The treatment of premenstrual syndrome with preparations of Vitex agnus castus: a systematic review and meta-analysis

Although meta-analysis shows a large pooled effect of Vitex agnus castus in placebo-controlled trials, the high risk of bias, high heterogeneity, and risk of publication bias of the included studies preclude a definitive conclusion. The pooled treatment effects should be viewed as merely explorative and, at best, overestimating the real treatment effect of Vitex agnus castus for premenstrual syndrome symptoms. There is a clear need for high-quality trials of appropriate size examining the effect of standardized extracts of Vitex agnus castus in comparison to placebo, selective serotonin reuptake inhibitors, and oral contraceptives to establish relative efficacy.