

Chaste tree fruit, monk's pepper
Derived from the fruit of the tree, chasteberry contains steroidal precursors and active moieties including progesterone, testosterone, and androstenedione. It was shown to have antiproliferative (13) and hepatoprotective (14) properties in vitro. Several clinical studies in women suggest its efficacy in reducing symptoms associated with PMS (8) (9), and for the treatment of mastalgia (15).
Chasteberry may interact with oral contraceptives, hormonal therapy, and dopamine antagonists (such as haloperidol and prochlorperazine) (5). It also demonstrated estrogenic activity (11) (12) and should be avoided by patients with hormone-sensitive disease.
Chasteberry may exert opioidergic effects through the activation of mu opioid receptors (MOR) and delta opioid receptors (DOR), but not kappa opioid receptors (KOR) (9). In animal studies, chasteberry has been reported to diminish release of follicle-stimulating hormone from the anterior pituitary while increasing the release of luteinizing hormone and prolactin. It also contains constituents that bind to dopamine (d1 and d2) receptors and seem to inhibit prolactin release (10). In vitro studies, constituents isolated from chasteberry can stimulate estrogen receptors (7) (8). In human studies, it has been found to restore progesterone concentrations, prolong the hyperthermic phase in the basal temperature curve, and restore the LH-RH test to normal. It is thought to act on the pituitary-hypothalamic axis rather than directly on the ovaries (11) (4).
Oral Contraceptives: Theoretically, Chasteberry may interfere with efficacy due to its hormone-regulating activity.
Dopamine D2-Antagonists: Theoretically, chasteberry may interfere with the action of drugs that antagonize dopamine receptors (e.g. chlorpromazine, haloperidol, prochlorperazine).(5)
Schellenberg R. Treatment for the premenstrual syndrome with agnus castus fruit extract: prospective, randomized, placebo controlled study over three menstrual cycles. BMJ 2001;322:134-7.
A double-blind, placebo-controlled study of 178 women found that treatment with chasteberry over three menstrual cycles significantly reduced PMS symptoms. Responder rates were 52% and 24% for active and placebo, respectively. The dose used was one tablet of chasteberry dry extract three times a day. Women in the treatment group experienced significant improvements in symptoms, including depression, headache, irritability, and breast tenderness.
Loch EG, Selle H, Boblitz N. Treatment of premenstrual syndrome with a phytopharmaceutical formulation containing vitex agnus castus. J Womens Health Gend Based Med 2000;9:315-20.
A non-interventional review of 1,634 female German patients suffering from PMS who were treated with a vitex preparation. Questionnaires, completed by the physician at baseline and after three menstrual cycles, evaluated the symptoms of PMS and efficacy of herbal supplement. Results indicate that a reduction in PMS symptoms including depression, anxiety, bloating, and headache occurred. Reported adverse events included 13 cases of skin symptoms (pruritus, rash, eczema, hair loss) and 6 reports of mild gastrointestinal complaints (nausea, vomiting, diarrhea, stomach pain).
Bottom Line: There is evidence to suggest that chasteberry helps improve symptoms associated with premenstrual syndrome.
Chasteberry is a fruit extract. Laboratory analysis has shown that chasteberry contains active hormones that are also produced by the human body, such as progesterone, testosterone, and androstenedione. In studies in both laboratory animals and humans, chasteberry has been found to alter the release of gonadotropins (hormones that stimulate secretion of sex hormones from the ovaries and testes) from the pituitary gland in the brain. It is hypothesized that this has a downstream effect on the release of sex hormones (estrogen, progesterone, and testosterone) within the body, but scientists are unsure exactly how chasteberry works.
Premenstrual syndrome (PMS):
A randomized controlled trial studied whether chasteberry could relieve premenstrual symptoms in 178 women. For three menstrual cycles, 86 women took one chasteberry extract tablet three times daily, while 84 women took three placebo pills daily. Compared to women taking the placebo, women taking chasteberry reported significant reductions in PMS symptoms, including depression, headache, irritability, and breast tenderness. 24% of the placebo group and 52% of the chasteberry group reported such improvements.
Researchers followed 1,634 female German patients who were taking a chasteberry extract to treat premenstrual symptoms. After three months of taking the extract, 93% of patients reported a decrease in the number of symptoms, including depression, anxiety, craving, and bloating. Some women reported an end of PMS complaints altogether. However, this study lacks a control group (a group taking a placebo pill) to which the researchers could compare their results with chasteberry. About 1% of women had side effects, including itching, rash, eczema, hair loss, and gastrointestinal complaints.
Reported: The most frequent adverse events are nausea, headache, gastrointestinal disturbances, menstrual disorders, acne, pruritus and erythematous rash.
Scientists are unsure of the effects of long-term use of herbs that contain sex hormones, such as chasteberry.