HIV and AIDS
Pre-exposure prophylaxis (PrEP) involves having anti-HIV drugs in your body before you are exposed, to prevent infection.
This is usually with a combination pill containing tenofovir disoproxil and emtricitabine. There is another effective type of PrEP containing a different type of tenofovir (tenofovir alfenamide) but this is not available on the NHS. Other drugs are only available in research studies.