The CDC now recommends daily treatment with Truvada (300 mg tenofovir
disoproxil fumarate and 200 mg emtricitabine) to lower the risk for
HIV acquisition among high-risk adults.

Pre-exposure prophylaxis with Truvada is recommended in the following
groups-

Men who have Sex with Men-
not in a monogamous relationship who engage in unprotected anal
intercourse

Heterosexually active adults who rarely use condoms during sex with
high-risk partners of unknown HIV status

All adults in an ongoing relationship with an HIV-infected partner

Injection drug users who share needles

Individuals must test negative for HIV before beginning Truvada, and
they should be assessed every 3 months thereafter. Those who acquire
HIV should discontinue the drug.

CDC pre-exposure prophylaxis guidelines