Chasteberry (Vitex)
Summary
Chasteberry is mainly studied for premenstrual syndrome (PMS). Well-described extracts beat placebo in several trials (grade B), but most trials carry a high risk of bias and placebo responses reach about 50%. Breast-pain data are moderate; a menopause combination with St John's wort did no better than placebo. NCCIH and LactMed advise against use in pregnancy, breastfeeding and hormone-sensitive cancers.
Key facts
- Extracts of the dried fruit of Vitex agnus-castus; trials mostly used the standardized extracts Ze 440 and BNO 1095[1][5]
- PMS symptoms: 52% of women responded on Ze 440 vs 24% on placebo over three menstrual cycles (B)[2]
- Across three well-reported trials (520 women), remission was 2.57 times as likely as on placebo[5]
- A broader meta-analysis found most PMS trials at high risk of bias, with extreme heterogeneity (I² 91%) and signs of publication bias[6]
- 20 mg/day of Ze 440 beat 8 mg and placebo; 30 mg added no further benefit[4]
- A Vitex plus St John's wort combination was no better than placebo for hot flushes over 16 weeks[8]
- 6 graded human outcomes on this page
- October 12, 2026
How it works
ProposedSome chasteberry constituents, possibly diterpenes, bind dopamine D2 receptors in the pituitary. Prolactin rises at low doses and may fall at high doses, which is the proposed link to premenstrual breast symptoms; this has not been confirmed as the cause of the trial results.[9][7]
What the human research says
Human trials only, one row per outcome. The form column shows what each trial actually tested. Grades follow our evidence-grading policy.
At a glance: strongest evidence per outcome
| Outcome | Grade | Effect | Strongest evidence | Rows |
|---|---|---|---|---|
| Breast pain | Grade B | Improved | Meta-analysis of 6 trials · n = 718 · 2020 | 1 row |
| PMS | Grade B | Improved | Meta-analysis of 3 trials · n = 520 · 2019 | 4 rows |
| Menopause | Grade C | No effect | RCT · n = 100 · 2009 | 1 row |
Every graded row
| Outcome | Effect | Grade | Best evidence | PMID |
|---|---|---|---|---|
| Cyclical breast pain | Improved | Grade B | Meta-analysis · n = 718 · 2020 Women of reproductive age with cyclical breast pain Form: Vitex agnus-castus extracts · Dose: Typically 20–40 mg/day · Duration: Typically 3 months A conservative pooled analysis of 6 placebo-controlled trials found a moderate benefit over placebo (SMD 0.67). Risk of bias was unclear in most studies. | 31464546 (opens PubMed)Source [7] |
| PMS remission (responder rate) | Improved | Grade B | Meta-analysis · n = 520 · 2019 Women with PMS in double-blind trials of well-characterized extracts Form: Ze 440 and BNO 1095 extracts · Dose: As in the pooled trials · Duration: Up to 3 menstrual cycles Women on chasteberry were 2.57 times as likely to have symptom remission as those on placebo (95% CI 1.52–4.35). Only 3 of 21 trials met reporting standards for inclusion. | 31780016 (opens PubMed)Source [5] |
| PMS diary and PMTS scores | Improved | Grade B | RCT · n = 208 · 2009 Chinese women with moderate to severe premenstrual syndrome Form: BNO 1095 extract · Dose: Extract corresponding to 40 mg of dried fruit daily · Duration: 3 menstrual cycles PMS diary score fell by 22.7 points vs 15.5 with placebo. The authors reported a placebo effect of about 50%. No serious adverse events. | 19269753 (opens PubMed)Source [3] |
