Herb & supplement monograph

Vitex Agnus-castus Drug Interactions, Uses, Effectiveness, Safety & More

Medically reviewed by Dr. Brian Staiger, PharmD, BCPS ·Updated July 2026

What is this page for?

First and foremost: how Vitex Agnus-castus interacts with medications. The heart of this page is the interaction list — every drug Vitex Agnus-castus is known to interact with, and how serious each one is.

But these pages have grown well beyond that into a full monograph — what Vitex Agnus-castus is, what people use it for and how strong the evidence is, its safety and side effects, and answers to the questions we’re asked most — written and reviewed by the clinical staff at HelloPharmacist. It’s educational information from our licensed clinical databases, not medical advice, and we don’t sell or endorse products. Our editorial policy

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Vitex Agnus-castus Drug Interactions: The Bottom Line

From the HelloPharmacist Editorial Team · Updated July 2026

Based on the available evidence, the overall risk of a clinically significant Vitex Agnus-castus drug interaction appears low for most people, though it deserves a closer look if you take hormonal or dopamine-related medications. None of the listed interactions are rated major, and nearly all are theoretical concerns rather than effects confirmed in well-controlled human studies.

Interactions deserving the most attention

The best-supported concern involves estrogens, since vitex has hormone-modulating activity that could reduce the benefit of hormone replacement therapy. For the same reason, there is a theoretical chance it could make oral contraceptives less reliable, which matters because these depend on steady hormone effects. Vitex may also act on dopamine in the brain, so it could theoretically work against antipsychotic drugs and metoclopramide, or add to the effects of dopamine agonists used for conditions like Parkinson's disease.

What the rest of the list means

Vitex appears on a long list of medications, but a long list does not mean every combination is harmful. Most of these interactions are predicted from how vitex might act on hormones or dopamine, not from documented problems in people. Human evidence is limited across the board, so these remain precautions rather than proven effects.

Check your medications against Vitex Agnus-castus

Based on HelloPharmacist’s Vitex Agnus-castus interaction data and reviewed under our editorial standards.

Interaction report

Drugs that interact with Vitex Agnus-castus

121 medications have a known interaction with Vitex Agnus-castus, graded by severity. Select any drug for the full evidence-based detail.

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Tell us the medications you take and we’ll check each one against Vitex Agnus-castus using our pharmacist-reviewed interaction data.

AI summaries are generated from our Vitex Agnus-castus interaction data for education only — always confirm with your pharmacist. How we use AI

2,830 drugs

Read The List Like a Pharmacist

What Severity, Likelihood & Evidence Mean

Severity — How Serious It Can Be

Major. Clinically significant; generally best avoided, or used only under direct professional supervision.
Moderate. May need monitoring, a dose adjustment, or separating the times you take each one.
Minor. Generally not clinically significant, but still worth noting and mentioning to your pharmacist.
No known interaction. Checked against our sources with nothing documented — not the same as proven safety.

Likelihood — How Well It’s Documented

Likely. Well-controlled human studies have demonstrated the likely existence of this interaction
Probable. 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.
Possible. 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
Unlikely. Interaction has been demonstrated in animal or in lab research but has been shown not to occur in humans.

Where This Data Comes From

Interaction records are evidence-graded and sourced from the Natural Medicines database (TRC Healthcare), the same reference used by pharmacists and hospitals.
Each drug listed above links to the full report for that exact Vitex Agnus-castus combination — clinical detail, likelihood, evidence level, and citations.
Content is reviewed by licensed HelloPharmacist pharmacists — see our data sources and editorial standards.

The big picture

The kinds of drugs Vitex Agnus-castus affects

Every type of medication (drug category) Vitex Agnus-castus is known to interact with. Open any category for the detail — or search your exact drug in the checker above.

All 5 drug categories Vitex Agnus-castus interacts with

Antipsychotic DrugsContraceptive DrugsDopamine AgonistsEstrogensMetoclopramide (reglan)

Antipsychotic Drugs

Theoretically, vitex agnus-castus could interfere with the activity of antipsychotic drugs.
Vitex agnus-castus might interfere with the action of dopamine antagonists such as antipsychotic drugs due to its dopamine agonist effects.

