The inconclusive results of past trials and recent findings of partial protection of Tenofovir 1% gel underscore the need to better understand product adherence in microbicide trials. This study aimed to identify factors predicting couples' ability to sustain topical gel and condom use during clinical trial participation. We enrolled 100 Indian participants of a randomized, controlled safety trial of Tenofovir 1% gel (CT cohort) and 100 similar women who were ineligible or declined trial participation (NCT cohort). Compared to the NCT cohort, CT women reported higher baseline condom use, more positive attitudes towards condoms and higher levels of protection efficacy. While NCT condom use remained low, CT condom use increased dramatically during the study. Reported gel consistency was higher than condom consistency. Individual and couple-related factors predicted condom consistency and interest in future gel use, but not gel consistency. Findings could inform trial recruitment strategies and product introduction.