Researchers at the University of Pennsylvania harness artificial intelligence to examine over 410,000 Reddit posts, revealing possible overlooked side effects of popular diabetes and weight-loss medicines such as Ozempic and Wegovy, including menstrual and temperature-related symptoms.
Researchers at the University of Pennsylvania have used artificial intelligence to sift through more than 410,000 Reddit posts about semaglutide and tirzepatide, two widely used GLP-1 weight-loss and diabetes medicines sold under brand names including Ozempic, Wegovy, Mounjaro and Zepbound. In a paper published in Nature Health, the team said 67,008 users appeared to be taking the drugs, and 43.5% of them described at least one side effect.
The findings suggest that some complaints discussed online may be slipping past routine reporting and even current drug labelling. Alongside the familiar gastrointestinal problems seen in clinical trials, the researchers highlighted two less established clusters of symptoms: menstrual changes and temperature-related complaints such as chills, feeling cold, hot flushes and fever-like sensations. Fatigue also stood out as a common report, even though it has been less prominent in formal trials.
Among users who mentioned side effects, nausea was the most common complaint at 36.9%, followed by fatigue at 16.7%, vomiting at 16.3%, constipation at 15.3% and diarrhoea at 12.6%, according to the study. Nearly 4% of those reporting side effects described reproductive symptoms, including bleeding between periods, heavy bleeding and irregular cycles. Neil Sehgal, the study’s first author, said the menstrual findings were “a signal worth investigating”, while stressing that the analysis does not prove the drugs caused the symptoms.
The work also points to the promise and limits of using social media for drug safety surveillance. Sharath Chandra Guntuku, the senior author, said the method can move faster than clinical trials, while co-author Lyle Ungar compared online patient forums to “a neighbourhood grapevine”. But the researchers warned that Reddit users are not representative of all patients, and that self-selected posts cannot establish cause and effect. Jena Shaw Tronieri said the pattern may justify more systematic study, especially because the drugs are believed to act partly through the hypothalamus, a brain region involved in hormone and temperature regulation. For now, the practical message is narrower: patients should not stop treatment on the basis of forum posts alone, but unusual bleeding, persistent chills or severe fatigue should be raised with a clinician and, if needed, reported through the FDA’s MedWatch system.
Disclaimer: This content is for informational purposes only and is not intended to be a substitute for professional medical judgment, advice, diagnosis, or treatment.
