How can I safely restart PrEP? If you have not had sex since stopping, then it’s okay to start PrEP as usual. If you’re a cis man, you should take a double dose 2 to 24 hours before sex if you want to have sex straight away. You can then continue with either daily dosing or event-based dosing (see above). Everyone else should take daily doses for seven days before sex. This includes for vaginal/frontal protection.