Chaste tree fruit or Vitex agnus-castus (latin name) is one of the most popular and effective herbal medicines for the treatment of PMS and menstrual cycle irregularities. It has a long history of use for hormone balancing, dating back to 2000 years ago in ancient Greece. Today extracts of this herb are commonly prescribed to help relieve symptoms associated with hormonal imbalances such as the depression, cramps, mood swings, water retention and weight gain associated with the menstrual cycle.
There are a number of scientific studies which support its use for treating PMS including a randomized placebo controlled trial reported in the British Medical Journal which concluded that Chaste tree is “an effective and well-tolerated treatment for the relief of symptoms of PMS”. In addition, another notable clinical trial demonstrated that chaste tree is as effective as fluoxetine (Prozac) for PMDD (premenstrual dysphoric disorder) where depression is a significant during the premenstrual period.
Beyond PMS, how is Chaste tree used? As a unique hormone balancer, this botanical medicine it is often used to help the body regain a normal balance after the use of the birth control pill. Chaste tree is also effectively used in the treatment for infertility, particularly when this has to do with low progesterone. It is also a key herbal medicine in the treatment of many gynecological symptoms or conditions, such as uterine fibroids, ovarian cysts and PCOs (polycystic ovarian syndrome). Finally, towards the later years of a woman’s reproductive life, chaste tree is used in herbal formulas designed to alleviate the symptoms of the menopause transition.
How is this herb able to work in so many situations? There are a number of mechanisms for Chaste tree works as a hormone balance “tonic”. It has been shown that Vitex works on the HPO (Hypothalamic Pituitary Ovarian) axis—the interplay of hormones between our brain and our ovaries that works with a feedback loop. Ultimately what this leads to an increase in progesterone, and a normalizing of the luteal phase or second half of the menstrual cycle. In clinical practice we often find through lab testing that a number of the symptoms a woman may experience as “PMS” is actually the result of having low amounts of progesterone relative to estrogen (a common term for this is estrogen dominance which has been written about in previous newsletters). In addition, some women have a “luteal phase defect” where they experience short menstrual cycles (i.e. more frequent menstrual periods) caused by insufficient progesterone secretion. Chaste tree has been shown to beneficially affect these conditions.
A precaution: Chaste tree should not be taken with the birth control pill as it may decrease its effectiveness. Herbs are powerful medicines and can work on the same systems as many of our pharmaceutical medications, so it is always a good idea to consult with a naturopathic doctor to rule out any drug-herb interactions.
Atmaca M et al: Fluoxetine versus Vitex agnus castus extract in the treatment of premenstrual dysphoric disorder, Hum Psychopharmacol 18(3):191-195, 2003.
Milewicz A, Gejdel E, Sworen H, et al. Vitex agnus castus extract in the treatment of luteal phase defects due to latent hyperprolactinemia. Results of a randomized placebo-controlled double-blind study [in German]. Arzneimittelforschung. 1993;43(7):752-756.
Schellenberg R: Treatment for the premenstrual syndrome with agnus castus fruit extract: prospective, randomised, placebo-controlled study, BMJ 20;322(7279):134-137, 2001.