Many clinical studies have been carried out to determine the health benefits of soy protein and the isoflavones contained in soy. S‐equol is not present in soybeans but is produced naturally in the gut of certain individuals, particularly Asians, by the bacterial biotransformation of daidzein, a soy isoflavone. In those intervention studies in which plasma S‐equol levels were determined, a concentration of >5–10 ng/mL has been associated with a positive outcome for vasomotor symptoms, osteoporosis (as measured by an increase in bone mineral density), prostate cancer, and the cardiovascular risk biomarkers low‐density lipoprotein cholesterol and C‐reactive protein. These studies suggest that S‐equol may provide therapeutic benefits for a number of medical needs.