In Germany, PrEP medication is only approved for daily use. Taking one pill a day is also the safest way to protect yourself from an HIV infection with PrEP. Since in this case protection is available in your body “around the clock”, you can have sex spontaneously without having to plan it beforehand.
When you start taking the tablets, the level of active components builds up in the body so that you are protected after two days or more specifically after taking one pill a day on two consecutive days.
If you find that PrEP is not your prevention method after all and you want to stop taking the medication, it is a good idea to take the pills for an extra two days after the last time you had sex to prolong the protective effect in the body. If you stop taking the tablets, you are no longer protected against an HIV infection. If you want to restart taking PrEP at some point (and you still have some pills at home), it is important to have an HIV test done beforehand again to make sure that you have not been infected with HIV in the meantime.
In case you have further specific questions you can of course always contact Hein & Fiete or your doctor.