“PrEP” stands for Pre-Exposure Prophylaxis. The word “prophylaxis” means “to prevent or control the spread of an infection or disease.” PrEP is a way for people who don’t have HIV to prevent HIV infection by taking a pill every day. The pill contains two medicines that are also used to treat HIV. If you take PrEP and are exposed to HIV through sex or injection drug use, these medicines can work to keep the virus from taking hold in your body.