Modafinil slightly reduced the levels of ethinylestradiol taken as part of a combined
hormonal contraceptive. Emergency hormonal
contraceptives and progestogen-only
implants may also be less effective if taken with
modafinil.
These small changes may be sufficient to cause the failure of combined hormonal
contraceptives in rare cases. For additional advice on the use of
enzyme inducers, such as
modafinil, and
contraceptives, see
contraceptives. It is also recommended that additional or alternative methods should be continued for up to 2 cycles after stopping
modafinil.