Pre-exposure prophylaxis (PrEP) refers to preventive medication for people who are not HIV-positive but are considered to be at substantial risk of infection. According to the U.S. Centers for Disease Control, PrEP is highly effective; it reduces the risk of contracting HIV from sex by 99%.
PrEP medications fall under two brands in the U.S., Truvada and Descovy. The former is recommended for people who are at risk of HIV through sex or injection drug use. The latter is for people at risk through sex, except for people assigned female at birth who are at risk of contracting HIV through vaginal sex because its effectiveness has not been studied in this population. Both products are intended for use by people who are already HIV negative. In 2021, the FDA approved the first injectable form of PrEP called Apretude.
Both brands of PrEP contain tenofovir and emtricitabinen. Daily intake is necessary for the medication to be effective, and the research has shown that the more closely people adhere to recommended dosing, the more protection they receive. Pre-exposure prophylaxis is another layer of protection from HIV infection, on top of condoms and other preventive measures.