Vitex (Chasteberry) for PMS: A Few Good Trials, a Big Placebo Effect, and Hormone Claims It Hasn’t Earned

Vitex is the herb social media recommends for PMS, “hormone balance,” acne and fertility. The best PMS trials are real but few, all run on two branded extracts, and the wider literature is inflated by bias. Here is what the best studies found, what the doses were, and who should not take it.

By Kymata Health Editorial Published Last checked

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Nature's Answer Chasteberry Vitex Agnus-Castus, 90 Veg Caps

from HerbsPro

Label: 1 capsule: 200 mg chaste tree (Vitex agnus-castus) fruit extract plus 200 mg chaste tree fruit.

Best for trying one bottle: $12.74 one-time (checked Oct 15, 2026).

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How we chose: Momentous is the partner brand we list first, so its product leads whenever the Where to buy list has one for this compound or a form in our Forms table. Otherwise, among partner brands that passed our vetting without conditions (others only when none sells it), the first product in that list whose name matches a form in our Forms table, else the first one listed. Not a claim that it works: check the amount per serving against the studied doses and limits on our Chasteberry (Vitex) page.

Key takeaways

From 10 sources
  • In the best-known trial, 52% of women improved by at least half on a vitex extract versus 24% on placebo over 3 cycles; the extract’s maker sponsored the study1.
  • Pooling the 3 trials that described their extracts properly (520 women), vitex made symptom remission 2.57 times as likely as placebo4.
  • Placebo is strong in PMS: in a 208-woman trial, symptom scores fell 15.5 points on placebo and 22.7 points on vitex2.
  • A broader review of 14 trials found a large pooled effect but a high risk of bias and signs of publication bias, so the real benefit is probably smaller5.
  • NCCIH says vitex may be unsafe in pregnancy, while breastfeeding and with hormone-sensitive cancers, and that reliable evidence for fertility is lacking8.

Researched and written by Kymata Health Editorial; sources cited inline. Drawn from the studies cited below. Educational only, not medical advice.

What this article covers

1 evidence profile

The evidence, graded

Pulled from the trial tables in our evidence profiles. Grades follow our evidence-grading policy.

Graded findings

3 rows
  1. Grade BPMS symptom score and responder rateImproved 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.Chasteberry (Vitex) · RCT · n=170 · 2001 · PMID 11159568
  2. Grade BPMS remission (responder rate)Improved 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.Chasteberry (Vitex) · Meta-analysis · n=520 · 2019 · PMID 31780016
  3. Grade BCyclical breast painImproved 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.Chasteberry (Vitex) · Meta-analysis · n=718 · 2020 · PMID 31464546

What the strongest PMS trials found

Vitex agnus-castus is the dried fruit of the chaste tree, and most good trials used one of two standardized extracts, Ze 440 or BNO 10954. The trials below lasted three menstrual cycles and rated symptoms such as irritability, mood swings, anger, headache, breast fullness and bloating13.

  • Germany, 2001 (BMJ): 170 women with PMS took one Ze 440 tablet a day or placebo. Symptoms improved more on vitex, and 52% versus 24% had at least a 50% drop1. Mild side effects occurred in 4 women on vitex and 3 on placebo1. Zeller AG, which makes Ze 440, supplied the tablets and sponsored the study1.
  • China, 2009: 217 women with moderate to severe PMS were randomized to BNO 1095 (equal to 40 mg of dried fruit) or placebo, with 208 analysed2. The PMS diary score fell 22.7 points on vitex and 15.5 on placebo; no serious adverse events occurred2.
  • Dose finding, 2012: 162 women took 8, 20 or 30 mg of Ze 440 or placebo3. The 20 mg dose beat placebo and 8 mg, and 30 mg was no better than 20 mg3. Like the 2001 trial, it tested Zeller’s Ze 440 extract.

Why the true effect is probably smaller than it looks

PMS trials have a large placebo response. The authors of the Chinese trial reported a placebo effect of 50%2. That does not erase the extract’s edge, but it means many women who feel better on any pill would have felt better anyway.

A 2017 meta-analysis found 17 randomized trials, 14 of which could be pooled5. The pooled effect versus placebo was large (Hedges g −1.21), but heterogeneity was extreme (I² 91%), most trials had a high risk of bias, and funnel-plot tests suggested publication bias5. The authors called the pooled result exploratory and, at best, an overestimate5.

A stricter 2019 meta-analysis kept only double-blind trials that properly described the herbal product. Just 3 of 21 trials qualified, covering 520 women, and vitex still came out ahead: remission was 2.57 times as likely as on placebo (95% CI 1.52 to 4.35)4. That is the most defensible estimate, and it rests on three trials of two branded extracts.

Cyclical breast pain: moderate evidence

Breast tenderness before a period is the other use with real data. A 2020 review of 25 studies found vitex relieved cyclical breast pain and lowered raised prolactin in women aged 18 to 456. A conservative pooled analysis of 6 placebo-controlled trials (718 women) showed a moderate effect (SMD 0.67), though risk of bias was unclear in most studies6. Typical doses were 20 to 40 mg a day for 3 months6.

The likely mechanism is dopamine-like activity at the pituitary, which lowers prolactin6. That same action is why vitex is not a neutral herb, as the safety section explains.

Fertility, PCOS, acne and menopause: claims ahead of the data

Social media sells vitex as a general hormone balancer. The evidence does not stretch that far. NCCIH says there is not enough reliable evidence to know whether vitex helps sexual dysfunction or infertility, and notes it may be unsafe in pregnancy8.

