shown in lab dish experiments that it might slow that same enzyme down. In theory, that could let a little more hormone build up in your body, which might mean more of the usual estrogen-type side effects like nausea, breast tenderness, headaches, or bloating.

I want to be honest though: this is based only on test-tube work, and it has never actually been reported in people. The 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.

Contact Dr. Brian directly if you have additional questions on this interaction
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

CONTRACEPTIVE DRUGS

2 of 4

Ethinyl estradiol, Levonogestrel also falls under CONTRACEPTIVE DRUGS.

Theoretically, large amounts of German chamomile might reduce the effectiveness of oral contraceptives.
In vitro, German chamomile has demonstrated antiestrogenic activity. Theoretically, concomitant use of large amounts of German chamomile might interfere with contraceptive drugs 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 situation with your Lybrel (a birth control pill that combines ethinyl estradiol with levonorgestrel). In lab studies only, German chamomile has shown mild antiestrogenic activity, meaning it may compete with estrogen at its receptors. The thinking is that very large amounts of chamomile could, in theory, blunt the estrogen part of your pill and slightly lower how well it prevents pregnancy.

I want to be honest: this is theoretical and based on test-tube data, not real people. A normal cup or two of chamomile tea is very unlikely to cause trouble. The concern is mainly with concentrated chamomile supplements taken in big doses. If you use those regularly, just mention it to your pharmacist or doctor so you can stay protected.

Contact Dr. Brian directly if you have additional questions on this interaction
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
Moderate

ESTROGENS

3 of 4

Ethinyl estradiol, Levonogestrel 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

Lybrel combines two hormones, ethinyl estradiol (an estrogen) and levonorgestrel, to prevent pregnancy. The concern here is mostly theoretical. In lab dishes, German chamomile has shown some anti-estrogen activity, meaning it might compete a little at estrogen receptors. On paper, that could blunt the estrogen part of your pill.

Here's my honest take: this comes only from test-tube data, not real people, and a normal cup or two of chamomile tea is very unlikely to cause any problem. There's no good evidence that everyday tea makes your birth control fail. If you're using large, concentrated chamomile supplements, that's worth mentioning to your pharmacist or doctor, just to be safe.

Contact Dr. Brian directly if you have additional questions on this interaction
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

4 of 4

Ethinyl estradiol, Levonogestrel 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

If you enjoy chamomile tea while taking Lybrel (your ethinyl estradiol and levonorgestrel birth control pill), here's the honest picture. Lab and animal studies hint that chamomile may gently slow down an enzyme called CYP1A2, which helps clear the estrogen part of your pill. In theory, that could let estrogen levels nudge a little higher, which might mean more of the usual estrogen-type effects like nausea, breast tenderness, bloating, or headache.

That said, this has never actually been reported in people, and the evidence is only test-tube and animal data, so it's considered minor. A normal cup or two of chamomile tea is very unlikely to cause trouble. If you take concentrated chamomile supplements or notice new symptoms, just check in with your pharmacist or doctor.

Contact Dr. Brian directly if you have additional questions on this interaction
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 Ethinyl estradiol, Levonogestrel one above is among them. If you take anything else, check it against the full list below.

Moderate 924 Minor 35 No known interaction 1,871 (incl. Ethinyl estradiol, Levonogestrel)
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 Ethinyl estradiol, Levonogestrel

This page covers German Chamomile only. If you take other supplements — a multivitamin, a sleep aid, something for joints — the Ethinyl estradiol, Levonogestrel page lists 239 supplements it has a documented interaction with, worst first, each one explained.

The most serious there right now: Activated Charcoal (major), Beer (major), Grapefruit (major), Siberian Cocklebur (major) and St. John's Wort (major).

By severity: 6 major · 195 moderate · 38 minor.

From our pharmacist’s overview on the Ethinyl estradiol, Levonogestrel page

“A daily birth control pill like Lybrel (ethinyl estradiol with levonorgestrel) only works when enough hormone stays in the bloodstream, and that is exactly what several supplements on this page can undermine. This list deserves genuine care, starting with the six major-rated entries.”

Reviewed by 2 · Jul 18, 2026

Open the Ethinyl estradiol, Levonogestrel 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 Ethinyl estradiol, Levonogestrel 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 Ethinyl estradiol, Levonogestrel 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%

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

29 days ago today
Medication Ethinyl estradiol, Levonogestrel
Top 5%

#118 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
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 Ethinyl estradiol, Levonogestrel, 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 Ethinyl estradiol, Levonogestrel supplement interactions › Every supplement checked against Ethinyl estradiol, Levonogestrel, 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 Ask a pharmacist › Free, personal answer from our licensed team
Pharmacist Counseling Corner

Taking German Chamomile and Ethinyl estradiol, Levonogestrel Together: Common Questions

Can you take German Chamomile with Ethinyl estradiol, Levonogestrel?
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 4 interactions listed for German Chamomile and Ethinyl estradiol, Levonogestrel?
Ethinyl estradiol, Levonogestrel 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 Ethinyl estradiol, Levonogestrel 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.