Chasteberry Chasteberry (Vitex agnus-castus) is a botanical with a long history of use for “menstrual disorders.” Many small studies have shown promising results, and one larger study examined the effectiveness of chasteberry on PMDD (34,35). In this randomized controlled trial, the active arm received 20 mg of chasteberry daily. Compared with placebo, the patients receiving chasteberry had a significant improvement in the combined symptom score (35). A multicenter noninterventional trial examined the experience and tolerance of chasteberry in 1,634 patients. After use in three cycles, 93% of women reported a decrease in or cessation of symptoms, and 94% of patients reported good or very good tolerance to this botanical. Adverse drug reactions were suspected by physicians in 1.2% of patients, but there were no serious adverse reactions (36). A randomized, single-blind trial comparing Vitex and ﬂuoxetine showed equal symptom reduction at 2 months (58% and 68%, respectively) (37). In both arms, there were significantly improved symptoms. Two of the three randomized controlled trials evaluating chasteberry for PMS showed some benefit on symptoms such as irritability, mood swings, anger, breast tenderness, and headaches. In the study with no benefit, the placebo arm was a soy-based product, which may reduce symptoms of PMS. Because chasteberry contains iridoids and ﬂavonoids, the mechanism of action is believed to be stimulation of dopamine D2 receptors, which decrease prolactin levels. In vitro, it inhibits opioid, mu, and kappa receptors. It has no effect on luteinizing hormone or follicle-stimulating hormone levels (38). Vitex restores progesterone levels and in Germany is used to treat menstrual irregularities and undiagnosed infertility. No significant toxicities were reported with Vitex extracts when used in appropriate dosages.
St. John’s Wort St. John’s wort (Hypericum perforatum) is recognized as an effective antidepressant for the treatment of mild to moderate depression. One open trial of 19 women found that this compound, when used at a dose of 300 mg per day of a 0.3% hypericin standardized extract, showed a 51% improvement in mood disturbances in PMS/PMDD (39). This dose is one-third of that typically used for depression. The most recent randomized controlled trial showed a “nonsignificant trend for SJW to be superior to placebo.” This trial did not use a product that contains both active ingredients, namely hypericin and hyperforin (22). Although adverse reactions occur less frequently than with prescription antidepressants, care must be exercised with the use of this product. Most common side effects include gastrointestinal upset, headache, and agitation. Rare but severe phototoxicity was reported. Because St. John’s wort induces the cytochrome P450 complex, significant drug interactions can occur. Specifically, reduced levels of birth control pills, theophylline, cyclosporine, and antiretroviral drugs were reported. Interactions were described with buspirone, statins, calcium channel blockers, digoxin, and carbamazepine. There are no apparent significant interactions with Coumadin. The mechanism of action for its efficacy in the treatment of PMS is not elucidated. There were two isolated reports of pregnancy occurring in women who were taking oral contraceptives in conjunction with St. John’s wort. If patients choose to take St. John’s wort, they may want to use a backup method of birth control or change to a different method.