Methiocarb and carbaryl were hydrolyzed by rat plasma and albumin.
The hydrolyzed products showed strong estrogenic and antiandrogenic activities.
Methiocarb and the hydrolyzed product were oxidized to their sulfoxides.
These conversions were mediated by P450 and flavin-containing monooxygenase.
Their sulfoxide products lacked estrogenic and antiandrogenic activities.