PEP(post exposure prophylaxis) is a treatment to prevent a person from becoming HIV positive due to possible exposure to HIV. PEP treatment is the only treatment to get prevention from HIV infection due to possible exposure to HIV. It should be started within the 72 hours of possible exposure to HIV. The golden period to prevent yourself from becoming HIV positive. PEP (post exposure prophylaxis) is the systemic treatment therapy for patients exposed to HIV within 72 hours of possible exposure. The word prophylaxis means to prevent or protect. Watch Full Video for more information.