Vitex (Chasteberry)
Vitex agnus-castus
TL;DR
Chasteberry extract acts on dopamine receptors to lower prolactin. The best-supported use is premenstrual syndrome and cyclical breast pain, where several RCTs beat placebo. Effects take three cycles.
Ideal For
- Premenstrual syndrome, particularly irritability, mood swings and breast tenderness
- Cyclical mastalgia after clinical assessment
- Short luteal phase or confirmed latent hyperprolactinaemia
- Irregular cycles where a prolactin-related cause has been identified
- Preference for a non-hormonal option before considering an SSRI or the pill for PMS
Avoid If
- Pregnant or breastfeeding
- Taking dopamine agonists (bromocriptine, cabergoline) or antipsychotics
- Hormone-sensitive cancer, including breast cancer
- Undergoing IVF or other assisted reproduction, unless your clinic approves
- Using hormonal contraception and relying on it — discuss with a clinician first
Frequently Asked Questions
Overview
Vitex agnus-castus, chasteberry, is the dried fruit of a Mediterranean shrub used in European gynaecological practice for decades and available as a licensed herbal medicine in Germany. Its actives — diterpenes, flavonoids and iridoid glycosides — bind dopamine D2 receptors in the pituitary, which suppresses prolactin secretion. Because prolactin restrains the luteal phase, lowering it can lengthen an inadequate luteal phase and raise progesterone.
Premenstrual syndrome is where the evidence is strongest. Placebo-controlled trials, including a well-known BMJ study using the Ze 440 extract, have reported meaningful reductions in irritability, mood swings, headache and breast fullness, with response rates around half of participants. Cyclical mastalgia responds similarly, and there is reasonable evidence in latent hyperprolactinaemia and luteal phase defect. A 2017 systematic review supported PMS and cyclical breast pain while judging the evidence in PCOS, infertility and menopause insufficient.
Two practical points define its use. It is slow: prolactin changes precede symptom changes, and trials measure outcomes across three menstrual cycles. And it is genuinely hormonally active, which means it should not be casually combined with hormonal contraception, dopamine agonists or antipsychotics.
How It Works
- Diterpenes bind pituitary dopamine D2 receptors as agonists, suppressing prolactin release
- Lower prolactin removes restraint on the luteal phase, supporting progesterone production and cycle regularity
- Reduced prolactin drive is the proposed mechanism for relief of cyclical breast tenderness
- Binds opioid and estrogen receptors in vitro, which may contribute to mood and vasomotor effects
- Does not contain phytoestrogens or hormones itself — the effect is via pituitary signalling
Quick Facts
- Regulates menstrual cycles
- Reduces PMS symptoms
- Lowers elevated prolactin
- Supports progesterone levels
- Improves luteal phase
Benefits & Outcomes
Prolactin Regulation
Vitex is the only common supplement with credible prolactin-lowering data, appropriate for mild cyclical symptoms.
Menopause Symptom Relief
Vitex is better suited to perimenopausal cycle irregularity and mood symptoms than postmenopausal vasomotor complaints, where its evidence is thin.
PMS Symptom Relief
Chasteberry is the best-supported option specifically for breast tenderness and premenstrual irritability.
Fertility Support Female
Consider for irregular cycles or short luteal phase; not a general fertility booster.
Estrogen Balance
Effective for PMS/cycle symptoms; indirect for estrogen balance specifically.
Menstrual Cycle Regulation
Cycle irregularity linked to luteal insufficiency often improves with chasteberry.
Progesterone Support
Vitex raises luteal progesterone indirectly rather than supplying or mimicking it.
Hormonal Balance
Vitex reliably lowers prolactin, which underpins its effects on cycle-related symptoms.
Reproductive Health
Vitex may help conception in women with luteal phase defects or mild hyperprolactinaemia.
Mood Stabilization
Premenstrual mood symptoms improve, but vitex is not a treatment for mood disorders.
