"Preexposure prophylaxis (PrEP) is a medicine taken daily that can be used to prevent getting HIV. PrEP is for people without HIV who are at very high risk for getting it from sex or injection drug use. People at high risk who should be offered PrEP include about 1 in 4 sexually active gay and bisexual men*, 1 in 5 people who inject drugs, and 1 in 200 sexually active heterosexual adults. When taken every day, PrEP is safe and highly effective in preventing HIV infection. PrEP is even more effective if it is combined with other ways to prevent new HIV infections like condom use, drug abuse treatment, and treatment for people living with HIV to reduce the chance of passing the virus to others. Many people who can benefit from PrEP aren't taking it. If more health care providers know about and prescribe PrEP, more HIV infections could be prevented..."