LLM analyzed 150k Reddit posts to identify side effects of unapproved new GLP-1

Researchers used large language models to analyze nearly 150,000 Reddit posts and comments from about 40,000 users to characterize self-reported side effects of gray-market retatrutide, a next-generation GLP-1 weight-loss peptide not yet approved for humans. The AI pipeline identified roughly 14,000 users who said they took unapproved retatrutide, extracted symptom descriptions, mapped them to standardized medical terms, and produced a working dataset of 7,823 users reporting at least one classifiable symptom. The work builds on prior LLM analyses of GLP-1 discussions and leverages automated scale to detect recurring, user-reported experiences that would be impractical to find by manual review.

The analysis found that increased appetite was the most frequently reported symptom among classifiable reports, differing from Phase 2 trial data that listed gastrointestinal issues like nausea as most common. Compared with prior Reddit analyses of semaglutide and tirzepatide, retatrutide reports contained proportionally more appetite-related complaints, sleep disturbances, higher heart rate and muscle-related changes, and fewer GI complaints. Researchers emphasize these findings are hypothesis-generating: the authenticity of gray-market products, concurrent use of other peptides, self-selection of users, and lack of causal proof limit conclusions. The dataset is presented as an early warning tool to guide targeted follow-up in clinical or regulatory datasets.