Know2eat

Chasteberry (vitex)

Vitex agnus-castus

Herbs & Botanicals

What chasteberry (vitex) may help with

Ranked by how strong the human evidence is — best supported first.

Best supportedMenopausal symptomsLimited evidence· 4 sources

Then, in order

About Chasteberry (vitex)

A dried fruit extract used for premenstrual symptoms and cycle irregularity, standardised variously to casticin, agnuside or an extract ratio. It acts on the pituitary rather than as a phytoestrogen.

Chasteberry has a moderate body of German trials in premenstrual syndrome, several of them reasonably designed and most funded by the manufacturers of branded extracts. Its dopaminergic effect on prolactin is genuine, which is also why it can interfere with dopamine-related medication and with fertility treatment. Extracts differ enough that the trials describe specific products rather than the plant.

Sold as
Standardised fruit extract tablet, Capsule, Tincture, Combination formulas
Standardised to
Branded extracts state a native extract ratio, sometimes with casticin or agnuside content — a product without this marker may not resemble what was studied.
Also known as
Vitex, Chaste tree berry, Agnus castus, Monk’s pepper

Regulation: Approved in Germany as a medicine for premenstrual complaints and cycle irregularities, and sold as a supplement elsewhere without that assessment.

What the research used

The amounts, forms and durations published trials of Chasteberry (vitex) actually administered.

These are the amounts published trials administered — not a recommendation, and not a dose to copy. Trial participants were screened, supervised and given a characterised preparation. What is in a retail bottle is frequently not what was studied, and the amount that suits one person is not general advice.

  • Studied for Premenstrual syndrome

    20–40 mg

    Limited

    Standardised dried extract, once daily · 3 menstrual cycles

    These are native extract weights of specific branded German products, mostly tested in manufacturer-funded trials. Crude fruit powder products at several hundred milligrams are not comparable.

  • Studied for Cyclical breast pain

    4–40 mg

    Limited

    Extract or tincture, daily · 2–3 cycles

    Trials used different preparations including a tincture measured in drops, which makes cross-product dose comparison unreliable.

This is general information about food, not medical advice. It cannot diagnose, treat or replace guidance from a clinician who knows your history.

When it was taken

Each window says whether a trial compared it against an alternative, or whether it is convention and pharmacology. Most timing advice is the second kind.

None of the timings below were directly compared in a trial. They reflect how the research happened to dose, or what the pharmacology implies — which is not the same as a timing being better.

  • Morning

    Limited

    Dosed in the morning in most trials, on the reasoning that prolactin secretion peaks overnight. That is pharmacological reasoning, not a tested comparison.

    Timing was not directly compared. This reflects convention or how the compound behaves in the body, not a trial showing this window works better.

The evidence in depth

Best supported: Limited

What each association actually rests on, and the papers behind it. A rating describes the state of the research, not how promising the supplement sounds. How we rate evidence.

Menopausal symptoms

Women's Health
Limited evidence

Several randomised trials report reduced premenstrual symptom scores over three cycles compared with placebo, and some report reduced cyclical breast pain. Most trials were funded by the makers of the extract tested, and results for menopausal symptoms specifically are much weaker.

What may be going on: Dopaminergic compounds in the fruit bind D2 receptors and lower prolactin secretion.

Limited evidence. Early human work, or mostly lab and animal research.

View the 4 sources

Deep research mode adds each paper’s own conclusion and stated limitations.

Mood

Mental Wellbeing
Not enough evidence

Evidence is limited for chasteberry and mood outside the premenstrual context. Premenstrual dysphoric disorder trials are few and small.

Not enough evidence. Not enough human research to say anything useful yet.

View the 2 sources

Deep research mode adds each paper’s own conclusion and stated limitations.

Things to know

Interactions, contraindications and dose limits, most serious first. Concentrated extracts interact with medication in ways the whole plant does not, so this section carries more weight here than it does on a food page.

  • Interaction

    Dopamine-related medication

    Interacts withAntipsychotics, bromocriptine, cabergoline, metoclopramide

    Chasteberry acts on dopamine D2 receptors, so it can oppose antipsychotics and add to dopamine agonists such as bromocriptine and cabergoline. This is a pharmacologically real interaction, not a theoretical one.

  • Worth knowing

    Fertility treatment and ovarian stimulation

    Because it alters prolactin and gonadotrophin signalling, chasteberry can interfere with fertility monitoring and treatment, and cases of ovarian hyperstimulation have been reported alongside assisted reproduction.

  • Avoid

    Pregnancy and breastfeeding

    Chasteberry should be stopped once pregnancy is confirmed. Its prolactin-lowering effect also makes it a poor choice while breastfeeding, despite occasional traditional use for the opposite purpose.

  • Interaction

    Hormonal contraception and hormone therapy

    Interacts withOral contraceptives, hormone replacement therapy

    Effects on the hypothalamic-pituitary axis may interfere with hormonal contraception and hormone replacement therapy.

  • Worth knowing

    Hormone-sensitive conditions

    Safety in breast cancer and other hormone-sensitive conditions has not been established, and it is generally avoided in those situations.

Evidence ratings on this page: 1 limited evidence, 1 not enough evidence.

Supplements are sold in the US without pre-market review of efficacy or safety. Nothing on this page is a recommendation to take Chasteberry (vitex), or a dose to follow.