Abstract

The aim of this review was to identify the effect of phytoestrogens on polycystic ovary syndrome (PCOS) (clinical evidence and laboratory findings) in women of reproductive age. Major databases were systematically searched until 1st July 2017. The Jadad scale was used for evaluating the quality of trials. Compared to placebo, there is a variable and inconclusive result regarding the effect of soy on testosterone. The luteinizing hormone (LH), the follicular stimulating hormone (FSH), and dehydroepiandrosterone sulphate (DHEAS) are not affected significantly either. No significant changes in the menstrual cycle were observed following treatment with soy. Following the administration of flaxseed, testosterone and DHEAS levels did not change significantly but 33.3 of patients had a normal menstrual cycle and 10 of patients become pregnant. Cimicifuga racemosa alone, or in combination with clomiphene, had a beneficial effect on decreasing serum LH. Ninety-five percent of patients reported irregular cycle at baseline, while 71.4 of patients receiving fenugreek seed extract (Trigonella foenum-graecum) had a normal cycle at the end of the study. There is scientific evidence that phytoestrogens, such as flaxseed and the fenugreek seed extract, may have effects on ovulation regulation. However, the currently available evidence on the effect of phytoestrogens on PCOS endocrine disorder is inconclusive.