Materia Medica

Vitex agnus-castus L.  Verbenaceae.  The common name is chasteberry and chaste tree

Vitex is native to Greece and Italy, and it has a long history of folk use in those regions.  The Greeks named it agnus castus from agnos castus, meaning “chaste” because they believed that it calmed the sexual passions.  This reputation followed it through the ages and it was used by both priests and nuns at various time periods to help subdue passions.  There were questions about the efficiency of this remedy and it passed in and out of popularity a number of times.  Other uses for it through the ages included digestive problems, headaches, epilepsy, inflammation of the uterus, emmenogogue and galactogogue.

A patent medicine of an extract of Vitex, called Agnolyt, has been produced in Germany since the 1930s.  Many of the studies done on Vitex are done with this product.

Vitex is shrub that it native to the Mediterranean, but it is now common in the United States.  It has willow like leaves and spires of lilac flowers, which bloom in summer.  The fruits that follow are blackish and about the size of a peppercorn also have a pepperish aroma and flavor.  It is in the Verbanaceae family that consists of about 60 species.

The berry is the most common part of the plant used.  There is some folk usage of the leaves.  It is available as bulk herb, capsule, and hydroalcoholic extracts, and is often mixed with other herbs.

The specific active ingredients of Vitex have not been individually isolated and so all studies have been done with the whole fruit.  The main action is on the hypothalamus and pituitary, it has a regulatory effect on the pituitary.  It increases lutenizing hormone (LH) and inhibits the release of follicle stimulating hormone (FSH).  This creates a corpus luteum like hormone effect, shifting the ratio of estrogen and progesterone to the favor of progesterone.¹  Vitex is able to modulate progesterone levels in the body without direct hormonal action, in contrast to many of the herbal regulators that have phytoestrogens.

Vitex has also been found to modulate prolactin levels in both men and rats, stimulating prolactin at low doses and decreasing it at high levels.²  This is probably from its ability to bind dopamine receptors,³ which subsequently inhibit prolaction release by the pituitary.  This points to its possible usefulness in hyperprolactinemia.  Vitex has also been shown to be useful to increase milk production in lactating women.⁴

The German Commission E recommends Vitex for irregularities of the menstrual cycle, premenstrual complaints and mastodynia.⁵

Vitex is popularly used for the treatment of  premenstrual syndrome, as well as other menstrual symptoms such as heavy bleeding and too short a cycle.  It has found particular favor in recent years for menopausal symptoms.  Vitex is also taken for uterine fibroids, to increase lactation and for teenage acne of both sexes.

The fruit contains about 0.5 to 1.22% essential oil which includes cineol, alpha- and beta-pinene, linonene and sabinene.  There are two iridoid glycosides that have been isolated, agnuside and aucubin.  Agnuside is used as a reference for quality control.  Flavonoids, including castican, orientin and isovitexin, and fixed fatty acids are also present in the fruit.⁶⁷

The average dose is 40 drops of the hydroalcoholic extract, taken once a day, a half-hour before breakfast.  The equivalent dose in capsules is about 3-4 capsules.  Vitex probably starts working in about ten days, but for full benefit should be taken for at least six months and up to a year and a half.⁸  There should be a noticeable improvement by the second menstrual cycle when used for PMS.  Be patient, it takes ten days to two months to see results, and should be continued for at least six months..

Do not take during pregnancy.  Occasional itching, rashes and gastrointestinal upset have been reported.  There is one reported case of ovarian hyperstimulation syndrome in the luteal phase.⁹  The effect of Vitex is blocked by dopamine receptor blocking agents such haloperidol.  There is a possibility for interactions with oral contraceptives, hormone replacement therapy or other sex hormones.