PEP refers to “post-exposure prophylaxis” vs. PrEP which refers to “pre-exposure prophylaxis.” PEP is a treatment plan for after a person has been exposed to HIV. It includes taking antiretroviarl medication as soon as possible after exposure to HIV. PrEP is a medication that is taken prior to exposure to HIV as a way to prevent getting HIV. It can be taken daily in pill form, or by injection every other month. (New deliivery systems are in the works.) Hopefully any sexually active gay or bisexual man who is on the prowl will take PrEP so he never has to go through the nightmare of getting HIV, which is completley unnecessary now that we have an effective way to prevent it. Also, up to 25% of new HIV cases are in people who are straight. So if you are straight and might be at risk for getting HIV, you should definitely start using PrEP. See PrEP