BACKGROUND: Low adherence has contributed to disappointing results for trials testing vaginal microbicides for HIV prevention. This study engaged former gel trial participants to understand the reasons behind low adherence and seek suggestions on how to improve products and adherence to microbicides. This analysis examines the impact of participant perceptions of male partners on participant adherence and suggestions on how to address those issues. METHODS: Eight focus group discussion workshops were conducted with 46 former microbicide trial participants in South Africa and Tanzania. Participants provided feedback on why women join trials, barriers to using gels and reporting adherence accurately, and how adherence and adherence reporting can be improved. RESULTS: Participants reported that male partners can affect women's ability to use gels. For some, the lubricating effects caused relationship conflicts due to suspicion of male partners about infidelity. Needing to provide sex to partners on demand was a barrier to gel use. Participants suggested a gel formulation which was thicker and less noticeable, and explicit male partner engagement to enhance understanding of the purpose of the gels. CONCLUSIONS: The imbalance of power in intimate relationships affects the ability of women to use microbicides as directed. To improve adherence to HIV prevention methods within trials and for successful rollout of proven HIV prevention methods in populations, it is important that the complicated dynamics of sex and relationships be taken into greater consideration and that women receive targeted support to navigate product use and communication within the context of these gender dynamics.