The most common side effects from PEP medications are nausea and generally not feeling well. Other possible side effects include headaches, fatigue, vomiting and diarrhea. For more information, see fact sheets 420 through 446 on individual antiviral medications. The benefits of PEP for non-occupational exposure have not been proven. This use of PEP is controversial because some people fear it will encourage unsafe behaviors.
PEP is a four-week program of two or three antiviral medications, several times a day.
The medications have serious side effects that can make it difficult to finish the program.