The efficacy of Hypericum perforatum (St John's wort) for the treatment of premenstrual syndrome: a randomized, double-blind, placebo-controlled trial
https://www.ncbi.nlm.nih.gov/pubmed/20155996
--->Hypericum perforatum was statistically superior to placebo in improving physical and behavioural symptoms of PMS (p < 0.05). There were no significant effects of Hypericum perforatum compared with placebo treatment for mood- and pain-related PMS symptoms (p > 0.05). Plasma hormone (FSH, LH, estradiol, progesterone, prolactin and testosterone) and cytokine (IL-1beta, IL-6, IL-8, IFNgamma and TNFalpha) levels, and weekly reports of anxiety, depression, aggression and impulsivity, also did not differ significantly during the Hypericum perforatum and placebo cycles (p > 0.05).
Effects of a combination of Hypericum perforatum and Vitex agnus-castus on PMS-like symptoms in late-perimenopausal women: findings from a subpopulation analysis.
https://www.ncbi.nlm.nih.gov/pubmed/19757982
-->At the end of the 16-week treatment phase, analyses of covariance showed the herbal combination to be superior to placebo for total PMS-like scores (p = 0.02), PMS-D (p = 0.006), and PMS-C clusters (p = 0.027). The active treatment group also showed significant reductions in the anxiety (p = 0.003) and hydration (p = 0.002) clusters, using paired-samples t tests. Results of trend analyses showed significant treatment group effects across the five phases for total PMS and all subscales, all in the clinically expected direction. No significant trends were evident in the placebo group
Dietary supplements and herbal remedies for premenstrual syndrome (PMS): a systematic research review of the evidence for their efficacy
https://www.ncbi.nlm.nih.gov/pubmedhealth/PMH0022866/
-->There was evidence of benefit for calcium and vitamin B6 and mixed findings for magnesium and evening primrose oil. There were insufficient data to support the use of St. John's Wort, agnus castus or ginkgo biloba. Further research is required.