Pre-exposure prophylaxis (PrEP) How does it work? What is PrEP?  PrEP stands for pre-exposure prophylaxis. It is a prescription medication that is taken by HIV-negative people to prevent them from becoming infected with HIV. Who is PrEP for?  PrEP is for people who do not have HIV and are at higher risk of becoming infected with HIV. For example: • If you are a cis man, a trans man, or transgender woman who has anal sex with men • If your sexual partners have anal sex with men • If you wish to become pregnant through sexual activity with someone who has HIV • If you have a sexual...