The prolactin-inhibiting effect of Vitex agnus castus preparations, which results from dopaminergic activities, has been shown in humans and gives a pharmacological rationale for its clinical effects. Confirmation of efficacy in the treatment of mastalgia has been provided by two recent double-blind studies conducted according to the principles of Good Clinical Practice. One double-blind study, several open and post-marketing surveillance studies have shown that the premenstrual syndrome, or individual symptoms, can be influenced positively. Design shortcomings in a second double-blind study should be eliminated in future studies of this indication to improve the body of evidence. Hitherto, there has been one controlled double-blind study of cycle disorders in the case of corpus luteum insufficiency with significant results and a number of uncontrolled open studies. The high success rates in the open studies indicate therapeutic effects, and it should be possible to reproduce these results under double-blind conditions. The success rates on fertility disorders should be confirmed in controlled double-blind studies.