Phytoestrogens (PE) are widely used as a dietary supplement. PE affect oestrogen receptors. PE have been investigated regarding menopausal hot flushes, bone mineral density and prostate hyperplasia/cancer. It seems consistent, that PE increase bone mineral density, whereas the effect on hot flushes is controversial. Due to the effect on oestrogen receptors, concerns exist on the risk of cancer and venous thromboembolism related to the intake of PE. To date, no studies with PE have been large enough to clarify their safety. Widespread use of PE should therefore be discouraged.