| PMS symptom score and responder rate | Improved | Grade B | RCT · n = 170 · 2001 Women with premenstrual syndrome in German community clinics (mean age 36) Form: Ze 440 dry fruit extract tablet · Dose: One tablet daily (mg per tablet not stated in the abstract) · Duration: 3 menstrual cycles Symptom scores (irritability, mood, anger, headache, breast fullness, bloating) improved more than with placebo; 52% vs 24% had at least a 50% drop. Mild side effects in 4 vs 3 women. | 11159568 (opens PubMed)Source [2] |
| PMS total symptom score by dose | Improved | Grade C | RCT · n = 162 · 2012 Women aged 18–45 with premenstrual syndrome Form: Ze 440 extract · Dose: 8, 20 or 30 mg/day vs placebo · Duration: 3 menstrual cycles 20 mg/day improved symptoms more than placebo and 8 mg; 30 mg was not better than 20 mg. All doses were well tolerated. | 23022391 (opens PubMed)Source [4] |
| Hot flushes and menopausal symptoms | No effect | Grade C | RCT · n = 100 · 2009 Late-perimenopausal and postmenopausal women with hot flushes Form: Combination of St John's wort and Vitex agnus-castus tablets · Dose: Twice daily (amounts not stated in the abstract) · Duration: 16 weeks No difference from placebo for hot flushes, Greene Climacteric Scale, depression scores or quality of life; both groups improved. | 18791483 (opens PubMed)Source [8] |
Forms
| Form | Elemental % | Absorption (human data) | GI tolerance | Studied for |
|---|---|---|---|---|
| Ze 440 standardized fruit extract | Varies[2][4] | No human absorption data in our sources.[1] | Mild adverse events, similar to placebo, over three menstrual cycles.[2][4] | PMS (dose-finding trial favoured 20 mg/day) |
| BNO 1095 fruit extract | Varies[3] | No human absorption data in our sources.[1] | No serious adverse events over three menstrual cycles.[3] | Moderate to severe PMS in Chinese women |
| Dried fruit, capsules or tinctures (unstandardized) | Varies[1][9] | No human absorption data in our sources.[1] | Nausea, stomach upset, headache and itching are the usual reported effects.[1][9] | Mostly unstandardized products; trial results with named extracts may not transfer |
Studied doses
Doses studied in human trials ranged from 8 to 30 mg/day of the Ze 440 extract, with 20 mg/day best supported, to a BNO 1095 extract corresponding to 40 mg of dried fruit, usually for three menstrual cycles; breast-pain trials typically used 20–40 mg/day for about 3 months.[3][4][7]
Interactions
Published interactions only: each row cites a source. No row means none was found in our sources, not that a combination is safe.
Medicines
- Dopamine-related medicinesReviewChasteberry constituents act on pituitary dopamine D2 receptors and shift prolactin. No human interaction studies were found, so combined effects with drugs acting on dopamine are unknown.[9]
- Hormone-sensitive conditions and their treatmentNIH fact sheetNCCIH advises that chasteberry may not be safe for women with hormone-sensitive conditions; no interaction studies with hormonal cancer drugs were found.[1]
Who should be careful
- Pregnancy
- NCCIH notes that chasteberry use during pregnancy may be unsafe, based on preclinical evidence.[1]
- Breastfeeding
- LactMed advises avoiding chasteberry while nursing because of safety concerns and possible suppression of milk supply.[9]
- Hormone-sensitive cancers
- NCCIH advises that chasteberry may not be safe for women with breast, uterine or ovarian cancer or other hormone-sensitive conditions.[1]
- Expecting menopause relief
- A Vitex and St John's wort combination was no better than placebo for hot flushes in a 16-week trial.[8]
Talk to your pharmacist or clinician before starting a supplement, especially if you take prescription medicines.
Safety
Short-term use looked well tolerated; avoid in pregnancy, breastfeeding and hormone-sensitive cancers.
