Drug & supplement interaction

Vitex Agnus-castus + Ethinyl Estradiol, Levonorgestrel

Ethinyl Estradiol, Levonorgestrel brand names: Levlite 28, Tri-Levlen 21, Tri-Levlen 28, Levlite, Trivora-28, and others.

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

Ethinyl Estradiol, Levonorgestrel falls into 2 drug categories that Vitex Agnus-castus can interact with; the most serious is rated moderate. Theoretically, vitex agnus-castus could interfere with oral contraceptives.

Read the full interaction report
SeverityModerate
LikelihoodPossible
Interactions2
EvidenceB
What do Severity, Likelihood & Evidence mean?
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Interaction report

Vitex Agnus-castus and Ethinyl Estradiol, Levonorgestrel

These two interact in 2 distinct ways. Each one is explained separately below.

Why Are There 2 Interactions?

Vitex Agnus-castus interacts with whole categories of medication. Ethinyl Estradiol, Levonorgestrel falls into 2 of those categories, so it can interact with Vitex Agnus-castus in 2 different ways. We’ve listed each one below — your overall risk is driven by the most serious of them (Moderate).

Moderate

CONTRACEPTIVE DRUGS

1 of 2

Why this applies to Ethinyl Estradiol, Levonorgestrel

Ethinyl Estradiol, Levonorgestrel falls under CONTRACEPTIVE DRUGS — the group Vitex Agnus-castus interacts with.

Theoretically, vitex agnus-castus could interfere with oral contraceptives.
Vitex agnus-castus might interfere with the efficacy of oral contraceptives due to possible hormone modulating activity.
Severity Moderate Likelihood Possible Evidence B

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're taking your birth control pill (the ethinyl estradiol and levonorgestrel combo found in brands like Trivora and Triphasil) and thinking about adding Vitex, here's the concern. Vitex can nudge your body's hormone signals, mainly by lowering a hormone called prolactin and possibly shifting your estrogen and progesterone balance. In theory, that hormonal tug-of-war could work against the steady hormone levels your pill relies on to prevent pregnancy.

I want to be honest: this is a theoretical worry, not something proven to cause failed contraception. Still, since the stakes are high (an unplanned pregnancy or breakthrough bleeding), I'd play it safe. Please check with your pharmacist or doctor before combining them, and consider a backup method like condoms in the meantime.

Contact Dr. Brian directly if you have additional questions on this interaction
References
  1. Liu J, Burdette JE, Xu H, et al. Evaluation of estrogenic activity of plant extracts for the potential treatment of menopausal symptoms. J Agric Food Chem 2001;49:2472-9.. PubMed
  2. Wuttke W, Jarry H, Christoffel V, et al. Chaste tree (Vitex agnus-castus)--pharmacology and clinical indications. Phytomedicine 2003;10:348-57. PubMed
Moderate

ESTROGENS

2 of 2

Ethinyl Estradiol, Levonorgestrel also falls under ESTROGENS.

Theoretically, vitex agnus-castus could interfere with the activity of estrogens.
Vitex agnus-castus has hormone modulating activity that can interfere with the efficacy of hormone replacement therapy.
Severity Moderate Likelihood Probable Evidence D

Interaction 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..

Dr. Brian Staiger, PharmD, BCPS
Dr. Brian Staiger explains PharmD, Clinical Pharmacist

The pill you're asking about combines two hormones, ethinyl estradiol (an estrogen) and levonorgestrel (a progestin), to prevent pregnancy and steady your cycle. Vitex (chasteberry) tinkers with your body's own hormone signals, mainly through the pituitary gland and prolactin, so in theory it could work against the hormones in your birth control. That raises a concern about reduced effectiveness, things like breakthrough bleeding, spotting, or even a weaker contraceptive effect.

I'll be honest with you: this caution comes from lab and animal research, not solid human studies, so the real-world risk is uncertain. Still, since pregnancy prevention is too important to gamble on, please run this combo by your pharmacist or doctor before pairing them, and consider a backup method.

