Agnus Castus for Menstrual Health

Research suggests that Vitex agnus-castus (chaste tree berry) may offer benefits for several aspects of menstrual health, including premenstrual syndrome, menstrual irregularities, breast pain, and elevated prolactin levels, with evidence drawn from a combination of randomized controlled trials, meta-analyses, retrospective studies, and narrative reviews spanning several decades. Studies indicate that a 2017 meta-analysis pooling 17 randomized controlled trials found a large positive effect on PMS symptoms, though the authors flagged high risk of bias, inconsistent results across trials, and signs of publication bias as serious reasons to interpret this finding cautiously, and a 2024 retrospective study of 1,700 women reported meaningful real-world improvements in cycle regularity, pain, and breast tenderness with few safety concerns. However, the evidence is notably mixed in some areas — a 2019 meta-analysis found that Vitex did not significantly reduce menstrual blood loss compared to placebo and appeared to perform less well than mefenamic acid for heavy periods, a 2023 review on prolactin-lowering effects concluded that available studies are too small and inconsistent for firm conclusions, and a 2006 review raised concerns about dose-dependent hormonal effects and advised against use during breastfeeding. Across nearly all study types, researchers consistently emphasize that while the preliminary evidence is promising, the overall body of research is limited by small sample sizes, variable study quality, and a lack of standardized extracts, meaning larger and more rigorous clinical trials are still needed before definitive conclusions about effectiveness can be drawn.