By using AI to analyze more than 400,000 Reddit posts, researchers in Pennsylvania identified patient-reported symptoms associated with GLP-1, the popular weight loss and diabetes drugs semaglutide and tirzepatide, that may not be fully captured in clinical trials or regulatory documents.
New research published in natural healthcovers more than five years of posts from nearly 70,000 Reddit users and focuses on two main conditions that require further research: genital symptoms, including irregular menstrual cycles, and temperature-related complaints, such as chills and hot flashes.
Some of the side effects we found, such as nausea, are well known, indicating that the method is picking up on real signals. Underreported symptoms may be derived from the patient themselves and may cause clinicians to pay attention to them. ”
Sharath Chandra Gunthuk, associate professor of computer and information science (CIS) at Pennsylvania Engineering College and senior author of the study
“Clinical trials typically identify a drug’s most dangerous side effects,” added Lyle Unger, CIS professor and co-author of the study. “But sometimes we don’t find out what symptoms patients are most concerned about. Even though social media isn’t necessarily representative, a large collection of posts can reflect additional concerns.”
The researchers cautioned that their findings are not causal. “We can’t say that GLP-1 is actually causing these symptoms,” said Neil Sehgal, lead author of the study and a CIS doctoral student advised by Gangtuk and Unger. “However, nearly 4% of Reddit users in our sample reported menstrual irregularities, and the proportion would be even higher in a female-only sample. We think this is a signal worth investigating.”
Learn social media for your health
In 2011, Ungar participated in one of the early efforts to mine user-generated content online for information about drug side effects.
“Online patient communities act like neighborhood grapevines,” Unger says. “People living with these drugs exchange notes with each other in real time and share experiences that are rarely documented in medical examinations or official reports.”
Since then, the use of social media has only increased, and data from these platforms has become increasingly promising as a source of information about drug side effects, even though the platforms themselves make the data more difficult to access. (Guntuku has also published research on strategies for adapting to changes in platform access.)
“Clinical trials are the gold standard, but by design, clinical trials are time-consuming,” says Guntuku. “This is not a replacement for clinical trials, but it can go much faster, and when drugs go from niche to mainstream almost overnight, that speed is important.”
Analyze social media with AI
The most challenging part of this process, which Guntuku calls “computational social listening,” has so far been scale.
Because users vary in how they describe their symptoms, the effort required to map individual social media posts to the Medical Dictionary for Regulatory Activities (MedDRA) language used by clinicians to describe symptoms limited the amount of data that could be processed with this approach.
Large-scale language models such as GPT and Gemini now make it possible to systematically analyze social media posts at an unprecedented scale. “Large language models allow us to perform this type of analysis much faster and at a level of standardization that was previously difficult to achieve,” Sehgal says.
Symptoms not reported
While the population the researchers studied was clearly not representative — Reddit users are younger, more likely to be male, and disproportionately based in the United States — the symptoms described in their collective reports were broadly consistent with known side effects of semaglutide and tirzepatide, with approximately 44% of users in the study reporting at least one side effect, most commonly some form of gastrointestinal distress.
What was striking was that a significant proportion of users reported symptoms that may not be fully reflected in current drug labeling or routine adverse event reporting. Approximately 4% of users who reported side effects reported genital symptoms, including menstrual changes such as intermenstrual bleeding, heavy bleeding, and irregular cycles.
Some people have reported symptoms related to body temperature, including chills, chills, hot flashes, and fever-like symptoms.
Additionally, fatigue ranks as the second most common complaint among Reddit users, despite relatively few clinical trials meeting reporting standards.
“These drugs are thought to work by acting on a part of the brain called the hypothalamus, which helps regulate various hormones,” says Jenna Shaw Toronieri, senior research scientist at the Penn State Weight and Eating Disorders Center and co-author of the study. “That doesn’t mean the drug is necessarily causing these symptoms, but it may suggest that reports of menstrual changes or body temperature fluctuations are worth studying more systematically.”
Future direction
In the short term, the researchers hope that their findings will encourage clinicians and researchers to take a closer look at the side effects that patients are discussing online. “They’re clearly in the patient’s mind, and that’s worth paying attention to,” Sehgal says.
The team also hopes to expand their work beyond Reddit and beyond the English-language community, testing whether the same patterns emerge across different platforms and populations.
“We don’t really know yet whether what we’re seeing on Reddit reflects the experiences of GLP-1 users around the world, or whether it’s unique to the type of people posting on Reddit in the United States,” Unger said.
Ultimately, researchers believe this type of AI-assisted rapid social media analysis could be a useful way to detect early warning signs about new drugs or health trends.
For substances that quickly trend online, like injectable peptides, especially those sold in less regulated or unregulated markets, patient discussion on platforms like Reddit and TikTok can provide one of the earliest clues to what users are actually experiencing.
“The key to this kind of approach is that you can move quickly, and that’s exactly when it’s most valuable,” says Guntuku.
sauce:
University of Pennsylvania School of Engineering and Applied Science
Reference magazines:
Sehgal, NKR; Others. (2026). Self-reporting of semaglutide and tirzepatide side effects in online communities. natural health. DOI: 10.1038/s44360-026-00108-y. https://www.nature.com/articles/s44360-026-00108-y
