Mounjaro Triggered a Little-Known Side Effect in My Case

I am standing on the crest of a vast hill in the grounds of a grand country house, with Bath’s beautiful skyline stretching out below me.

It is Good Friday in 2025. Pale sunlight is breaking through the clouds, while my husband Simon and I struggle to catch our breath after pushing our double buggy up the sharp incline from the lake, with our two children inside.

We are lucky to live in this city. The scene is peaceful and almost perfect, and at 37, my life appears to be everything I could have hoped for—certainly far more than I imagined just 12 months earlier.

Yet as I look at our children, aged three years and nine months, then turn to Simon, the words come out: ‘I don’t think I can carry on like this.’

I dissolve into tears and tell him I believe he and the children might be better off without me.

The shame is overwhelming. I can barely manage to pretend everything is fine for the sake of my children. My body feels impossibly heavy, my energy has disappeared and all I want is to return home and sleep forever.

Simon starts crying as well. He guides me back towards the car, wraps his arms around me and reminds me that I am deeply loved—not only by him and our children, but by so many people. He begs me to understand how much the children depend on me, and how much he does too.

Nine months after the birth of my second child, I struggle to comprehend how I reached this point. That baby’s first six months had been among the happiest periods of my life.

Only three months earlier, we had celebrated an almost magical first Christmas as a family of four. Simon and I repeatedly caught one another’s eye as we watched the two children we had created, telling each other, ‘We are so lucky’ and ‘Life can’t get much better than this.’

Neither of us said those things casually.

Following the birth of our first son, my mental health collapsed. I was diagnosed with postnatal depression and anxiety, and I had never felt so worthless or reached such a low point.

People who have experienced postnatal mental health problems understand how quickly shame can take hold. When you feel anything other than pure gratitude after having a baby, it can convince you that you are the worst parent in the world.

For me, that guilt was particularly intense. Much of my early thirties had been spent single, longing to become a mother while quietly worrying that it might never happen.

I met Simon, now 38 and working in technology, during the pandemic through a dating app. The connection was immediate, and the love felt unlike anything I had known before.

The fact that we had survived the darkest days of my depression during our first year as parents showed how strong our relationship was. At the same time, the experience left both of us nervous about having another baby.

We planned carefully, putting a strong support system in place in case my mental health deteriorated again.

At first, at least, the preparations seemed to work. The therapy I had undertaken, the progress I had made and our greater confidence as parents meant the early months after our second son’s arrival felt significantly easier and less frightening.

This time, I could access the deep contentment that had been buried beneath terror and panic after my first child was born.

It is not an exaggeration to say I woke up every single day of those first six months feeling so relieved not to be depressed, even while totally exhausted by the task of caring for a two-year-old and a newborn at once.

So why did I sink so low and why so suddenly nine months later?

Well, around the six-month mark, a few days before New Year’s Eve 2024, two big things changed. The first is that I finished breastfeeding and the second is that like hundreds of thousands of other Brits around that time, I started taking tirzepatide, a GLP-1 agonist medication known by the brand name of Mounjaro.

The drugs arrived a few days after all the excesses of Christmas and, bang, within hours my appetite was utterly gone. I could hardly believe it.

I was seemingly very sensitive to the drugs. I’ve since learned that not everyone reacts so drastically, but the pounds just fell off.

I was euphoric for three weeks after I started taking them, then things began to go horribly wrong.

One minute I was fine – a happy, tired mum catching up with friends in my kitchen – the next, I’d feel my thoughts cloud over and everything turn dark.

I was at a coffee morning with my friends when I first noticed something wasn’t quite right. I became completely disconnected from my surroundings. As it got worse, I began to feel terrified. My heart rate went through the roof and sweat dripped from every pore.

I called Simon, who was at work, to come home immediately because I was sure something was seriously wrong.

Worried, I contacted the pharmacy that had prescribed the GLP-1 and it suggested I swap to Wegovy instead. Which I duly did. But rather than getting any better, I began to deteriorate even more.

I started reading around the side-effects of weight-loss drugs and discovered that some patients taking Wegovy had reported ‘suicidal ideation’ as a reaction to taking the medication. Could this be happening to me? The problem was, no one really knew.

It was so new to the market back in the first half of 2025, it felt like I was part of a mass human drug trial. No one – from the pharmacist to my GP – could give me answers beyond ‘just stop taking it’. Which is exactly what I did.

