What people are actually saying

The most common category of side effects? No surprise there, it was gastrointestinal symptoms. Posts mentioning Mounjaro and general GLP-1 use were most likely to reference nausea, vomiting, constipation, or diarrhoea.

But the study didn’t stop at stomach issues. Several other patterns stood out:

• Headache and joint pain came up more often in tirzepatide-related posts (like Mounjaro and Zepbound) than with semaglutide-based meds.

• Hair loss was mentioned in around 2% of Mounjaro posts, a small but consistent signal.

• Depression and anxiety were most often linked to semaglutide-based drugs like Ozempic and Wegovy. The study doesn’t claim these meds cause mood symptoms, but the trend was strong enough to raise a flag for further research.

Interestingly, the researchers also spotted clusters of side effects that frequently appeared together, such as fatigue and nausea, or anxiety and indigestion, hinting at deeper patterns that may warrant more attention in future studies.

Real-world events = real spikes in chatter

Side effect mentions on Facebook weren’t random. They spiked around major events, like Oprah Winfrey’s public endorsement of weight loss jabs in December 2023, the FDA’s approval of Wegovy for teens, and the expansion of Medicare coverage for GLP-1s in early 2024.

This supports what many already suspect: that media coverage and celebrity influence don’t just drive prescriptions, they also shape public awareness of side effects.

A major new study turns social media noise into medical insight, and highlights what people are actually experiencing on GLP-1 meds like Ozempic, Wegovy, Mounjaro, and Zepbound.

The rise of weight loss jabs like Ozempic and Mounjaro has come with something medicine hasn’t seen before: millions of people sharing their day-to-day experiences publicly, in real time.

Now, researchers have turned that online chatter into serious science, analysing over 59,000 Facebook posts to track how real users describe side effects from GLP-1 medications. The result? A clearer picture of what’s common, what’s emerging, and what might be slipping through the cracks of clinical trials.

A different kind of data

The study, published in JMIR Infodemiology, was led by a team of doctors and public health experts from the University of Maryland and NIH. It focused on US-based Facebook posts from 2022 to 2024, specifically mentioning GLP-1 medications used for weight loss, including Ozempic, Wegovy, Mounjaro, and Zepbound.

Unlike clinical trials, which tend to be small, selective, and time-limited, this approach captured a wide range of real-world voices, including people who might otherwise be underrepresented in research. The volume of data gave researchers a rare look at how side effects show up, overlap, and evolve over time.

And it wasn’t just vague complaints. Using network analysis, the study found specific patterns of symptoms that tend to show up together, offering clues about how different systems in the body may be affected.