FMO3 is also involved in the metabolism of many xenobiotics (i.e., exogenous compounds which are not normally present in the body), such as the oxidative deamination of amphetamine.
FMO3 isto tako učestvuje u metabolizmu mnogih ksenobiotika (i.e., egzogenih jedinjenja koja nisu normalno prisutn u telu), kao što je oksidativna deaminacija amfetamina.