Drug & supplement interaction

Vitex Agnus-castus + Brexpiprazole

Brexpiprazole brand name: Rexulti.

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

Brexpiprazole 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 the activity of antipsychotic drugs.

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

Vitex Agnus-castus and Brexpiprazole

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. Brexpiprazole 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

ANTIPSYCHOTIC DRUGS

1 of 2

Why this applies to Brexpiprazole

Brexpiprazole falls under ANTIPSYCHOTIC DRUGS — the group Vitex Agnus-castus interacts with.

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.
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 idea behind this one. Brexpiprazole (Rexulti) works partly by calming down dopamine signaling in the brain. Vitex, on the other hand, is thought to do the opposite, gently nudging dopamine activity up. So in theory, the two could work against each other, and that pull in opposite directions might make your brexpiprazole a little less effective at controlling symptoms like disturbed thinking, mood swings, or low mood.

I want to be honest about the evidence though: this concern comes only from lab and animal studies, not from real patients. It's a theoretical worry, not something proven. Still, since brexpiprazole treats serious conditions, I wouldn't add Vitex on your own. Please run it by your pharmacist or prescriber first, and let them know right away if your symptoms seem to slip.

Contact Dr. Brian directly if you have additional questions on this interaction
References
  1. Wuttke W. Dopaminergic action of extracts of Agnus Castus. Forschende Komplementarmedizen 1996;3:329-30.
  2. Jarry H, Leonhardt S., Gorkow C, Wuttke W. In vitro prolactin but not LH and FSH release is inhibited by compounds in extracts of Agnus Castus: direct evidence for a dopaminergic principle by the dopamine receptor assay. Exp Clin Endocrinol 1994;102:448- PubMed
Moderate

DOPAMINE AGONISTS

2 of 2

Brexpiprazole also falls under 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.
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 wrinkle with this pairing. Vitex (chasteberry) may nudge dopamine activity in the brain, while brexpiprazole (Rexulti) works the opposite way for the most part, calming down overactive dopamine signaling. So in theory, vitex could tug against what your medication is trying to do, possibly making it work a little less smoothly.

I want to be straight with you: this concern comes only from lab and animal research, not from real patients, so it's largely theoretical and may never cause a noticeable problem. Still, if you take Rexulti and notice your symptoms creeping back, or any new restlessness or mood changes after starting vitex, that's worth a quick chat. Please loop in your pharmacist or prescriber before adding chasteberry, just so someone keeps an eye on things.

Contact Dr. Brian directly if you have additional questions on this interaction
References
  1. Meier B, Berger D, Hoberg E, et al. Pharmacological activities of Vitex agnus-castus extracts in vitro. Phytomedicine 2000;7:373-81. 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 Brexpiprazole 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. Brexpiprazole)
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 Brexpiprazole

This page covers Vitex Agnus-castus only. If you take other supplements — a multivitamin, a sleep aid, something for joints — the Brexpiprazole page lists 177 supplements it has a documented interaction with, worst first, each one explained.

The most serious there right now: Activated Charcoal (major), Grapefruit (major), Indian Snakeroot (major), Lithium (major) and Rauvolfia Vomitoria (major).

By severity: 6 major · 130 moderate · 41 minor.

From our pharmacist’s overview on the Brexpiprazole page

“Brexpiprazole (Rexulti) treats schizophrenia and is added to antidepressants for depression, and its supplement list warrants real care before you add anything to it. The bulk of the 177 entries change how your liver clears the drug, so grapefruit can push levels up while St.”

Reviewed by 2 · Jul 18, 2026

Open the Brexpiprazole 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 Brexpiprazole 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 Brexpiprazole 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
Top half

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

29 days ago today
Medication Brexpiprazole
Steady interest

#1,803 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
Medication

About Brexpiprazole

What Is Brexpiprazole Used For?

Brand name: Rexulti

Brexpiprazole tablets are approved for two uses in adults: as an add-on (adjunctive) treatment alongside antidepressants for major depressive disorder (MDD), and as a treatment for schizophrenia. These uses apply to both the generic brexpiprazole tablets and Rexulti.

Rexulti has one additional approved use: treating agitation associated with dementia due to Alzheimer's disease in adults. Rexulti is also approved for schizophrenia in adolescents ages 13 and older. Note that Rexulti is not approved for dementia-related psychosis without agitation from Alzheimer's disease, and it is not meant to be used on an as-needed basis for Alzheimer's-related agitation.

See full Brexpiprazole drug information
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 Brexpiprazole, 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 Brexpiprazole supplement interactions › Every supplement checked against Brexpiprazole, ranked by severity Brexpiprazole 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 Vitex Agnus-castus and Brexpiprazole Together: Common Questions

Can you take Vitex Agnus-castus with Brexpiprazole?
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 Brexpiprazole?
Brexpiprazole 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 Brexpiprazole 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.