Agnus castus berries are usually dried out, then made into either a powder (taken as capsules) or a tincture. It can also be used as an essential oil.
PMS – a 2012 Iranian study found that agnus castus could offer relief from mild to moderate PMS symptoms, including headaches, depression and bloating,5 while German researchers reported in 2000 that the herb could reduce – and in some cases, entirely stop – PMS symptoms.6
Menopausal symptoms – according to a study published in the Journal of Alternative and Complementary Medicine in 2009, there is enough ‘emerging pharmacological evidence’ to recommend agnus castus as a way to manage menopause symptoms, particularly the PMS-like symptoms that occur during the perimenopause.7
An earlier 2003 study concluded that applying agnus castus essential oil to the skin could ease symptoms such as hot flushes, night sweats, sleep patterns and irregular periods.8Fertility problems – thanks to its effect on prolactin, agnus castus could improve female fertility, particularly in women who have a shortened second-half of their menstrual cycle.9 Several studies have found that agnus castus can rebalance hormones and lengthen menstrual cycles, regulate periods and even lead to successful pregnancies.10
However, most of the research involved supplements that combined agnus castus with other vitamins or herbs, so further studies are needed to isolate its effects.
Sources
1. European Medicines Agency. Assessment report on Vitex agnus-castus L., fructus. Available from: https://www.ema.europa.eu/documents/herbal-report/final-assessment-report-vitex-agnus-castus-l-fructus-revision-1_en.pdf
2. European Medicines Agency. Agni casti fructus. Available from: https://www.ema.europa.eu/en/medicines/herbal/agni-casti-fructus
3. As above
4. Daniele C, et al. Vitex agnus castus: a systematic review of adverse events. Available from: https://www.ncbi.nlm.nih.gov/pubmed/15783241
5. Zamani M, Neghab N, Torabian S. Therapeutic effect of Vitex agnus castus in patients with premenstrual syndrome. Available from: https://www.ncbi.nlm.nih.gov/pubmed/22359078
6. Loch EG, Selle H, Boblitz N. Treatment of premenstrual syndrome with a phytopharmaceutical formulation containing Vitex agnus castus. Available from: https://www.ncbi.nlm.nih.gov/pubmed/10787228
7. van Die MD, et al. Vitex agnus-castus (Chaste-Tree/Berry) in the treatment of menopause-related complaints. Available from: http://anyflip.com/kfvb/wlzq/basic
8. Lucks BC. Vitex agnus castus essential oil and menopausal balance: a research update. Available from: https://eurekamag.com/pdf/004/004384381.pdf
9. Alina Petre. Healthline. Vitex Agnus-Castus: Which Benefits of Chasteberry Are Backed by Science? Available from: https://www.healthline.com/nutrition/vitex#womens-reproduction
10. As above
11. As Source 1
12. As Source 2