Isoflavonoids belongs to a class of flavonoid phenolic compounds which are biologically active. Isoflavonoids are also referred as phytoestrogens as isoflavonoid compounds have biological effects by estrogen receptor. Isoflavonoids and associated compounds are used in dietary supplements but scientific and medical community is generally doubtful of their use. Currently, some natural isoflavonoids are recognized as toxins including biliatresone which might cause biliary atresia when infants are exposed to plant product. The broad isoflavonoid group includes various structurally similar groups that includes isoflavonones, isoflavones, isoflavans, rotenoids and pterocarpans. Isoflavonoids are derived from flavonoid biosynthesis pathway by naringenin or liquiritigenin.
Isoflavonoid could be obtained from dietary sources such as soy and red clover.