HIV prevention is a public health priority. Despite progress in recent years, pre-exposure prophylaxis (PrEP) use remains suboptimal especially among groups disproportionately impacted by new HIV diagnoses such as gender and sexual minorities of color. Multiple barriers including a lack of PrEP providers and challenges with attending quarterly monitoring visits contribute to low PrEP uptake and retention. Home-based PrEP (HB-PrEP) services could reduce stigma, increase convenience, expand health system capacity for PrEP care, and improve PrEP retention. Home Option Testing for PrEP (HOT4PrEP) is a hybrid randomized controlled trial (RCT) that aims to examine whether HB-PrEP care is acceptable to PrEP users, feasible to implement in a sexual health clinic setting, and impacts PrEP retention. The RCT will recruit 458 persons currently taking or soon to initiate PrEP at a sexual health clinic in Seattle, Washington, and randomize them to continue the standard of care or have the option to use HB-PrEP for 2 of 3 triannual PrEP follow-up visits. Participants in the intervention arm will be sent home kits containing gonorrhea and chlamydia swabs and Tasso devices for blood self-collection. The primary outcome is PrEP retention between groups at 20 months; secondary outcomes include user satisfaction and acceptability, feasibility, self-reported PrEP adherence, and sexually transmitted infection (STI) incidence. Interviews with PrEP users and clinic staff will elucidate barriers and facilitators of implementation. The HOT4PrEP RCT began enrolling in March 2022, was on hold during the height of the US mpox epidemic, then resumed enrollment in December 2022. Of the first 100 enrollees, the median age is 34 years, and most are cisgender gay men (89/100, 89%) with at least some college education (91/100, 91%). Among the 49 participants randomized to the HB-PrEP option, 33 (67%) chose to self-collect samples at home at least once, of whom 27 (82%) successfully returned test kits for HIV and STI testing. Primary PrEP retention and qualitative analyses are ongoing. Implementation of HB-PrEP into a high-volume sexual health clinic seems to be feasible and acceptable to early RCT enrollees. This strategy has the potential to address individual and systemic barriers associated with initiating and persisting on PrEP, such as increasing sexual health agency and expanding clinical capacity to serve greater numbers of PrEP users. ClinicalTrials.gov NCT05856942; https://clinicaltrials.gov/study/NCT05856942. DERR1-10.2196/56587.