The Warnings

Vitex is generally well tolerated (Roemheld-Hamm, 2005). Adverse effects are considered rare, mild and reversible (Dugoua, Seely, Perri, Koren & Mills, 2008). The most common reported side effects include itching, rashes, headaches, nausea, dry mouth, acne, menstrual cycle changes and gastrointestinal complaints (Dugoua et al., 2008).  There was an isolated case of mild ovarian hyperstimulation in a woman who self-prescribed vitex (Blumenthal, 2003) and another case of nocturnal seizures (Dugoua et al., 2008). The patient in the latter case however, was taking vitex among other herbs and it was unlikely that vitex was the cause of the seizure.

There are no known drug interactions but because of its dopaminergic effects, it has been contraindicated with the use of dopamine-receptor blocking agents such as metoclopramide and dopamine-receptor antagonists such as haloperidol (Blumenthal, 2003). It has also been contraindicated in pregnancy due to its possible adverse effects in early fetal sexual development (Blumenthal, 2003) and in lactation due to its effect on breast milk possibly due to hormonal changes (“Vitex agnus-castus”, 2009). In addition, caution is recommended when using vitex with oral contraceptives and hormone-replacement therapy (Blumenthal, 2003). These views however, have not been substantiated by current scientific evidence (“Vitex agnus-castus”, 2009).