Ojeda V, Amico KR, Hughes JP, et al. - Among daily-dosing regimen participants in HIV Prevention Trials Network (HPTN) 067, an open-label trial of oral tenofovir disoproxil fumarate 300 mg/emtricitabine 200 mg, researchers examined the relationship between 2 types of social relationships, ie, (1) external support for use of HIV pre-exposure prophylaxis (PrEP) and related study supplies and (2) participants' disclosure of PrEP use and condom use and HIV PrEP adherence. They developed scales using HPTN 067 survey data, which examined (1) Low Perceived External Support for PrEP: low perceived support by others for PrEP use or perceived negative reactions to the pill case (scoring ranges from 0 to 2) and (2) Participant–Staff Disclosure Challenges Scale, which identifies challenges to sharing nonuse of PrEP or condoms to study staff (scoring ranges from 0 to 4); these scales are the primary independent variables. This study comprised 161 participants including HIV-uninfected women in South Africa, and men who have sex with men and transgender women, in Thailand and the United States. Outcomes support that PrEP challenges are correlated with adherence, study staff–participant interactions and participants' disclosure, hence these may be worthwhile intervention targets for improving PrEP adherence in confirmatory studies.