How much of a difference can one little “r” make? When it comes to PrEP vs. PEP, a lot.

Both of these types of pills help prevent an HIV-negative person from getting HIV even if they have sex without a barrier with an HIV-positive person or inject drugs with a needle an HIV-positive person used. But there are a few differences between PEP and PrEP to understand.

PrEP is pre-exposure prophylaxis, which means it needs to be taken before the potential exposure to HIV. PrEP is taken once a day, every day, on a long-term basis.

On the other hand, PEP is post-exposure prophylaxis, which means it’s taken after the potential exposure to HIV. You take it within 72 hours of the exposure and then every day for 4 weeks and then stop. They’re both effective when taken as prescribed.

So, what else do you know about these two similar but different drug types? Let’s find out.