Q&A

Is an extract of the fruit of agnus castus (chaste tree or chasteberry) effective for prevention of symptoms of premenstrual syndrome (PMS)?

Author and Disclosure Information

Schellenberg R. Treatment for the premenstrual syndrome with agnus castus fruit extract: prospective, randomised, placebo controlled study. BMJ 2001; 322:134-37.


 

BACKGROUND: PMS is both common and troublesome, and there is no consensus on the most tolerable and effective therapy. Chasteberry fruit is commonly used in Europe for this condition. Given the strong placebo response noted with PMS1 and the increasing popularity and availability of herbal formulations in the United States, carefully controlled trials are needed to assess these new treatment options.

POPULATION STUDIED: Six general medicine outpatient clinics in Germany recruited 178 women aged 18 years or older with PMS as defined by the Diagnostic and Statistical Manual of Mental Disorders, third edition, revised. Exclusion criteria included psychotherapy, any serious medical condition, pregnancy, breast-feeding, inadequate contraception, alcohol or drug dependence, hypersensitivity to chasteberry, fever, pituitary disease, or use of sex hormones other than oral contraceptives. The treatment groups did not differ significantly in terms of age (mean=36 years), weight, cycle characteristics, or initial assessments of severity.

STUDY DESIGN AND VALIDITY: In this prospective randomized double-blind placebo-controlled trial, participants received either a chasteberry (ZE 440) 20-mg tablet standardized for casticin (one of the presumed active principles) or matching placebo once daily. The authors assessed efficacy by comparing validated self-assessment scales at baseline (beginning of first menstrual cycle) and at the end of the third cycle. Tolerability was assessed using side effects reported at the last study visit, rather than by recording in a daily diary.

OUTCOMES MEASURED: The primary outcome was the change from baseline to end point in a combined score of 6 self-assessment items rated on a visual analog scale (irritability, mood alteration, anger, headache, other menstrual symptoms including bloating, and breast fullness). The secondary outcomes included each of the 6 items independently, 3 global assessment items (corroborated by physicians), and the responder rate, defined as 50% or more reduction in self-assessed symptoms from baseline.

RESULTS: Compared with placebo, patients who received chasteberry had a significant improvement in the combined symptom score (P <.001). In 5 of the 6 self-assessment items (irritability, mood alteration, anger, headache, and breast fullness), chasteberry was more effective than placebo (P <.01), with “other symptoms including bloating” being unaffected by treatment. All 3 global assessment items significantly favored the treated group, as did the responder rate (52% vs 24%, no statistical analysis presented). These results remained unchanged by subgroup analyses that excluded women taking oral contraceptives and included the 8 women initially screened but without postbaseline values who were removed from the initial intention-to-treat population. Side effect rates were similar in the 2 groups; all were mild, and none led to discontinuation.

RECOMMENDATIONS FOR CLINICAL PRACTICE

The formulation of chasteberry used in this appropriately designed study was well tolerated and more effective than placebo in decreasing symptoms of PMS. Most symptoms of PMS significantly improved with active treatment, and slightly more than half the women taking this herb experienced a substantial (>50%) decrease in overall symptoms. Because of reduced Food and Drug Administration oversight of the manufacturing of herbal medicines in the United States, we cannot be certain that our patients have access to chasteberry extract similar to the one used in this study. If such a product can be found, it can be recommended as one of the initial treatments for this common and troublesome condition.

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