Truvada, Descovy, and Apretude are the three PrEP drugs currently available in the United States.
Truvada is a pill that contains two drugs, emtricitabine and tenofovir disoproxil fumarate (tenofovir DF). Descovy is a pill that contains two drugs, emtricitabine and tenofovir alafenamide (tenofovir AF). Apreta is a PrEP drug that contains only one drug, tenofovir alafenamide.
The difference between the two PrEP drugs is that Truvada contains the older drug, tenofovir DF, while Descovy and Apreta contain the newer drug, tenofovir AF. Tenofovir DF is slightly less effective than tenofovir AF in preventing HIV infection. However, both PrEP drugs are highly effective at preventing HIV infection.