Feasibility and Acceptability of Digital Pills to Monitor PrEP Adherence in MSM With Substance Use

This study deploys a novel digital pill with Emtricitabine/Tenofovir (TDF/FTC) among MSM with substance use to monitor PrEP adherence. The investigators will enroll N=15 HIV uninfected MSM with self reported substance use who are on PrEP or initiating PrEP to use digital pills over encapsulating TDF/FTC for 3 months. The investigators will assess the feasibility of using digital pills in this study population as well as understand the acceptability of digital pills for adherence measurement using semi-structured individual interviews. Additionally, the investigators will measure adherence over time, as well as episodes of suboptimal PrEP adherence.