Phytoestrogens are naturally occuring non-steroidal plant-originated substances that exhibit oestrogen-like bioactivity in human body. In recent years, phytoestrogens have created much interest among the pharmaceutical industry, in an attempt to find effective alternatives to hormon replacement therapy (HRT) as man), women are reluctant. to take estrogenic drugs because of side effects. Therefore, the sales of phytopharmaceuticals containing soy (Glycine max), red clover (Trifolium pratense) and Black cohosh (Cimicifuga racemosa) extracts has increased in many countries. Apart from their estrogenic properties, phytoestrogens particularly isoflavones have antioxidant effects due to their polyphenolic structure. Isoflavones can prevent oxidative DNA damage by their free radical scavenging activity. It is known that antioxidants are defensive against aging and degenerative diseases of aging such as cancer and cardiovascular diseases. Phytoestrogens have also been effective for preventing human skin carcinogenesis and skin ageing.