For menopause, NCCIH notes one preliminary study suggesting possible help with some symptoms and says more research is needed8. A 16-week trial in 100 women gave a vitex and St John’s wort combination or placebo; hot flushes, menopause symptom scores and depression scores improved in both groups, with no significant difference between them7. Our menopause supplements review covers the products with better data.

For irregular cycles and PCOS, start with the diagnosis and the guideline-backed options; our PCOS hub covers both. We found no large placebo-controlled trial that supports vitex for PCOS or hormonal acne.

Safety: who should avoid vitex

NCCIH describes vitex as generally well tolerated in the short term, with fruit extract used safely in research for up to 3 months; side effects are usually mild, such as nausea, stomach pain, diarrhea, headache or itching8. LactMed adds acne, rash and menstrual changes to the list9. LiverTox reports that oral chaste tree has not been linked to liver enzyme rises or liver injury10.

  • Pregnancy: NCCIH says use during pregnancy may be unsafe8.
  • Breastfeeding: LactMed advises avoiding vitex while nursing because of safety concerns and possible suppression of milk supply; low doses raise prolactin, while high doses may lower it9.
  • Hormone-sensitive conditions: NCCIH says vitex may not be safe for women with breast, uterine or ovarian cancer or other hormone-sensitive conditions8.
  • Medicines that act on dopamine, such as some antipsychotics and Parkinson’s drugs: vitex constituents bind pituitary dopamine D2 receptors9, and we found no human interaction studies, so check with your prescriber.
  • Product choice: the positive trials used specific extracts (Ze 440 and BNO 1095), and the 2019 review excluded most trials because the product was poorly described4. A generic “vitex” capsule may not match what was studied; see our chasteberry page for the studied doses.

Quick answers

Common questions

4 answers
How long does vitex take to work for PMS?

The main trials measured results after three menstrual cycles12.

What dose of vitex was studied for PMS?

20 mg a day of the Ze 440 extract beat 8 mg and placebo, and 30 mg added nothing3. The BNO 1095 trial used an extract equal to 40 mg of dried fruit2.

Does vitex help with fertility or PCOS?

NCCIH says there is not enough reliable evidence to know whether it helps infertility, and that it may be unsafe in pregnancy8.

Can I take vitex while breastfeeding?

LactMed advises against it because of safety concerns and possible lower milk supply9.

Keep reading

Full evidence profiles

Every graded study, studied doses, interactions and safety

Related articles

4 articles

Browse the full Supplement & Nutrient Encyclopedia or all supplement articles.

Where to buy Chasteberry (Vitex)

Products from brands we partner with that contain Chasteberry (Vitex). Check the amount per serving against the doses studied, and the label for other ingredients.

Chasteberry (Vitex) products from partner brands

1 product
  • Quick pickHerbsProNature's Answer Chasteberry Vitex Agnus-Castus, 90 Veg Caps

    1 capsule: 200 mg chaste tree (Vitex agnus-castus) fruit extract plus 200 mg chaste tree fruit

    $12.74one-timeChecked Oct 15, 2026
    Shop at HerbsPro (paid link, opens in new tab)

Listing a product is not a claim that it works; check the amount per serving against the doses studied, and the label for other ingredients.Prices and labels are from each brand’s own site on the date shown; confirm before you buy.

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References

10 sources. Numbers in the text link here.

Sources cited in this article

10 sources
  1. 1Treatment for the premenstrual syndrome with agnus castus fruit extract: prospective, randomised, placebo controlled studyBMJ, 2001 · PMID 11159568
  2. 2Treatment for premenstrual syndrome with Vitex agnus castus: A prospective, randomized, multi-center placebo controlled study in ChinaMaturitas, 2009 · PMID 19269753
  3. 3Dose-dependent efficacy of the Vitex agnus castus extract Ze 440 in patients suffering from premenstrual syndromePhytomedicine, 2012 · PMID 23022391
  4. 4Vitex agnus-castus in premenstrual syndrome: A meta-analysis of double-blind randomised controlled trialsComplement Ther Med, 2019 · PMID 31780016
  5. 5The treatment of premenstrual syndrome with preparations of Vitex agnus castus: a systematic review and meta-analysisAm J Obstet Gynecol, 2017 · PMID 28237870
  6. 6Vitex Agnus-Castus for the Treatment of Cyclic Mastalgia: A Systematic Review and Meta-AnalysisJ Womens Health (Larchmt), 2020 · PMID 31464546
  7. 7Hypericum perforatum with Vitex agnus-castus in menopausal symptoms: a randomized, controlled trialMenopause, 2009 · PMID 18791483
  8. 8Chasteberry: Usefulness and SafetyNCCIH, 2025
  9. 9Chasteberry. Drugs and Lactation Database (LactMed)NICHD, 2024 · PMID 30000866
  10. 10Chaste Tree. LiverTox: Clinical and Research Information on Drug-Induced Liver InjuryNIDDK, 2023 · PMID 36745730

Chasteberry (Vitex) and other dietary supplements are not intended to diagnose, treat, cure or prevent any disease, and these statements have not been evaluated by the FDA. Talk to your clinician or pharmacist before starting a supplement, especially if you take prescription medicines. Product links on this page are paid partner links.

Educational only. Not medical advice. Some links earn us a commission: kymatahealth.com/affiliate-disclosure.