Contact Dr. Brian directly if you have additional questions on this interaction
References
  1. Liu J, Burdette JE, Xu H, et al. Evaluation of estrogenic activity of plant extracts for the potential treatment of menopausal symptoms. J Agric Food Chem 2001;49:2472-9.. PubMed
  2. Wuttke W, Jarry H, Christoffel V, et al. Chaste tree (Vitex agnus-castus)--pharmacology and clinical indications. Phytomedicine 2003;10:348-57. 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

Vitex Agnus-castus Also Interacts With Other Medications

Vitex Agnus-castus has 120 moderate known drug interactions in our database — the Ethinyl Estradiol, Levonorgestrel one above is among them. If you take anything else, check it against the full list below.

Moderate 120 No known interaction 2,710 (incl. Ethinyl Estradiol, Levonorgestrel)
Taking anything else?

Check Another of Your Medications Against Vitex Agnus-castus

Covers the 2,830 medications we’ve checked against Vitex Agnus-castus. Pick one to open its full report.

Everything else you take

See Every Supplement That Interacts With Ethinyl Estradiol, Levonorgestrel

This page covers Vitex Agnus-castus only. If you take other supplements — a multivitamin, a sleep aid, something for joints — the Ethinyl Estradiol, Levonorgestrel 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.

Open the Ethinyl Estradiol, Levonorgestrel interaction page

One more smart check

Taking Vitex Agnus-castus as Part of a Dietary Supplement Product? Check It for Interactions

We hold 45 real supplement products containing Vitex Agnus-castus, each one broken down to its full ingredient list — and combination products often carry several ingredients besides Vitex Agnus-castus. Your product may carry other ingredients that interact with Ethinyl Estradiol, Levonorgestrel too, on top of Vitex Agnus-castus — 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 Vitex Agnus-castus and Ethinyl Estradiol, Levonorgestrel 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 Vitex Agnus-castus
Steady interest

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

29 days ago today
Medication Ethinyl Estradiol, Levonorgestrel
Top 25%

#400 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 Vitex Agnus-castus

What is Vitex Agnus-castus?

Vitex Agnus-castus
  • Premenstrual syndrome (PMS)
  • Irregular or absent menstrual periods
  • Cyclical breast pain (mastalgia)
  • Menopause symptoms
  • Fertility support

Vitex (chasteberry) is an herbal remedy most often used for PMS and menstrual cycle problems, and the strongest evidence is for easing some PMS symptoms. It is generally well tolerated by many adults, but it can affect hormone-related processes, so anyone who is pregnant, breastfeeding, or has a hormone-sensitive condition should talk with a healthcare professional first.

Read the full Vitex Agnus-castus monograph & all interactions
Keep checking

Other Drugs & Vitex Agnus-castus

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

0Major
120Moderate
0Minor
2,709No known interaction
120 Moderate 2,709 No interaction
Moderate

120 interactions

Showing 60 of 120 moderate interactions — see all 120 on the Vitex Agnus-castus page.

No interaction 2,709 drugs checked — show the list

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

Showing the 60 most looked-up of 2,709 medications checked with no known interaction — see the full Vitex Agnus-castus list.

See the full Vitex Agnus-castus interactions page
See every supplement checked against Ethinyl Estradiol, Levonorgestrel, 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
Vitex Agnus-castus monograph › Uses, safety, and every drug interaction in one place Ethinyl Estradiol, Levonorgestrel supplement interactions › Every supplement checked against Ethinyl Estradiol, Levonorgestrel, 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 Vitex Agnus-castus and Ethinyl Estradiol, Levonorgestrel Together: Common Questions

Can you take Vitex Agnus-castus with Ethinyl Estradiol, Levonorgestrel?
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 2 interactions listed for Vitex Agnus-castus and Ethinyl Estradiol, Levonorgestrel?
Ethinyl Estradiol, Levonorgestrel belongs to more than one drug category, and Vitex Agnus-castus 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 Vitex Agnus-castus and Ethinyl Estradiol, Levonorgestrel 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.