Women are reporting alarming mental health issues after using Mounjaro, a widely used weight-loss injection in the UK. Some individuals describe experiencing sudden panic attacks, intense anxiety, and a bizarre feeling of ‘tugging in the brain’ shortly after starting the medication.
Mounjaro, along with similar drugs like Ozempic and Wegovy, can reportedly help people lose up to 15% of their body weight within a year. In March 2025, around 1.5 million people in Britain utilized weight-loss injections, which many are calling a groundbreaking solution to obesity.
However, an increasing number of users are reporting unanticipated mental health symptoms, including insomnia, tremors, breathlessness, and tinnitus. Although these are not officially recognized side effects of the three main weight-loss injections in the UK, an online support group for affected users has gained over 2,800 members.
Three individuals—who preferred to remain anonymous—shared their experiences with The Times, detailing the severe anxiety and sleeplessness they faced after starting Mounjaro. One mentioned that the anxiety felt like a ‘terror’ unlike anything she had experienced before.
These reports have raised fresh concerns about the safety of these medications as their popularity grows.
Charlotte Lloyd, a 37-year-old social media manager from London, shared her ordeal with severe anxiety that landed her in A&E, according to The Times. After gaining weight during fertility treatment, she qualified for Mounjaro, which was easily accessible through an online doctor service.
Despite initial excitement, her troubles began within days. After her first 2.5mg dose, she quickly lost her appetite and struggled with sleep. After her second dose the following week, she felt everything spiral out of control. She described her desperation: sleeping pills and antihistamines failed to help her get even a moment of rest.
Three days into her symptoms, Charlotte visited A&E, concerned by her continuous racing heart. Although her heart rate was elevated at 105 beats per minute, doctors found no irregularities and sent her home with minimal advice.
Despite her persistent insomnia, her GP was unable to prescribe further help due to regulatory limits. Things deteriorated over the next five weeks, with panic attacks and tremors intensifying. She likened her anxiety to a ‘physical terror’ that felt as though a switch had flipped in her mind.
Eventually, her work performance suffered, leading her to resign, coinciding with the end of a significant relationship. She reflected on her experience, noting the unpredictability of how individuals might react to such drugs.
She added, “If people were aware of the potential for severe mental health side effects, they could make more informed choices.”
Charlotte isn’t alone. Another user, Maria Edwards, also experienced alarming symptoms just 48 hours after her first Mounjaro dose and ended up in the hospital thinking she was having a heart attack. Yet, all tests returned clear results.
Maria remarked that she had never faced mental health issues before but now feels overwhelmed by stress, highlighting an intense sensation referred to as ‘air hunger,’ which makes deep breathing feel impossible. She expressed, “If I had known about Mounjaro’s potential mental health side effects, I would never have tried it.”
A third woman, Julie Peters, aged 31, had a panic attack lasting two hours after two months on the drug and also visited A&E under the impression she might have a heart condition. Tests again revealed no underlying issues, yet she reported symptoms like tremors, the ‘tugging’ sensation in her brain, and persistent tinnitus.
Julie spoke about the heaviness she feels in her brain, which leaves her feeling dull and nauseated. Although her MRI results were normal, she feels uncertain and suffocated by her ongoing condition.
This situation draws attention to a study published last year in the International Journal of Clinical Pharmacy, which linked 481 psychiatric events to weight-loss medications. Researchers stressed the need for more investigation into these potential adverse effects.
While mental health issues like anxiety and insomnia aren’t listed as side effects by the Asda Online Doctor, the clinical team insists that a thorough medical history is essential for approval of these treatments.
The manufacturers of Mounjaro, Eli Lilly, and those of Ozempic and Wegovy, Novo Nordisk, maintain that patient safety is their utmost priority and actively monitor and evaluate safety-related information about their products.
In light of recent findings, there are concerns regarding the possibility of increased risks for depression and suicidal thoughts associated with these medications. Both companies emphasize that their drugs have been evaluated and assessed by the UK’s regulatory body without significant discrepancies noted.