Likelihood Possible Evidence D

Contraceptive Drugs

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.

Likelihood Possible Evidence B

Dopamine Agonists

Theoretically, vitex agnus-castus could interfere with dopamine agonists.
Vitex agnus-castus might potentiate the actions of dopaminergic agonists due to possible dopaminergic effects.

Likelihood Possible Evidence D

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.

Likelihood Probable Evidence D

Metoclopramide (Reglan)

Theoretically, dopaminergic effects of vitex agnus-castus could interfere with metoclopramide.
Vitex agnus-castus might interfere with the action of dopamine antagonists such as metoclopramide due to its possible dopaminergic effects.

Likelihood Possible Evidence D

Monograph

Vitex Agnus-castus: Uses, Safety & Side Effects

Medically reviewed by Dr. Brian Staiger, PharmD, BCPS · Reviewed July 2026 ·

The bottom line

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.

Scientific name: Vitex agnus-castus
Family: Lamiaceae
Part used: Dried ripe fruit (berries)
Common forms: Capsules, tablets, liquid extracts (tinctures), and teas

People commonly use it for

Premenstrual syndrome (PMS)
Irregular or absent menstrual periods
Cyclical breast pain (mastalgia)
Menopause symptoms
Fertility support

Popular and traditional uses — not proof it works. See “Uses & effectiveness” below for the evidence.

Safety at a glance

OverallUse caution

Often well tolerated short-term, but it may affect hormones, so use under guidance.

PregnancyPossibly Unsafe

When used orally. Theoretically, the hormonal effects of vitex agnus-castus might adversely affect pregnancy or lactation. Animal research shows that...

Read the full pregnancy detail

BreastfeedingPossibly Unsafe

When used orally. Theoretically, the hormonal effects of vitex agnus-castus might adversely affect pregnancy or lactation. Animal research shows that...

Read the full breastfeeding detail

Pregnancy & breastfeeding ratings are from Natural Medicines (Therapeutic Research Center). Safety guidance is general; always confirm with your pharmacist or doctor for your situation.

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Overview

Vitex, often called chasteberry or chaste tree berry, comes from the dried fruit of the chaste tree (Vitex agnus-castus). The plant is native to the Mediterranean region and parts of central Asia, and it is now grown in warm climates around the world. The small, peppery berries have been used in traditional medicine for a very long time.

Today, vitex is most popular as a supplement for women's health concerns, especially premenstrual syndrome (PMS) and irregular menstrual cycles. It is sold as capsules, tablets, liquid extracts, and teas, and is sometimes combined with other herbs in women's health formulas.

How it works

Vitex is thought to act on the brain's pituitary gland, which helps control reproductive hormones. Laboratory and animal research suggests compounds in the berries may influence dopamine activity, which in turn can lower levels of a hormone called prolactin. Changes in prolactin may affect the balance of other hormones involved in the menstrual cycle.

The berries contain a mix of plant compounds, including flavonoids, iridoid glycosides (such as agnuside), and essential oils, which are believed to contribute to these effects. It is important to know that much of this is based on lab and animal studies, so the exact way vitex works in the human body is not fully understood.

Effectiveness

Does Vitex Agnus-castus work?

Here’s what the research actually shows for each use — graded by Natural Medicines and reviewed by Dr. Brian Staiger, PharmD.

Evidence overview · 23 uses evaluated

2 Possibly effective 1 Leans ineffective 20 Insufficient evidence

How to read these evidence grades

Natural Medicines’ 7-point scale. We show each rating’s label word-for-word.

1EffectiveStrong, consistent evidence it works.

2Likely EffectiveGood evidence, though not yet conclusive.

3Possibly EffectiveSome evidence suggests a benefit.

4Possibly IneffectiveSome evidence it may not help.

5Likely IneffectiveFairly strong evidence it doesn’t help.

6IneffectiveStrong evidence it doesn’t work.

7Insufficient Reliable Evidence to RateToo little research to say either way.

Possibly Effective Mastalgia