Dr. Tori Hudson, N.D.

Premenstrual syndrome (PMS) is one of the most common cyclic menstrual related problems reproductive age women experience.  For most it is mild, but for some it is moderate to even severe (5-8%).  Symptoms occur in the luteal phase of the menstrual cycle – starting anywhere from ovulation to right before the menses, and then cease with onset of menses or during menses or right after menses is over.  Symptoms can include headache, edema, breast tenderness/pain, abdominal discomfort/bloating, anxiety, depression, agitation, and aggression.  Some women have a special version of PMS called premenstrual dysphoric disorder (PMDD), which is more severe, and includes one or more of the mood aspects of PMS.
The most commonly accepted hypothesis as to the cause of PMS and PMDD is the influence of the hormonal changes on serotonin.  In fact, the most common pharmaceutical treatment prescribed is selective serotonin reuptake inhibitors (SSRIs), but these can come with undesirable side effects.  There are numerous published studies on natural agents for PMS including vitamin B6, calcium, St. John’s wort, evening primrose oil, vitamin E, tryptophan, multiple vitamin-mineral and chaste tree.   Chaste tree, aka Vitex agnus-castus is well published in terms of cyclic menstrual related symptoms.  The goal of the current systematic review and meta-analysis was to determine the effectiveness and tolerance of chaste tree in the treatment of PMS and/or PMDD. 
  Ten databases were searched and updated as of January 2016.  Included studies were randomized controlled trials that used a preparation of chaste tree although not all studies used the same dose or preparation; and the herbal group was compared to either a placebo or pharmacological or other natural agent for a minimum of two menstrual cycles.   No studies of homeopathic preparations of chaste tree were included. 
In the final search and analysis, seventeen randomized controlled trials were included in the qualitative analysis and 14 of those were also included in the quantitative analysis; there was insufficient data for the other three.  Ten studies were placebo controlled and nine were other agent controlled, including SSRI, fluoxetine, an oral contraceptive, vitamin B6, magnesium, St. John’s wort or vitamin E. Two of the trials compared chaste tree to both an oral contraceptive and a placebo.  Most studies were double-blind but two were single blind and blinding was not clear in the two others. 
In 10 of the studies that used a placebo control, chaste tree was found to be superior in nine of them.  These 9 used an extract and the one negative study used ground berries.   Chaste tree was superior for relieving PMS symptoms in all the studies comparing it to any of the other natural agents.  Chaste tree was comparable to oral contraceptives in the studies where this was compared.   Chaste tree was comparable to fluoxetine in one study but in another, some components of the Hamilton depression rating scale scored higher for fluoxetine.   Fewer side effects occurred in the women on chaste tree vs. fluoxetine or the oral contraceptives. 
Commentary:  The results of this meta-analysis demonstrates a clear efficacy of chaste tree extracts for PMS/PMDD.  Although all the studies compared were not the same in dosages and preparations, and some of the studies suggested possible bias or exclusion of important data, the positive results in especially the double-blinded studies is definitely a positive for chaste tree.  It also appears that studies using standardized extracts of chaste tree are superior in both results and study formats. 
I’ve long used chaste tree berry extracts as a main stay in my treatment plans for women with PMS/PMDD, but I rarely use it alone, and feel very comfortable and even better using it with St John’s wort, vitamin B6, magnesium and others.  In cases of severe PMDD, it is likely that I will need to be more assertive with natural treatments that raise serotonin such as SAMe and tryptophan, along with the other PMS herbal/nutritional supplements.
Reference: Verkaik S, Kamperman AM, van Westrhenen R, Schulte PFJ. The treatment of premenstrual syndrome with preparations of Vitex agnus-castus: a systematic review and meta-analysis. Am J Obstet Gynecol. August 2017;217(2):150-166. doi: 10.1016/j.ajog.2017.02.028.