Vitex agnus castus (The Chaste Tree or Chasteberry or Monk’s Pepper ) is a popular treatment for the management of female reproductive disorders including corpus luteum insufficiency, premenstrual syndrome (PMS),menopausal symptoms, and insufficient milk production. The German Commission E recommends it for menstrual problems, mastalgia, and premenstrual syndrome.
The specific chemical components responsible for its clinical effects have not been determined. One proposed mechanism is an effect on the pituitary’s release of prolactin. Small randomized controlled trials indicate that vitex may be helpful in hyperprolactinemia, PMS and cyclical breast pain.
For centuries, chasteberry has been used to treat many hormone-related gynecologic conditions. The current literature supports the use of chasteberry for cyclical breast discomfort and premenstrual syndrome; data on its use for menstrual irregularities and fertility disorders are weak. Its traditional use as a galactagogue is not well supported in the literature and should be discouraged. There are no clinical data to support the use of chasteberry for reducing sexual desire, which has been a traditional application. Chasteberry is well tolerated; reported adverse effects are minor and may include gastrointestinal complaints, dizziness, and dry mouth.
No herb-drug interactions have been reported, but caution is advised for its concomitant use with dopamine agonists or antagonists. Optimal standardization and dosing recommendations await clarification in clinical studies.
Further research is needed to access its efficacy and safety for use by lactating mothers. There are no studies of its effects on menopausal symptoms or its safety in pregnancy. Side effects are rare and include rash, GI disorders, headache and increased menstrual flow.
Clinical studies have shown its beneficial effects in the management of premenstrual stress syndrome (PMS). The use of extracts of the plant is recommended in Germany. One randomized placebo controlled study has shown that Vitex agnus castus is an effective treatment for women with PMS. The effects were confirmed by the women’s self-assessment and by the investigators’ evaluation. Tolerability of agnus castus was good; patient acceptance was high and side-effects were few and mild.
Its mechanism of action is not well known. A study has found that treatment with Vitex Agnus-castus caused a slight reduction of prolactin levels. A decrease of prolactin will influence levels of follicle-stimulating hormone (FSH) and estrogen in women; and testosterone in men.