Phase 1: Consists of a 28-day study period, with a single dose of study product on Day 0 (Maraviroc, Dolutegravir, or tenofovir/emtricitabine). Day 0 can be scheduled on either Mondays or Tuesdays, and once eligibility is confirmed on the day of enrollment, a witnessed dose of study product will be administered. Participants will return to the clinic for hair and blood sampling on Days 3/7/14/21/28 days post-dose. Adverse events will be assessed at every visit. Safety labs will be drawn at the midpoint and at the end of the study phase, and at any time indicated due to suspected adverse events. These visits should last less than 30 minutes.