AI scans 400,000 Reddit posts to flag overlooked GLP-1 side effectsby University of Pennsylvania edited by Sadie Harley, reviewed by Robert Egan By using AI to analyze more than 400,000 Reddit posts, Penn researchers have identified patient-reported symptoms associated with GLP-1s, the popular weight-loss and diabetes drugs semaglutide and tirzepatide, that may not be fully captured in clinical trials or regulatory documents. The new study, published in Nature Health, covers more than half a decade of posts from nearly 70,000 Reddit users and highlights two main classes of symptoms that warrant further study: reproductive symptoms, including irregular menstrual cycles, and temperature-related complaints, such as chills and hot flashes. "Some of the side effects we found, like nausea, are well known, and that shows that the method is picking up a real signal," says Sharath Chandra Guntuku, Research Associate Professor in Computer and Information Science (CIS) at Penn Engineering and the study's senior author. "The underreported symptoms are leads that came from patients themselves, unprompted, and clinicians could potentially pay attention to them." "Clinical trials generally identify the most dangerous side effects of drugs," adds Lyle Ungar, Professor in CIS and a co-author on the study. "But they can fail to find what symptoms patients are most concerned about; even though social media is not necessarily representative, a large collection of posts may reflect additional concerns." The researchers caution that their findings are not causal. "We can't say that GLP-1s are actually causing these symptoms," notes Neil Sehgal, the study's first author and a doctoral student in CIS advised by Guntuku and Ungar. "But nearly 4% of the Reddit users in our sample reported menstrual irregularities, which would be even higher in a female-only sample. We think that's a signal worth investigating." Studying social media for healthIn 2011, Ungar participated in one of the earliest efforts to mine online, user-created content for information about drugs' adverse effects. "Online patient communities work a lot like a neighborhood grapevine," says Ungar. "People who are living with these medications are swapping notes with each other in real time, sharing experiences that rarely make it into a doctor's office visit or an official report." In the years since, social media use has only grown, making data from these platforms increasingly promising as a source of information about the side effects of medications, even as the platforms themselves have made accessing the data more difficult. (Guntuku has also published research on strategies for adapting to changes in platform access.) "Clinical trials are the gold standard, but by design, they are slow," says Guntuku. "This is not a replacement for trials, but it can move much faster, and that speed matters when a drug goes from niche to mainstream almost overnight." Leveraging AI to analyze social mediaUntil now, the most challenging part of this process, which Guntuku calls "computational social listening," has been scale. Because users vary in how they describe their symptoms, the effort required to map individual social media posts to language in the Medical Dictionary for Regulatory Activities (MedDRA), which clinicians use to describe symptoms, limited the amount of data this approach could handle. Now, large language models like GPT or Gemini have enabled the systematic analysis of social media posts at an unprecedented scale. "Large language models have made it possible to do this kind of analysis much faster with a level of standardization that could be difficult to achieve before," says Sehgal. Unreported symptomsWhile the population the researchers studied is admittedly not representative—Reddit users are younger, more likely to be male and disproportionately based in the United States—the symptoms described in their collective accounts largely match the known side effects of semaglutide and tirzepatide: about 44% of users in the study described at least one side effect, most commonly some form of gastrointestinal distress. What stood out was the nontrivial percentage of users who reported symptoms that may not be fully reflected in current drug labeling or routine adverse-event reporting. Nearly 4% of users who reported side effects described reproductive symptoms, including menstrual changes such as intermenstrual bleeding, heavy bleeding, and irregular cycles. Others reported temperature-related complaints, such as chills, feeling cold, hot flashes, and fever-like symptoms. In addition, fatigue ranked as the second most common complaint among Reddit users, despite reaching reporting thresholds in relatively few clinical trials. "These drugs are thought to work by engaging part of the brain called the hypothalamus, which helps regulate a wide variety of hormones," says Jena Shaw Tronieri, Senior Research Investigator at Penn's Center for Weight and Eating Disorders and a co-author of the study. "That doesn't mean the medications are necessarily causing these symptoms, but it could suggest that reports of menstrual changes and body temperature fluctuations are worth studying more systematically." Future directionsIn the near term, the researchers hope their findings will encourage clinicians and researchers to take a closer look at the side effects patients are discussing online. "They're clearly on patients' minds, and that's worth paying attention to," says Sehgal. The team also hopes to expand the work beyond Reddit and beyond English-language communities to test whether the same patterns appear across different platforms and populations. "We don't really know yet whether what we're seeing on Reddit reflects the experience of GLP-1 users globally, or whether it's particular to the kind of person who posts on Reddit in the United States," Ungar says. Ultimately, the researchers believe this kind of rapid, AI-assisted social media analysis could become a useful way to spot early warning signs around emerging drugs and wellness trends. For substances that trend quickly online, especially those sold in loosely regulated or unregulated markets, like injectable peptides, patient discussions on platforms like Reddit and TikTok may offer one of the earliest clues to what users are actually experiencing. "The whole point of this kind of approach is that it can move quickly, and that's exactly when it's most valuable," says Guntuku. ARTICLE SOURCE: https://medicalxpress.com/news/2026-04-ai-scans-reddit-flag-overlooked.html
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Man who lost six stone on Mounjaro warns of ‘horrible’ side effects no one mentioned
Antony Hawman was able to completely transform his body – but it wasn't without unpleasant side effects
A man has opened up on the brutal side effects he experienced while losing six stone on Mounjaro.
