Herb of the Month – Vitex Agnus-Castus

🌿 This month’s herb of the month is chaste tree, a favourite remedy among Western herbalists and naturopaths for a broad range of women’s premenstrual, menstrual and perimenopausal symptoms and conditions 🌿

🌿 Botanical name and description:

Chaste tree, or Vitex agnus-castus, is a deciduous perennial shrub growing up to 5 metres in height. Native to the Mediterranean and central Asia, it features green leaves and violet flowers emerging from long stalks, and highly aromatic purple to black coloured berries, which are the part of the plant that’s used medicinally. Chaste tree grows in a broad range of climates and conditions, but prefers full sun and well-drained soils.

🌿 History and traditional uses:

Vitex agnus-castus has a very long history of medicinal use, which dates back to at least ancient Egyptian, Greek and Roman times. Writing in the first century AD, Pliny makes reference to the use of the herb for the maintenance of chastity, which explains its common name, chaste tree. Both Hippocrates and Discorides noted the effects of the herb on the female reproductive system, and much later, in the 19th century, the North American Eclectics made use of the herb for a broad range of hormonally mediated conditions. In more modern times, the herb is particularly well known and popularly used in Germany, where it has been the subject of scientific investigations since the 1930s.

🌿 Actions and usage today:

Among its various actions and indications, chaste tree is particularly valued by practitioners for its effectiveness in the treatment of premenstrual, menstrual and peri-menopausal symptoms and conditions. Some specific indications include premenstrual syndrome and associated mastalgia, abnormal uterine bleeding, cysts, fibroids and endometriosis, erratic ovulation and PCOS, other conditions characterised by excess oestrogen, and for enhancing fertility. In addition to these uses, the herb is prescribed in all genders for the treatment of acne, and may also be beneficial for the treatment of stress, anxiety and sleep maintenance insomnia. Its primary mechanisms of action appear to be its prolactin inhibiting and progesterogenic effects.

🌿 Science and clinical trials:

Modern day clinical trials are increasingly reinforcing some of the above traditional uses of Vitex agnus-castus, in particular, for the relief of premenstrual syndrome and mastalgia.

In a 2013 systematic review of randomised controlled trials, seven of eight trials evaluating the efficacy and safety of chaste tree for the treatment of premenstrual syndrome demonstrated the herb to be superior to placebo (5 out of 6 studies), pyridoxine (1 study) and magnesium oxide (1 study). The authors noted that the overall methodological quality of the trials was moderate to high, however, limitations of their review included some studies having small sample sizes, the range of the reference treatments, and the diversity of the symptoms being treated. They recommended further research and greater reporting transparency in future trials (1).

More recently, a 2020 systematic review and meta-analysis of the efficacy of chaste tree for the treatment of cyclic mastalgia examined 25 studies (17 randomised controlled trials and 8 non randomised trials). The typical dose of the herb administered was 20-40 mg per day for a duration of 3 months. The authors concluded that the herb was safe (with only mild and reversible adverse events reported) and effective in reducing serum prolactin levels and the intensity of breast pain in reproductive age patients with cyclic mastalgia. They noted, however, that there was insufficient information to assess risk of bias and recommended further high-quality clinical trials to enhance the herb’s evidence base (2).

(1) Van Die MD, Burger HG, Teede HJ, Bone KM. (2013) Vitex agnus-castus extracts for female reproductive disorders: A systematic review of clinical trials. Planta Med. 79(7):562-75. doi: 10.1055/s-0032-1327831

(2) Ooi SL, Watts S, McClean R, Pak SC. (2020) Vitex Agnus-Castus for the Treatment of Cyclic Mastalgia: A Systematic Review and Meta-Analysis. J Womens Health (Larchmt). 29(2): 262-278. doi: 10.1089/jwh.2019.7770.