Chaste Tree Berry (Vitex Agnus-Castus)

Medical Uses

Chaste tree berries are used for premenstrual syndrome and for menopausal and menstrual symptoms.

Historical Uses

Long associated with chastity and virtue, this herb is also known as “monk’s pepper” and chasteberry In folklore, chaste tree berry was used for menstrual problems and to increase milk flow


Chaste trees grow in the southern United States. The berries look and smell like peppercorns.

Chaste Tree Berry: Part Used

• Fruit

Major Active Compounds

• Flavonoids

• Agnuside

Chaste Tree Berry: Clinical Uses

Chaste tree berry is used for premenstrual syndrome and for menopausal and menstrual symptoms. It is approved by the German Commission E for “menstrual irregularities, PMS, and mastodynia” (breast tenderness).

Mechanism of Action

Chaste tree berries work to balance progesterone and estrogen and decrease prolactin levels. They have shown significant competitive binding to estrogen receptors alpha and beta and have stimulated a progesterone receptor.

Chaste Tree Berry: Dosage

Tea: Pour 1 cup of boiling water onto 1 teaspoon (0.5 to 1 g) of ripe berries and let sit for 10 to 15 minutes. The tea may be taken up to three times a day.

Standardized vitex extract: 40 drops once a day. Standardized to 0.6 percent agnuside.

Tincture: May be taken at 40 drops three times a day. Studies used 20 to 40 mg of dried berry extract standardized to contain 0.5 percent agnuside. Chaste tree berry maybe taken for 6 months to a year.

Capsules: Because each brand differs in amount, capsules should be taken as directed.

Side Effects

Side effects may include itching, gastrointestinal complaints, and headache.


• This herb is contraindicated during pregnancy and breast-feeding.

Herb-Drug Interactions

In animal studies, chaste tree berry had a dopaminergic effect. Therefore caution is warranted during use with dopamine-receptor antagonists (i.e., haloperidol). Caution is also warranted during use with metoclopramide, hormone therapy, or oral contraceptives because the herb may counteract their effects.

Pregnancy and Breast-Feeding

Do not use chaste tree berry in pregnant women because it has uterine stimulant properties. Also avoid use in breast-feeding women.

Pediatric Patients

This herb is not used in children.

Summary of Studies

Loch et al. (2000). This open, uncontrolled study took place over 3 months and included 1634 women with premenstrual syndrome. Results: Patients reported a decrease in the number of symptoms and even cessation of premenstrual complaints, with good tolerability

Klepser & Nisly (1999). Several studies concluded that women had a significant reduction in premenstrual syndrome symptoms. Efficacy in physician reports exceeded 90 percent, and 57 percent of patients reported improvement in their symptoms.

Lauritzen et al. (1997). A controlled, randomized, double-blind study of 175 women over a 3-month period compared the use of vitex and pyridoxine for premenstrual syndrome. Vitex capsules contained 3.5 to 4.2 mg dried chaste tree berry extract. Product: Agnolyt of Germany, plus one placebo capsule (n=90),or two 100-mg capsules of pyridoxine (n=85). Results: Vitex improved and alleviated symptoms of premenstrual syndrome better than pyridoxine did. Both groups reported mild side effects including headache, gastrointestinal and abdominal complaints, and skin problems.

Schellenberg (2001). A study of 178 women given chaste tree berry or placebo in doses of one tablet daily for three consecutive cycles showed that chaste tree berry was effective and well tolerated for relief of the symptoms of premenstrual tension.

Chaste Tree Berry: Warnings

• Side effects may include itching, gastrointestinal complaints, and headache.

• Discuss use of this herb with your health-care practitioner if you take any of the following medications: haloperidol, metoclopramide, hormone therapy, or oral contraceptives.

• Don’t use this herb during pregnancy or breast-feeding.

• This herb is not recommended for children.