Premenstrual syndrome (PMS) is a complex combination of a variety of symptoms including mood swings, anxiety, depression, tender breasts and food cravings. For some women the physical pain and emotional stress are severe enough to affect their daily routines and activities. The causes of the premenstrual syndrome have not yet been understood clearly, but have been attributed to hormonal and neuronal dysbalance, diet and lifestyle. Hyperprolactinemia seems to be an important factor which is considered to be part of the endocrine disorder. Different clinical investigations and double blind trials have shown that preparations containing Vitex agnus castus fruit extract are a useful tool to decrease pathophysiologicaly increased prolactin serum levels and though could be an effective treatment for women suffering from premenstrual syndrome.