Vitex agnus-castus, commonly known as chaste tree or chasteberry, is traditionally used to support female reproductive health, specifically the ovaries and menstrual cycle. The use of Vitex dates back to ancient Greece and Rome, where it was employed for a variety of gynecological complaints. In modern times, its primary clinical applications include the management of premenstrual syndrome (PMS), premenstrual dysphoric disorder (PMDD), and mastalgia (cyclical breast pain), as well as supporting menstrual regularity.

Scientific studies suggest that Vitex may exert its effects by modulating pituitary function, specifically by decreasing prolactin levels through dopaminergic activity, which in turn can help normalize menstrual cycles. Several randomized controlled trials and systematic reviews have found that Vitex is more effective than placebo in alleviating symptoms of PMS and cyclical mastalgia. For example, a 2017 Cochrane review concluded that Vitex was superior to placebo for global symptom improvement in PMS, though methodological limitations and heterogeneity among studies were noted.

Evidence supporting its use for other ovarian-related conditions, such as polycystic ovary syndrome (PCOS) or direct ovarian function support, is less robust and primarily anecdotal or based on traditional use. Overall, while modern research validates traditional uses for certain menstrual disorders, more high-quality studies are needed to fully establish its efficacy and mechanisms related specifically to "ovarian support."