Understanding community questions about HIV pre-exposure prophylaxis (PrEP): A thematic analysis of reddit threads to inform development of an AI chatbot for PrEP education.

Abstract

Background: Despite growing availability of HIV pre-exposure prophylaxis (PrEP), many potential users turn to online forums for advice and information collection. These forums provide a window into real-world questions, concerns and misinformation. They serve as a tool for users to query for sensitive information without revealing their identities. These platforms could therefore be a potential source of understanding of the unmet needs of users. This study systematically analyses the social media posts referring to the four drugs mentioned in the study to identify common questions and thematic concerns among the community and uses this insight to inform the design of an AI-driven, privacy-preserving chatbot for PrEP education based on evidence.

Methods: Between May 2011 to October 2025, we found 1168 relevant Reddit posts mentioning one of the four names for PrEP therapies, by either brand or generic name: Truvada (Tenofovir disoproxil fumarate + emtricitabine (TDF/FTC)), Descovy (Tenofovir alafenamide + emtricitabine (TAF/FTC)), Apretude (long-acting cabotegravir), Yeztugo (lenacapavir) using a systematic search. We used Natural Language processing (NLP) techniques to understand user needs.

Results: Seven distinct discussion themes were identified within PrEP social media discourse, with side effects emerging as the most frequently discussed primary topic among 1076 posts. Across all medications, weight changes were the most frequently mentioned side effect. Truvada was the most frequently discussed PrEP medication. 96.7% of the dataset comprised questions, showing that Reddit serves as a primary information-seeking platform. Early period discussions were emphasized basic access and effectiveness questions, with more recent discussions (2022-2025) displaying increased attention to injectable and long-term safety considerations.

Conclusions: Reddit users demonstrate persistent uncertainty about PrEP side effects, drug interactions and medication switching. Drug interactions represented the most frequently identified information gap (26.5% of posts). These empirically derived information needs will inform the design of a privacy-preserving PrEP chatbot trained on authoritative UK sources (hiv-druginteractions.org, BHIVA guidelines, NHS resources).