Equol (R, S)

(±) -Equol is a non-steroidal estrogen metabolite of daidzein with selective affinity for ERβ over ERα. Its (S) -enantiomer acts as a potent ER agonist, while the racemate also functions as a dihydrotestosterone antagonist. This dual activity makes it a valuable research tool for studying hormone-dependent cancers and endocrine pathways in vitro and in vivo.