(±)-Equol is a nonsteroidal estrogen. It is an active product of the soy isoflavone daidzein, produced in the human gut through metabolism by specific gut microbiota, and is not directly present in soybeans. (±)-Equol has attracted widespread attention due to its selective binding to estrogen receptor β (ERβ). Its biological activity is considered to be stronger than that of its precursor daidzein, and it is mainly used to relieve menopausal symptoms (such as hot flashes), improve bone health, and has potential cardiovascular and cognitive benefits.