Non-prescription weight loss substances, such as supplements and herbal remedies, can be harmful. Hispanic immigrant students may be highly susceptible to these substances, especially those advertised on social media. This study was a feasibility/acceptability pilot trial of an intervention to reduce this susceptibility. Latino or Hispanic immigrant students aged 18-35 were randomized to receive either a single-session, culturally tailored online intervention (Redes Sociales Para la Salud), or a dose-matched intervention focused on general support for immigrant students (Immigrant Support). Following the intervention, participants answered quantitative and open-ended questions about intervention satisfaction, and completed measures of susceptibility to non-prescription weight loss substances. Participants additionally completed measures of social media use and social norm perceptions. Fifty-five participants enrolled in the study, and 32 had primary outcome data. Participants were majority female (62.5%) and graduate students (81.3%) with a mean BMI of 24.6 ± 3.5 kg/m. Ratings of intervention satisfaction were moderate (3.5-3.7 out of 5). In open-ended questions, participants identified areas of high satisfaction (cultural appropriateness, learning new information) and suggested improvements (increase interactivity, improve presentation appearance). Considering signal of an effect, participant ratings indicated that susceptibility to non-prescription weight loss substances was lower after Redes Sociales Para la Salud compared to the control intervention. In exploratory analyses, susceptibility to non-prescription weight loss substances was positively associated with extent of social media use (r = 0.41-0.46) and social norms about use of these substances (r = 0.38). With additional refinement, the Redes Sociales Para la Salud has promise for addressing susceptibility to non-prescription weight loss substances.