Further Readings

Check these out for more in-depth information about vitex:

(2009). Vitex agnus-castus. Alternative Medicine Review 14: 67-70.

Blumenthal, M. (2003). The ABC Clinical Guide to Herbs. New York, NY: American Botanical Council.

Daniele, C., Coon, J.T., Pittler, M.H. & Ernst, E. (2005). Vitex agnus castus – A systematic Review of Adverse Events. Drug Safety 28: 319-332.

Dugoua, J.J., Seely, D., Perri, D., Koren, G. & Mills, E. (2008). Safety and Efficacy of Chastetree (Vitex Agnus-Castus) During Pregnancy and Lactation. Can J Clin Pharmacol 15: e74-e79.

Ernst, E. (2000). Herbal Medicine. Oxford, Boston: Butterworth- Heinemann.

He, Z., Chen, R., Zhou, Y., Zheyu, Z., Chen, S., Yao, Y., Lu, J., & Lin., S. (2009). Treatment for premenstrual syndrome with Vitex agnus castus: A prospective, randomized, multi-center placebo controlled study in China. Maturitas 63: 99-103.

Kilicdag, E.B., Tarim, E,. Bagis, T., Erkanli, S., Aslan, E., Ozsahi, K & Kuscu, E. (2004). Fructus agni casti and bromocriptine for treatment of hyperprolactinemia and mastalgia. International Journal of Gynecology and Obstretics 85: 292-293.

Roemheld-Hamm, BR. (2005). Chasteberry. American Family Physician 72: 821-824.

Rotblatt, M. & Zimment, I. (2002). Evidence-Based Herbal Medicine. Philadelphia, PA: Hanley & Belfus, Inc.  

The Science - Vitex Relationship

For the last 50 years, vitex has been used to treat problems of the female reproductive system including premenstrual syndrome (PMS), menstrual cycle irregularities, dysfunctional uterine bleeding, infertility, mastalgia, decreased lactation and acne (Rotblatt & Ziment, 2002). Although around 30 clinical trials in Europe have been conducted to study its effects, most of these studies were involved in post-market surveillance and were poorly designed (Rotblatt & Ziment, 2002). In addition, there are very few recent clinical trials done to further investigate its uses and efficacy.

The study by He et al. is one of the most current studies that examined the efficacy of vitex in relieving mild to severe symptoms of PMS (He et al., 2009). With 202 Chinese women, they were able to show that compared to placebo, vitex caused a significant improvement in the symptoms of PMS from baseline to the last month of treatment (termination). These scores were recorded using the self-assessment tools PMS diary (PMSD) and Premenstrual tension syndrome self-rating scale (PTSD). 

Although termination PMSD scores from both the placebo and the treatment groups significantly decreased from baseline (both p<0.0001), the reduction in the treatment group (22.71 ± 10.33) was significantly greater than the reduction in the placebo (15.50 ± 10.94) (p<0.0001). Termination PTSD scores were also significantly lower from baseline between and within groups (both p<0.01). Scores of the placebo group decreased by 12.44 ± 10.43 while those in the treatment group decreased by 16.63 ± 10.07. This study presented a 60% improvement in symptom scores and was considered clinically significant.

The study was described as prospective, randomized, controlled and double-blind, a type of study that provides the highest quality of evidence. Although it did not elaborate on the randomization and blinding method, this study is still commendable for including power calculations, for considering confounding factors, for using two assessment tools to measure the outcome and for reporting attrition and adverse events. The protocol was sound, detailed and properly executed, rendering the results of this study valid.  

The study by Kilicdag et al. on the other hand, is not as well designed. They studied the efficacy of vitex as a treatment for mild hyperprolactinemia and mastalgia compared to the drug bromocriptine (Kilicdag et al., 2004). The results show that there was a significant decrease in prolactin levels in both the vitex group (416.47 ± 248.93 mIU/l) and the drug group (412.36 ± 322.78 mIU/l ) (both p<0.0001) and a significant reduction in pain scores associated with mastalgia in both the vitex group (4.90 ± 2.10) and the drug group (5.32 ± 2.24) (both p<0.0001), both from baseline. There were no differences in efficacy between vitex and bromocriptine in treating hyperprolactinemia (p = 0.96) nor mastalgia (p = 0.55). 

This study was full of design flaws. The sample size was extremely small (n=20 per group per disorder), they were not randomized nor blinded, the methods used to report the outcomes, attrition rates and baseline characteristics were not reported and most importantly, there were no controls used. These serious flaws question the validity of the results, thus this study does not provide evidence of the therapeutic effects of vitex on hyperprolactinemia nor mastalgia. 

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). 

The Secret Ingredients

The purported healing properties of the ripe and dried fruit vitex are derived from its whole plant extract, which contains several active constituents. This includes flavonoids (i.e. casticin, kaemperol, quercetagetin, orientin and isovitexin), iridoid glycosides (i.e. aucubin and agnoside), essential oils (i.e. limonene, cineol, pinen and sabinene), diterpenes (i.e. vitexilactone, rotundifuran and  6-β-diacetoxy-13-hydroxy-λ-8,14-dien) and essential fatty acids (oleic acid, linoleic acid, palmitic acid and stearic acid) (Dugoua, Seely, Perri, Koren & Mills, 2008).

Most European vitex preparations appear in the form of native dry extracts such as capsules, fluid extracts as well as tinctures (Blumenthal, 2003).  In Europe, there are no official guidelines regarding the standardization of these preparations. For authentication purposes however, the iridoid glycoside agnoside and the flavonoid casticin are used as marker compounds (Blumenthal, 2003). 

Vitex In the Olden Days

Vitex , or chasteberry, is the fruit of the deciduous shrub Vitex agnus-castus. It is native to Mediterranean Europe and Central Asia (Daniele, Thompson, PIttler & Ernst, 2005) and naturalized to the warm climate of southeastern United States (Ernst, 2000).

The use of vitex dates back to ancient Greece and Rome (Blumenthal, 2003). Historically, it was believed that a beverage made with vitex promoted chastity by lowering libido (Ernst, 2000). The name agnus castus was derived from the Latin words ‘castitas’ and ‘agnus’, which mean “chastity lamb” (Daniele et al., 2005). Its other common name, monk’s pepper, refers to its use as a cooking spice by monks of the Middle Ages to suppress sexual desires (Daniele et al., 2005). The Greek historian Pliny notes that the scattering of this fruit on the bed of soldier’s wives was a sign of their faithfulness to their husbands at battle (Ernst, 2000).

 

Traditionally, phytotherapy practitioners use vitex as a treatment for gynecological problems including menstrual cycle irregularities, premenstrual syndrome, corpus luteum insufficiency, hyperprolactinemia, menopause, infertility and hormonally induced acne (Dugoua, Seely, Perri, Koren & Mills, 2008). It has also been used to treat hangovers, fevers, flatulence and constipation (Ernst, 2000). Nowadays, vitex is still widely used in Germany to treat problems of the female reproductive system (Ernst, 2000).