Supporting Research16 studies
The treatment of premenstrual syndrome with preparations of Vitex agnus castus: a systematic review and meta-analysis
Verkaik S, Kamperman AM, van Westrhenen R +1 more
Trials with low risk of bias yielded substantially smaller effect sizes than weaker studies of Vitex agnus castus.
Vitex Agnus-Castus for the Treatment of Cyclic Mastalgia: A Systematic Review and Meta-Analysis
Ooi SL, Watts S, McClean R +1 more
Typical dosage was 20-40 mg/day with a treatment duration of 3 months.
Vitex agnus castus for premenstrual syndrome: a systematic review
Cerqueira RO, Frey BN, Leclerc E +1 more
All eight studies were positive for VAC in the treatment of PMS or PMDD and VAC was overall well tolerated.
Vitex agnus-castus for premenstrual syndrome: a systematic review and meta-analysis of randomised controlled trials
Verkaik S, Kamperman AM, van Westrhenen R +1 more
Vitex extract produced a large reduction in premenstrual symptom scores versus placebo
Herbal treatments for alleviating premenstrual symptoms: a systematic review
Dante G, Facchinetti F
Vitex agnus castus was the more investigated remedy (four trials, about 500 women), and it was reported to consistently ameliorate PMS better than placebo
Treatment for the premenstrual syndrome with agnus castus fruit extract: prospective, randomised, placebo controlled study
Schellenberg R
Responder rate was 52% with agnus castus versus 24% with placebo in women with premenstrual syndrome.
Herbs, vitamins and minerals in the treatment of premenstrual syndrome: a systematic review
Whelan AM, Jurgens TM, Naylor H
To identify herbs, vitamins and minerals advocated for the treatment of PMS and/or PMDD and to systematically review evidence from randomized controlled trials (RCTs) to determine their efficacy in reducing severity of PMS/PMDD symptoms.
The Effectiveness of Herbal Medicines on Cyclic Mastalgia: A Systematic Review on Meta-analysis
Mirzaee F, Fakari FR, Babakhanian M +2 more
Vitex-agnus-castus (SMD = - 0.642; 95%CI: - 0.84-- 0.44).
Vitex agnus-castus in latent hyperprolactinaemia and luteal phase defect: a randomized placebo-controlled study
Milewicz A, Gejdel E, Sworen H +3 more
Vitex reduced prolactin release and raised mid-luteal progesterone levels versus placebo
Vitex agnus-castus in premenstrual syndrome: a meta-analysis of double-blind randomised controlled trials
Csupor D, Lantos T, Hegyi P +6 more
Vitex was more effective than placebo, though most trials had methodological shortcomings and low certainty.
Effects of Vitex agnus and Flaxseed on cyclic mastalgia: A randomized controlled trial
Mirghafourvand M, Mohammad-Alizadeh-Charandabi S, Ahmadpour P +1 more
Group II received daily 3.2-4.8mg V. agnus tablet and placebo of Flaxseed.
Vitex agnus-castus extracts for female reproductive disorders: a systematic review of clinical trials
van Die MD, Burger HG, Teede HJ +1 more
Most trials favoured Vitex over placebo for premenstrual syndrome and cyclical mastalgia.
Treatment of moderate to severe premenstrual syndrome with Vitex agnus castus (BNO 1095) in Chinese women
Ma L, Lin S, Chen R +3 more
Premenstrual syndrome diary scores fell significantly more with Vitex than placebo across three cycles.
Comparison of the Effects of Vitagnus, Soy, and Vitagnus-soy Capsules on Premenstrual Syndrome in University Students: A Randomized Clinical Trial
Partovi Golshan R, Moradi M, Rakhshandeh H +1 more
This study aimed to compare the effects of the Vitagnus, soy, and Vitagnus-soy combination on PMS in students.
