It’s being hailed as a ‘miracle drug’ for burning fat and a breakthrough in the war on obesity, but users of Mounjaro have uncovered another unpleasant side effect.
Despite their undeniable slimming effects, injections of GLP-1 drugs, such as Ozempic and Wegovy, have been linked to a range of side effects, including muscle loss, hair loss and ‘Ozempic face’.
Now users of the slimming drug tirzepatide, sold under the name Mounjaro and also called the ‘King Kong’ of slimming injections, are complaining that the drug is giving them a permanently ‘freezing’ cold.
Dozens of TikTok users have shared clips showcasing their drug-induced chills, tagging the videos with the hashtag “jaro jitters” and “Mounjaro side effects.”
A recent TikTok video posted by @katie.k1986who has been using the drug for just over a month, the social media user is seen wrapped in a fleece as she tells her followers she is ‘so cold I could be in Greenland’.
Several TikTok users commented on the video, echoing Katie’s experience.
“I’m watching this video under an electric blanket,” said one, while another wished the menopause had started to raise her body temperature.
Another video posted by @life.withleannewho has been injecting Mounjaro for almost six months, is seeing the suggestion emerging on social media that Eskimos are warmer than them.
Social media user @nicinackinoo (photo left) complained about the side effect. She said, “I’m wearing a granny nightgown, a dressing gown, a throw and another throw and socks and I’m still shivering.” In a video posted by @life.withleanne (pictured right) you see her confess that there are ‘Eskimos warmer’ than her
Meanwhile user @nicinackinoo said, “I’m wearing a granny nightgown, a robe, a throw and another throw and socks and I’m still shivering.”
Now Professor Alex Miras, leading obesity expert from the University of Ulster, has provided a simple explanation for the phenomenon.
He explained that when we lose weight, our energy expenditure decreases in an attempt to preserve fat – meaning we burn fewer calories.
But the process of burning energy generates heat, which means we get colder if our bodies do this less often.
Professor Miras told MailOnline: ‘When people reach their weight plateau, which is usually a year after starting the medication, they burn more energy and are less likely to complain about being cold.’
Professor John Wilding, an expert in cardiovascular and metabolic medicine at the University of Liverpool, said feeling cold is simply the result of losing fat.
He told MailOnline: ‘People who lose weight will have less fat, and because this acts as an insulator it might make sense that they feel the cold more; there is also a slight slowdown in your energy consumption.
‘It is known that cold intolerance can occur with weight loss, whether this is done through diet, medication or weight loss surgery.
‘So if people experience this, it is probably due to the weight loss and not due to a specific effect of the medication used.’
Experts say that the side effect of feeling cold while taking Mounjaro is simply a result of losing fat and thus insulating the body.
Like many medications, Mounjaro’s side effects can be serious and more than 100 deaths have been recorded since 2023
Clinical trials have reported a number of side effects with the use of Mounjaro.
One study, involving 900 participants, found that a fifth experienced nausea and diarrhea, and about one in ten reported vomiting or constipation.
US pharmaceutical giant Eli Lilly, which makes the drug, said side effects of Mounjaro were most commonly reported when the dose was increased.
Only about 4 percent and 7.5 percent of participants, in the 10 mg and 15 mg dose cohorts, respectively, discontinued the study due to side effects.
Other people who used the drug outside of clinical trials have reported experiencing hair loss while taking Mounjaro.
Europe’s medicines watchdog, the European Medicines Agency (EMA), said earlier this year that research in rodents has suggested that the artificial hormones packed into tirzepatide could increase the risk of medullary thyroid cancer.
The EMA has ruled that a monitoring study of patients taking the drug is needed to investigate the potential for an increased risk of cancer in humans.
Some users have also noted that GLP-1 drugs cause premature aging.
That’s because weight loss injections don’t specifically target fat, but rather trigger weight loss by influencing appetite.
As a result, patients can also lose muscle mass by not eating as much protein, the building block of muscle, as they did before taking the drug.
Fat also falls off the face, not just the stomach, which gives many people a thin look, also known as “Ozempic face.”
Because the fat in our faces gives us smooth, plump cheeks and wrinkle-free foreheads, losing it quickly can quickly make people look much older.
However, as with many medicines, Mounjaro’s side effects can be serious.
Susan McGowan, a 58-year-old nurse from Lanarkshire, died of multiple organ failure, septic shock and pancreatitis after taking two low-dose injections of tirzepatide.
She took the shots over a two-week period before her death on September 4. It would be the first time the drug has been listed as a contributing factor on a death certificate.
In another case, Meredith Hotchkiss, a nurse from Meridian, Idaho in the US, said she will now likely be tube-fed for the rest of her life after having the injection for just a few weeks.
The 56-year-old who said the jab had ‘ruined’ her life is one of hundreds of patients who have joined a US lawsuit against the drugmakers of Mounjaro and another slimming jab Ozempic.
Thousands more patients who also suffer extreme side effects are expected to join the legal action as it progresses, lawyers say.