Effectiveness of natural S-equol supplement for premenstrual symptoms: protocol of a randomised double-blind placebo-controlled trial

摘要

IntroductionPremenstrual syndrome (PMS) comprises a range of mood, behavioural and physical symptoms, and impairs many women’s quality of life. Isoflavones are expected to stabilise the natural fluctuation of the oestrogen cycle through their selective oestrogen receptor modulator-like activities that alleviate PMS symptoms. Equol, a metabolite of a soy isoflavone converted from daidzein by specific gut bacteria, has a greater bioavailability compared with other soy isoflavones. We aim to examine the effect of natural S-equol supplements on premenstrual symptoms.