I told myself that Simon and my babies needed me to be well and I couldn’t take a risk on anything that might risk my mental health – even for the sake of losing the 15kg (2st 5lb) that I’d put on after the birth of my second son, a weight gain that was also making me miserable.

The fact is I have struggled with my body image all my life. The perception of my weight as bad and wrong has been constant and relentless since the age of seven. Those feelings of shame are difficult to shake.

It wasn’t just me who had a problem with my weight, it was other people. It didn’t matter if they loved me, their words hurt – and many would be mortified to find out how much.

There was the family member who told me that my legs shouldn’t rub together when I walked while wearing a pair of much-loved CK Jeans shorts. I was ten and I never wore them again.

The GP who advised my parents they should take me to Slimming World meetings aged 15 (where, incidentally, a well-meaning woman told me they’d get me ‘skinny in no time’ – I was a size 12).

The best friend I made at university who told me – in a way that sounded like she thought it was a compliment – her friends visiting from home thought that I had ‘such a pretty face’, I’d be a ten-out-of-ten if I lost weight.

The drunken boss who told my colleagues at a Christmas party I had the ‘best t**s in the office’ and what a shame I didn’t have the body to match.

The boyfriend who told me he loved my curves before threatening to leave me if I didn’t lose weight.

The friends and family members who repeatedly told me when I did lose weight at the age of 28 – at which point I had an incipient eating disorder – that the boyfriend had ‘done me a favour’ with his threats because I looked the best I ever had.

And more. So many more.

In isolation each of these moments stung a lot, but I was able to move past them. Taken together, they added up to a concerted attack on my self-esteem, my sense of identity and my confidence in the world.

So when I thought I’d finally found the answer in GLP-1s to years of anguish about my weight, it was a considerable blow to have to come off them.

Soon after the drug left my system, however, my thoughts calmed considerably. Coupled with a month of therapy, the dark clouds lifted. I began to feel well again.

With the energy I needed to be the mother I always wanted to be, I swore that I would never, ever go back on the jabs…

So why, one year later, am I back on them again? How unwise would you have to be to take something you strongly suspect gives your mental health such a kicking?

Only a fool, and a hypocrite, would prioritise weightloss over the stability of their life and family, surely?

Once the post-birth rollercoaster settled and my hormones calmed down, I went back to work as a freelance journalist. I felt stronger. But I couldn’t lose the weight.

I went to the gym five times a week and both Simon and I started eating a much better diet. But although I was trying really hard, the baby weight stubbornly refused to shift.

So in May this year, going against the guidance from the online pharmacist and taking just half of the starting dose – a tiny measure that on most people would have little effect – I started on the jabs again.

I pledged that if I was going to take the risk on Mounjaro I would take measures to protect myself.

Simon was wary but supportive. He knew how important it was to me.

I also enlisted the help of my friend, the head nutritionist at the health company Zoe, Dr Federica Amati, whose book The Appetite Reset explains how to plan for life before, on and after GLP-1 medication.

This time around I have alarms set on my phone to remind me to eat protein and fibre, such as scrambled eggs and smoothies packed with vegetables.

I keep track of everything I eat to make sure I’m hitting my goals and consuming the right nutrients.

All of which means that this time, my experience has been totally different. I don’t feel like I’ve been run over by a freight train and my appetite, though much diminished, hasn’t turned to ashes and nausea.

It’s true that my progress is slower, but I don’t have the fear I felt the first time.

I won’t lie and say I don’t have anxious moments. I always find my heart rate increases for a day or so after I inject, which tends to make me feel jumpy – like I’ve had too many coffees. But now I know this is normal and I’m no longer afraid of it.

I don’t know how much weight I’ve lost because I haven’t been weighing myself. I know how easy it is to become obsessed. But my clothes fit better. I’m a size 18-20 now and I certainly feel healthier.

I’ve kept up my strength training and the body scan they do at the gym has told me I’ve lost fat rather than muscle.

I have so much more energy because my mental health is better and I’m not consumed by shame about my body.

Even though for some people my current size would be a nightmare, for me it’s great.

I know I never want to go back to the darkness and fear I felt when I first took the jabs. And some might say I’m crazy to tempt fate. But, for now at least, I am proud of myself for finding a way through that has worked.

Rose’s new podcast, A Matter of Fat, co-hosted with obesity expert, Professor Giles Yeo MBE is out now