PrEP (pre-exposure prophylaxis): Involves taking an FDA-approved medication every day and getting regular medical care, including health checks and lab tests. If taken daily, PrEP can reduce the risk of HIV infection by more than 90 percent. PrEP can be used by people who do not have HIV yet are at risk for acquiring it.

PEP (post-exposure prophylaxis): A short-term medication treatment that reduces the likelihood of HIV infection after potential exposure to HIV. PEP (post-exposure prophylaxis) consists of an FDA-approved combination of anti-HIV medications that are taken for 28 days to reduce the risk of HIV infection after contact with someone who is or may potentially be HIV-positive. In order to work, PEP must be started as soon as possible (and no later than 72 hours) after exposure.