- Side effects
- Usually mild: nausea, stomach pain, diarrhea, headache, itching, acne, rash and menstrual changes.[1][9]
- Duration studied
- Fruit extract has been used in research for up to 3 months; longer-term safety data are limited.[1]
- Liver
- LiverTox reports no link between oral chaste tree and liver enzyme rises or liver injury.[10]
- Prolactin
- Low doses raise prolactin and high doses may lower it, which is why LactMed flags possible effects on milk supply.[9]
How to read the label
- Label dose vs clinical dosePMS trials used named extracts: one Ze 440 tablet (20 mg/day in the dose-finding trial) or BNO 1095 equal to 40 mg of dried fruit. A label listing milligrams of raw fruit powder is not the same dose as milligrams of a concentrated extract.[2][3][4]
- More is not betterIn the dose-finding trial, 30 mg/day of Ze 440 gave no added benefit over 20 mg/day.[4]
- Products are not interchangeableLactMed notes that labelled and actual ingredients often differ, so results with one product may not apply to another.[9]
- Allow three menstrual cyclesThe positive PMS trials measured results at the end of the third menstrual cycle.[2][3]
Frequently asked questions
Does chasteberry help PMS?
Several trials of standardized extracts found more symptom relief than placebo, such as 52% vs 24% responders in a 2001 trial. Most trials are at high risk of bias, so the size of the benefit is uncertain.[2][6]
What dose was used in studies?
The dose-finding trial favoured 20 mg/day of the Ze 440 extract; 30 mg was no better. Breast-pain trials typically used 20–40 mg/day for about 3 months.[4][7]
Does chasteberry help menopause symptoms?
A 16-week trial of a Vitex and St John's wort combination found no difference from placebo for hot flushes. NCCIH says more research is needed.[8][1]
Can I use chasteberry while pregnant or breastfeeding?
NCCIH says it may be unsafe in pregnancy and breastfeeding, and LactMed advises avoiding it while nursing because it may reduce milk supply.[1][9]
Is chasteberry safe for the liver?
LiverTox has no reports linking oral chaste tree to liver enzyme rises or clinically apparent liver injury.[10]
Does chasteberry help breast pain?
A meta-analysis of 6 placebo-controlled trials (718 women) found a moderate benefit for cyclical breast pain, though most studies had unclear risk of bias.[7]
Sources
- [1]Chasteberry: Usefulness and Safety. NCCIH, 2025. fact-sheet
- [2]Treatment for the premenstrual syndrome with agnus castus fruit extract: prospective, randomised, placebo controlled study.. BMJ, 2001. RCT
- [3]Treatment for premenstrual syndrome with Vitex agnus castus: A prospective, randomized, multi-center placebo controlled study in China.. Maturitas, 2009. RCT
- [4]Dose-dependent efficacy of the Vitex agnus castus extract Ze 440 in patients suffering from premenstrual syndrome.. Phytomedicine, 2012. RCT
- [5]Vitex agnus-castus in premenstrual syndrome: A meta-analysis of double-blind randomised controlled trials.. Complement Ther Med, 2019. meta-analysis
- [6]The treatment of premenstrual syndrome with preparations of Vitex agnus castus: a systematic review and meta-analysis.. Am J Obstet Gynecol, 2017. meta-analysis
- [7]Vitex Agnus-Castus for the Treatment of Cyclic Mastalgia: A Systematic Review and Meta-Analysis.. J Womens Health (Larchmt), 2020. meta-analysis
- [8]Hypericum perforatum with Vitex agnus-castus in menopausal symptoms: a randomized, controlled trial.. Menopause, 2009. RCT
- [9]Chasteberry. Drugs and Lactation Database (LactMed).. NICHD, 2024. database
- [10]Chaste Tree. LiverTox: Clinical and Research Information on Drug-Induced Liver Injury.. NIDDK, 2023. database
What changed
- First draft (rebuilt after a lost earlier draft). Every PMID checked against NCBI E-utilities esummary (title and year) and the cited abstracts read; retraction/erratum check via PubMed CommentsCorrections found none for any cited PMID. Doses not given in an abstract are marked as not stated. No product links.
- Independent adversarial review (PR #201): spot-checked PMS trials, dose finding, both meta-analyses, mastalgia and menopause rows against PubMed abstracts. Summary safety line now attributed to NCCIH and LactMed instead of a direct instruction.