This study was a randomized, blinded, placebo-controlled trial to demonstrate if pre-exposure prophylaxis decreases HIV-1 acquisition among HIV-1 uninfected individuals within HIV-1 discordant couples. The HIV-1 uninfected partner was randomized in a 1:1:1 ratio to one of three arms: once daily Tenofovir Disoproxil Fumarate (TDF), Emtricitabine/Tenofovir Disoproxil Fumarate (FTC/TDF) or Placebo.