I STARTED TAKING MOUNJARO IN MY 50S – IT WORKED, BUT LEFT ME EXHAUSTED

My weight has always been the one thing I had felt in control of, since I was a teenager. All it took was a little willpower, even after two pregnancies, and the pounds generally dropped relatively easily.

But something changed in my late 40s. The Covid lockdown meant that, despite my best efforts, my lifestyle was less active. And then I went through the menopause and became a carer to an elderly mother, all within the space of a few years. Somewhere amid that emotional and physical upheaval, I piled on two extra stone, which has stubbornly refused to budge.

My 50-plus health check earlier this January proved to be a wake-up call: I was officially obese, with a BMI of just over 30. With two people in my immediate family with Type 2 diabetes, I knew I needed to do something drastic.

In the meantime, I was seeing friends lose weight very rapidly on weight loss (GLP-1) medication, the most popular of which is tirzepatide, more commonly known by its brand name Mounjaro, which is administered by weekly injection. The drug works by slowing the movement of food through the digestive system, causing the pancreas to release more insulin and lowering the amount of blood sugar produced.

While weight-loss medication can now be prescribed by GPs on the NHS, in the first phase of its roll-out, it is only available to people with a BMI of 40 or over, who meet four out of five weight-related conditions including Type 2 diabetes, high blood pressure, and heart and vascular disease. Anyone who meets these requirements is also entitled to additional medical support including advice on exercise and heathy eating, as well as regular check-ups.

This initial roll-out is expected to reach around 220,000 people, and while the intention is to make the medication more widely available, I don’t currently meet the requisite criteria.

Buying the drugs from a private provider is my only option, and I had a lot of concerns about doing so. What if I needed follow-up? Who would be monitoring me? It felt too risky.

But, after yet more failed diets, including variations on intermittent fasting, it was when my local pharmacist started stocking Mounjaro that I finally relented. I was offered a face-to-face consultation, my BMI was checked, and my progress is being monitored.

I had my first jab about three weeks ago and have lost about 5lb in that time.

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While Mounjaro is sometimes seen as a miracle drug, it still requires a calorie-controlled diet to be followed. However, for me, the medication has made it a lot easier to do so, as the continual “food noise”, has completely disappeared.

In the first few days on the jab, I had to remind myself to eat. Often, I would prefer fluids, such as protein shakes, water and iced coffee, to solids, in addition to one regular meal.

But the appetite suppression has come at an unexpected cost. While my concern before taking the jabs was that I would suffer the same upset stomach, nausea and vomiting that has been widely reported, my biggest side effect in the first two weeks of the jab was complete and utter exhaustion. My usual twice-weekly weight training sessions at the gym have left me feeling wiped out for the rest of the day.

Dr Duane Mellor, a registered dietician and spokesperson for the British Dietician Association, explains that fatigue is a common symptom of any weight-loss approach, whether that’s with drugs or without them. “It’s a normal biological process, because our bodies are designed to try and conserve energy. So, by feeling tired you tend to reduce any voluntary activity,” he says.

When it comes to Mounjaro and other weight loss injections, Mellor notes that appetite suppression could lead to a reduced intake of important nutrients, which can also have an impact on energy levels. “We know, anecdotally, from practice, that without careful support and thought about diet quality, you can just replace a healthy diet with small amounts of a less healthy diet, which could then, lead to a risk of low intake of key nutrients such as protein, iron and B12.”

“There is an increasing body of thought that we need to think about supplementation in the same way as we do with some forms of weight loss surgery,” adds Dr Mellor.

Perimenopause and menopause doctor Shahzadi Harper adds that for women in midlife such as me, fatigue can be common. “I will always do blood tests to eliminate other causes of their symptoms, including checking that they haven’t got an underactive thyroid. But sometimes there can be an unexplained fatigue, because women’s hormones, in particular their oestrogen, levels are decreasing. Testosterone also drops and can make them less energetic too.”

Dr Harper as part of her menopause and perimenopause management programmes. “I always explain to patients that they may feel tired, nauseous or even cold, because their body is fighting the Mounjaro,” she explains. “Our body has a ‘set point’ and when it feels that you are starving it, it wants to keep your weight at that point.”

Speaking to experts has helped me to better understand the importance of taking a holistic approach to weight-loss drugs. I have since had full blood tests carried out with my GP to test for B12, iron and vitamin D, and was relieved when these all came back in the normal range.

For those who don’t have access to specialist nutritional support, Dr Mellor suggests a supplement that has 100 per cent of the recommended daily amount of B12 and iron, and if they are still feeling symptoms of fatigue. that you see your healthcare professional for a blood test to check levels of both.

As I come to the end of my first month on the jabs, one concern that has been playing on my mind is how I will keep the weight off once I have stopped them.

Dr Jack Mosley, GLP-1 expert and author of Food Noise, addresses this in his book. “I was following the progress of these medications, and I could see that they were an incredible breakthrough in weight loss. However, it was becoming clear to me that people are not being provided with that much information with how the drugs work, their side effects and how to manage them, and the importance of following a nutritious lifestyle,” he explains.

“These are incredible drugs, but if people don’t change what they eat while they are on them, and they don’t change their lifestyle, then once they stop them, they are very likely to put the weight back on.”

And it’s not just nutrition, but physical activity that has to change. “There is some suggestion that weight loss with these drugs might lead to more muscle loss than other weight loss methods. So, maintaining strength work as part of your physical activity will be important,” says Dr Mellor.

Light exercise may in fact also help to reduce fatigue better than rest, notes Jack McNamara, a senior lecturer in clinical exercise physiology at the University of East London. “Begin with just 10 to 15 minutes daily and gradually increase,” he says. “Morning workouts tend to be easier, before fatigue peaks.”

“The bottom line is that these medications work with your body’s natural processes, not against them,” adds Mr McNamara. “Exercise amplifies their benefits while reducing the risk of regaining weight when you eventually stop the medication.”

I went down the weight-loss medication route with quite a lot of scepticism about whether it would work, frustration with myself at not being able to lose the weight without medication, and concern about the longer-term impact.

For now, the initial exhaustion seems to have passed, and I have adjusted my exercise routine to allow for it, as well as incorporating nutrient dense foods in my diet, including protein and greens. While the weight has been slow in coming off, it is shifting gradually. It’s so refreshing not to be thinking about food all the time, and I am planning on staying Mounjaro for another month or so at least, in the hope that I can reach a healthier weight.

2025-06-26T05:21:55Z