Chaste tree (Vitex agnus-castus), also known as chasteberry, has a long history of use in traditional herbal medicine, particularly within European and Mediterranean cultures, for various gynecological conditions. One of its primary traditional uses is to help regulate menstrual cycles, especially in cases of scanty menstruation (oligomenorrhea or hypomenorrhea). Ancient Greek and Roman sources mention the use of chaste tree for female reproductive health, and it was believed to support hormonal balance by acting on the pituitary gland to modulate prolactin levels. In folk medicine, it was often prescribed to women experiencing irregular or insufficient menstrual flow, with the aim of promoting a more regular and robust cycle.

While there is some modern clinical evidence supporting the use of chaste tree for premenstrual syndrome (PMS), mastalgia (breast pain), and certain menstrual irregularities, the scientific validation specifically for scant menstruation is limited. Most clinical studies have focused on conditions like luteal phase defects and PMS rather than low menstrual volume. However, the traditional rationale suggests that by influencing prolactin and possibly other reproductive hormones, chaste tree might indirectly encourage normal menstrual flow in women with hormonal imbalances. Overall, its use for scant menstruation is primarily supported by tradition and historical use, with moderate evidence from clinical experience and observational studies, but only limited direct clinical research for this specific indication.