Prep stands for pre-exposure prophylaxis, which is a medicine taken to prevent getting HIV from sex or injection drug use. When taken as prescribed, it is highly effective for preventing HIV. PrEP reduces the risk of getting HIV from sex by about 99% when taken as prescribed, and among people who inject drugs, it reduces the risk by at least 74% when taken as prescribed. PrEP is much less effective when it isnt taken consistently. There are two oral medications approved for daily use as PrEP, which are combinations of two anti-HIV drugs in a single pill. PrEP is not the same thing as PEP (post-exposure prophylaxis), which is a short-term treatment for people who’ve already been exposed to HIV within the past 72 hours. PrEP is generally an ongoing daily pill or bi-monthly shot for people who may be exposed to HIV in the future. PrEP is approved by the FDA and has been shown to be effective.