BACKGROUND: Sexual and gender expansive (SGE) individuals in Kazakhstan are disproportionately affected by HIV yet stigma and discrimination pose ethical and practical challenges for HIV prevention research involving them. Although researchers are tasked with ensuring that risks of research participation are reasonable in relation to its benefits, participant-reported risks and benefits of research participation-including negative (NSIs) and positive social impacts (PSIs) on personal relationships, social status, health, and other life domains-among SGE populations have received little attention. METHODS: We examined NSIs and PSIs of research participation among SGE individuals in a three-city HIV prevention study in Kazakhstan at the trial's follow-up visits. We analyzed responses from 579 unique participants who completed a total of 2648 follow-up visits over the 36-month study period (2019-2022). RESULTS: Overall, NSIs were rare: 9 (2%) participants reported NSIs during the study
nearly no NSIs ( =0.0037, SD=0.03) were reported at follow-up visits. These few NSIs included 'trouble with friends, family, or acquaintances' and 'other'. By contrast, PSIs were extensive: 515 (89%) participants reported PSIs during the study
an average of almost five PSIs ( =4.8, SD=3.4) were reported at follow-up visits. The most frequently reported PSIs were 'gained knowledge', 'improvement in HIV-related issues', and 'improvement in mental health'. CONCLUSIONS: Our findings demonstrate the potential for HIV prevention research to be associated with PSIs for SGE individuals experiencing stigmatization and discrimination. Future research should address NSIs, particularly confidentiality breaches and interpersonal challenges, within HIV prevention research to minimize risks and burdens of participation.