Pre-exposure prophylaxis is a method to prevent HIV contraction in individuals who are at a high risk of acquiring it. Some of the medicines that are used to treat HIV can also be used to prevent it. In PrEP treatment, the HIV-negative individual takes HIV medicines daily.
PrEP when done right, can reduce the risk of catching HIV by 90%. When combined with other methods of protection like condoms, for example, the risk is reduced further.