Lack of sufficient information on the specificity and selectivity of commercial phytoestrogens preparations for therapeutic purposes

Phytoestrogens (PEs) are polyphenols of plant origin among which flavones, flavanones, isoflavones, coumarins, chalcones, lignans and stilbenes are the best representatives. By interacting with specific residues of the estradiol-binding pocket of estrogen receptors (ERs), they induce estrogenic responses, supporting the concept that they could be of benefits against the menopausal disorders due to endogenous estradiol depletion. According to literature data, PEs target a panel of proteins, suggesting that their effects are not limited to ER-dependent transcription pathways. In this regard, commercial preparations usually contain a mixture of compounds of which nature and concentration are not specified. Such mixtures being freely accessible and escaping thereby medical survey, they could exert unwanted effects, depending on their qualitative and quantitative composition as well as the physiopathological status of the women. This work outlines the necessity to inform consumers of the exact nature of these PEs preparations. Moreover, women who want to take PEs should inform their practitioner to be under strict medical survey. In the case of hormone-dependent cancer antecedents or predispositions, use of PEs is extremely inadvisable.