Isoflavone
Isoflavones are a type of naturally-occurring isoflavonoids, many of which act as phytoestrogens in mammals. Isoflavones occur in many plant species, but are especially high in soybeans.
Although isoflavones and closely-related phytoestrogens are sold as dietary supplements, there is little scientific evidence for either the safety of long-term supplementation or of health benefits from these compounds. Some studies indicate that isoflavone supplementation may help lower the risk of hormone-related cancers.