Vitamin B6 treatment of hyperprolactinaemia: effects on prolactin secretion
Delitala G, Masala A, Alagna S +1 more
Pyridoxine acutely suppressed prolactin release through dopaminergic stimulation, but the effect was short-lived
Therapeutic effect of Vitex agnus castus in patients with premenstrual syndrome
Zamani M, Neghab N, Torabian S
Symptom improvement occurred in 62% of the Vitex group versus 24% of the placebo group.
Safety Information
Potential Side Effects
Generally mild and uncommon. Nausea, headache, GI upset, acne, itching and a diffuse rash are the usual reports; some women notice changes in menstrual flow or spotting in the first cycles. Discontinuation rates in trials are low and comparable to placebo. It is contraindicated in pregnancy, and by suppressing prolactin it can reduce milk supply while breastfeeding.
Contraindications
Do not use in pregnancy or breastfeeding — it can reduce milk supply through prolactin suppression. Avoid alongside dopamine agonists and dopamine antagonists, where it may amplify or oppose the drug's action. Avoid in hormone-sensitive cancers. It should not be used with IVF protocols without the clinic's agreement. Prolactin elevation always warrants medical evaluation to exclude a pituitary adenoma before self-treating.
Drug Interactions
- Dopamine agonists (bromocriptine, cabergoline) — additive prolactin suppression; avoid combining
- Antipsychotics and metoclopramide — opposing dopaminergic actions; each may blunt the other
- Combined oral contraceptives and HRT — theoretical interference with hormonal effect; discuss with a clinician
- Fertility treatments including clomiphene and IVF protocols — unpredictable interaction with controlled stimulation
Pregnancy & Breastfeeding
Pregnancy: unsafe
Breastfeeding: likely_unsafe
Dosage Guidelines
Dosage Used in Studies
20-40 mg
Best Time to Take
Morning, once daily, taken continuously through the whole cycle
Best Form
A standardised extract equivalent to the Ze 440 preparation, 20 mg once daily
Bioavailability
Affects prolactin and other hormones via dopaminergic activity. Used for PMS and menstrual irregularities. Effects take 2-3 cycles. May affect fertility. Discontinue if pregnant.
Dosing by Goal
| Goal | Dose | Notes |
|---|---|---|
| Premenstrual syndrome | 20 mg daily of standardised extract (Ze 440 equivalent) | Taken continuously, not only in the luteal phase. Judge after three complete cycles. |
| Cyclical breast pain | 20-40 mg daily standardised extract | Trials report improvement over two to three cycles. Persistent or one-sided breast pain needs medical assessment first. |
| Latent hyperprolactinaemia / luteal phase defect | 20-40 mg daily | Only appropriate after a clinician has confirmed the diagnosis and excluded a pituitary adenoma. |
| Lower-concentration fruit extract | 400-500 mg daily | A common commercial format. Not directly comparable to the standardised trial doses. |
Forms Compared
Ze 440 standardised extract
Best for PMS
The extract used in the BMJ placebo-controlled trial, dosed at 20 mg daily. The best-characterised preparation.
BNO 1095 / Agnolyt-type extracts
Best for PMS, mastalgia
European licensed preparations used in several trials, typically 4-40 mg daily depending on standardisation.
Dried fruit extract capsules
Best for General use
Commonly 400-500 mg of a lower-concentration extract. Potency varies; look for standardisation to agnuside or casticin.
Tincture
Best for Traditional practice
Dosed in drops rather than milligrams, so comparison with trial doses is unreliable.
Food & Timing
Take in the morning with water, traditionally before breakfast. Food does not appear to matter much.
Medical Disclaimer
The information provided on this website is for educational and informational purposes only and is not intended as a substitute for professional medical advice, diagnosis, or treatment. Always seek the advice of your physician or other qualified health provider with any questions you may have regarding a medical condition or before starting any supplement regimen.
Individual results may vary. The statements on this website have not been evaluated by the Food and Drug Administration. Products and information are not intended to diagnose, treat, cure, or prevent any disease.