When combined with dietary changes and an active lifestyle, GLP-1 and GIP receptor drugs have allowed people who previously struggled with their weight to completely transform their bodies.
It was these viral success stories which led Antony Hawman to start using the medication.
"I decided I wanted to be healthier, which was the main aim," the 48-year-old, who is 6'1" and weighed 123kg (19.5 stone) at his heaviest, said.
Antony's decision to use the drug wasn't only physical, as he also struggled with intense food cravings, adding: "I would think about food all the time, and I’d use it as a crutch: if I was sad, I’d eat, if I was happy, I’d reward myself with food."
The 48-year-old weighed 123kg (19.5 stone) at his heaviest (Cover Images)
So when you factor in that Mounjaro slows down your digestion and can reportedly quieten the 'food noise', it seemed like a no-brainer for Antony.
The medication would provide major results for the business owner, allowing him to lose nearly 40kg (six stone) and go from an XL or XXL in July 2024. Antony is now a medium and wears a size 30 or 32 waist.
However, it wasn't without horrible side effects.
'Pretty miserable'
A few months after beginning his Mounjaro journey, Anthony began to experience severe vomiting, diarrhoea and dehydration.
According to Mounjaro manufacturer Eli Lilly, the most common side effects include nausea, diarrhea, vomiting and stomach pain. These symptoms can lead to dehydration and potential kidney problems if not properly treated.
"I moved up to 7.5mgs in my third month and had a pretty miserable weekend of chronic stomach pains, diarrhoea and dehydration," he recalled.
"It wasn’t until I did my research via some chat rooms on TikTok, where a woman in Texas, believe it or not, told me to go back down to 5mgs, get some electrolytes and a decent probiotic and stick with it as long as it was working and then decide whether to move up.
"I definitely felt the messaging was to move up the doses each month and that how it works
"You’d have some side effects and they would pass. I figured out the hard way, that actually, the side effects were pretty grim but if you stick to the lower doses while you are still seeing weight loss and give yourself time to get used to the side effects, the journey was actually fine."
Antony now, after losing six stone on Mounjaro (Cover Images)
'I have completely changed my mindset on food'
Antony reduced his dose and then started taking the probiotic Symprove daily, which has allowed his side effects to completely disappear. Despite the unpleasant side effects, Antony does not regret using Mounjaro and added that he wished he'd found the drug sooner.
"I was on hypertension drugs for hereditary hypertension and have been able to come down to the lowest level of medication from previously being on a cocktail of high doses, which truly is the best outcome," he added.
"As long as you do your research and understand how to nourish your body and take some form of exercise, Mounjaro is an incredible tool, but it’s just that, a tool.
"The best part is I have completely changed my mindset on food. I feel in control instead of it controlling me."
LADbible has contacted Mounjaro manufacturer Eli Lilly for a comment.
What are the other side effects of Mounjaro?
Eli Lilly says the most common side effects of Mounjaro, which affect more than one in 10 people, are nausea, diarrhoea, vomiting, stomach pain and constipation.
Slightly less common side effects include allergic reactions, dizziness, low blood pressure, bloating, burping, flatulence, heartburn, fatigue and gallstones.
Rare side effects include gallbladder infection and changes in taste.
People taking Mounjaro have also complained of the following:
'Mounjaro hair'
One study found that around one in 20 people taking tirzepatide (the active ingredient in Mounjaro) for weight loss experienced hair loss.
Mounjaro can come with side effects (Matthew Horwood/Getty Images)
A Mounjaro user complained on Reddit: "My sister today just did my hair, dyed it and then straightened it after I washed it.
"Right at the end she turned around and said, I think your hair is falling cos you have these big gaps on your head. I asked her to take a photo and I’m horrified."
Superdrug explained: "It’s unlikely that the medication itself is causing hair loss, but the rate at which your body is losing weight causes your hair to shed rapidly.
"Losing weight quickly can be recognised by the body as a form of stress, and research shows this disrupts the normal hair follicle cycle, resulting in hair loss."
Eli Lilly previously told LADbible: "The Mounjaro (tirzepatide) Patient Information Leaflet warns that hair loss is a common side effect. We encourage patients to consult their doctor or other healthcare professional regarding any side effects they may be experiencing and to ensure that they are getting genuine Lilly medicine."
Effect on vision
Popstar Robbie Williams, who said he was taking Mounjaro last year, struggles to see individual faces in the crowd at his shows after a decline in his vision since taking the jabs.
He told The Sun: "I don't believe it's age; I believe it's the jabs."
Robbie Williams complained of vision problems after taking Mounjaro (Grant Buchanan/Dave Benett/Getty Images)
One study looked at nine patients experiencing vision problems after taking semaglutide (the active ingredient in Ozempic and Wegovy) or tirzepatide.
It noted that seven of them suffered a stroke of the optic nerve, which can cause irreversible loss of vision in one or both eyes. The eighth had inflammation of the optic nerve head, and the ninth had a stroke of the retina.
Eli Lilly previously told LADbible: "Patient safety is Lilly’s top priority. We take any report involving patient safety seriously, and actively monitor, evaluate, and report safety information for all our medicines, including Mounjaro (tirzepatide), which is being used to help millions of patients around the world.
"If anyone is experiencing side effects when taking a Lilly medicine, they should consult their doctor or other healthcare professional."
ARTICLE SOURCE: https://www.ladbible.com/news/health/man-mounjaro-six-stone-weight-loss-side-effects-209388-20260305
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