GradedHealth

Does chasteberry help PMS symptoms?

Trials suggest chasteberry extract may ease PMS symptoms more than placebo. The studies are small, and it is best avoided in pregnancy.

Published October 2026

Short answer

Chasteberry extract may ease PMS symptoms: several placebo-controlled trials found more relief than placebo, but the studies are small and varied. Evidence grade C (Limited). Several placebo-controlled trials and meta-analyses; downgraded for inconsistency between studies and high risk of bias.

Key takeaways

  • In a 2019 meta-analysis of three placebo-controlled trials (520 women), chasteberry extract made women about 2.6 times as likely to see their PMS symptoms go into remission as placebo [1].
  • A 2017 meta-analysis of 14 trials found a large average effect, but most trials were at high risk of bias and the results varied widely, so the authors judged the pooled figure likely overstated [2].
  • The main side effects in the reviewed studies were mild and reversible, such as nausea, headache and stomach upset [3].
  • Reviews advise avoiding chasteberry during pregnancy or breastfeeding, because human evidence on safety is poor [3][4].

The short version

Chasteberry extract may ease premenstrual syndrome (PMS) symptoms more than placebo does, according to several placebo-controlled trials and reviews [1][2]. The studies are small and differ from one another, so the size of the benefit is uncertain. Reviews advise avoiding it during pregnancy or breastfeeding [3].

What the studies show

A 2019 meta-analysis pooled three double-blind, placebo-controlled trials of 520 women. Women taking chasteberry were about 2.6 times as likely to see their symptoms go into remission as those on placebo [1].

A 2017 meta-analysis of 14 trials found a large average effect. The authors noted that most trials had a high risk of bias and that results varied widely, so they judged the pooled effect likely overstated [2].

In one trial of 67 Chinese women, the symptom score fell from 29.4 to 4.3 with a chasteberry tablet (BNO 1095) and from 28.8 to 11.8 with placebo over three cycles [5]. Symptoms were tracked in a daily diary.

A trial of 162 women found that 20 mg a day of the Ze 440 extract eased symptoms more than placebo and more than 8 mg. The 30 mg dose was no better than 20 mg [6].

The nuances

Most trials used standardised extracts, such as Ze 440 and BNO 1095, rather than teas or home-made preparations. Results do not carry over between products, and reviews say differences in preparation make trials hard to compare [7].

For severe PMS (premenstrual dysphoric disorder), the evidence is thinner. Two trials compared chasteberry with fluoxetine, an antidepressant. One found them about equal, and the other found fluoxetine worked better [8].

A pilot trial of PREMEN-CALM, a supplement that combines chasteberry with other ingredients, found no difference between the active and placebo groups in 42 women [9].

A 2024 real-world study of 1,700 women reported large drops in irregular cycles and breast tenderness, but it had no placebo group, and several authors are employees of Bionorica SE [10].

The most common side effects are mild and reversible: nausea, headache, stomach upset, changes in periods, acne, itching and rash [3]. The safety review reported no drug interactions, but it noted a theoretical risk with medicines that block dopamine [3]. Reviews advise avoiding chasteberry during pregnancy or breastfeeding, because human evidence is poor [3][4]. In rats, an extract changed pregnancy and fetal outcomes, which does not tell us what happens in people [11]. Our searches found no human studies on liver injury or upper limits, so the full list of cautions is on the chasteberry topic page.

What this means for you

Chasteberry is one of the herbs with the most trial data for PMS [12]. The evidence is promising but limited, so the effect for any one woman is hard to predict. Talk with a doctor before trying it, especially if you are pregnant, breastfeeding, or take other medicines.

Go deeper

  • Chasteberry — Standardised chasteberry extracts have been tested in several placebo-controlled trials, and reviews suggest they ease PMS symptoms more than placebo.

References

  1. Vitex agnus-castus in premenstrual syndrome: A meta-analysis of double-blind randomised controlled trials.. Complement Ther Med, 2019.
  2. The treatment of premenstrual syndrome with preparations of Vitex agnus castus: a systematic review and meta-analysis.. Am J Obstet Gynecol, 2017.
  3. Vitex agnus castus: a systematic review of adverse events.. Drug Saf, 2005.
  4. Safety and efficacy of chastetree (Vitex agnus-castus) during pregnancy and lactation.. Can J Clin Pharmacol, 2008.
  5. Treatment of moderate to severe premenstrual syndrome with Vitex agnus castus (BNO 1095) in Chinese women.. Gynecol Endocrinol, 2010.
  6. Dose-dependent efficacy of the Vitex agnus castus extract Ze 440 in patients suffering from premenstrual syndrome.. Phytomedicine, 2012.
  7. Vitex agnus castus for premenstrual syndrome and premenstrual dysphoric disorder: a systematic review.. Arch Womens Ment Health, 2017.
  8. Vitex agnus-castus extracts for female reproductive disorders: a systematic review of clinical trials.. Planta Med, 2013.
  9. Effects of the PREMEN-CALM® in the Management of the Premenstrual Syndrome: A Randomized, Double-Blind, Placebo-Controlled Pilot Study.. J Diet Suppl, 2024.
  10. Use of Vitex agnus-castus in patients with menstrual cycle disorders: a single-center retrospective longitudinal cohort study.. Arch Gynecol Obstet, 2024.
  11. Does Vitex Agnus-Castus L. Have Deleterious Effect on Fertility and Pregnancy Outcome? An Experimental Study on Rats for Prediction of Its Safety.. J Pharmacopuncture, 2022.
  12. Herbal treatments for alleviating premenstrual symptoms: a systematic review.. J Psychosom Obstet Gynaecol, 2011.