Enzalutamide is converted into its major metabolites, N-desmethyl enzalutamide and carboxylic acid enzalutamide, by cytochrome P450 (CYP) 3A4/5 and CYP2C8, respectively. N-desmethyl enzalutamide has clinically relevant anti-androgen capacities similar to enzalutamide, whereas carboxylic acid enzalutamide is inactive.