This time last year I was newly into my Mounjaro journey. Nudging the scales at 13-and-a-half stone, and a size 18, I knew I needed to take drastic action to address my weight.
I dropped 11lb in those first three weeks and today, a year on, I’m 4st down and a comfortable size 10.
I came off the jabs after six months and went on to lose a further stone without them. For me, Mounjaro was a Christmas miracle.
Today, however, and with more than three million people (5 per cent of the population) using them in the UK – and several high-profile celebrities sharing their experiences – we are learning more about their side-effects.
Known clinically as GLP-1s agonists, which work by mimicking our natural satiety hormone to reduce hunger, they appear – now – in some cases – to cause other reactions in the body too: some good, some undeniably alarming.
Indeed, it seems barely a week goes by without the medication being linked to some new response, with ‘foot drop’ being the latest in a range of ‘fat jab’ side-effects.
Giles Yeo, professor of molecular neuroendocrinology at Cambridge University, says: ‘There are always risks to taking drugs, and as millions more take these particular ones, the data will become more defined. Currently it’s limited. What we do know is that around 75 per cent of people will experience no measurable side-effects [on GLP-1s] at all.’
So, if you’re gazing at a post-Christmas midriff and considering the jabs yourself, how seriously should you take the risks, side-effects and benefits – in other words, the good, the bad and the ugly…
A year on from taking Mounjaro for the first time, Claudia Connell has gone from a size 18 to a size 10, having lost four stone
THE GOOD
CANCERS
A retrospective cohort study in the US examined data from over 86,000 patients with obesity over a ten-year period. Half were GLP-1 users, and none had any previous history of cancer.
Data showed those taking the drugs experienced a reduced overall risk of 13 cancers linked to obesity (liver, thyroid, pancreatic, bladder, colorectal, kidney, breast, endometrial, meningioma, upper gastrointestinal, ovarian, multiple myeloma and prostate) as well as lung cancer.
Decreased Risk: Approximately 7 per cent reduction in developing obesity-linked cancers.
DIABETES
Fat jabs hugely reduce the chance of developing new-onset diabetes in pre-diabetics and those with obesity due to the positive effect it has on insulin, coupled with weight loss. Even without loss there is a significant reduction.
Decreased Risk: Average 80 per cent reduced risk of diabetes in obese users.
CARDIOVASCULAR DISEASE
Research presented at this year’s European Society of Cardiology conference showed weight loss injections hugely reduced the chances of people with heart conditions being hospitalised or dying.
Some 90,000 obese heart failure patients with type 2 diabetes were studied – those taking Wegovy were 42 per cent less likely to be hospitalised or die while those on Mounjaro were 58 per cent less likely.
Another study by University College London found those taking Wegovy with a BMI of 27 or higher, and a history of cardiovascular problems, had a 20 per cent reduced risk of heart attack, stroke or death due to cardiovascular disease regardless of their starting weight and the amount they lost.
Decreased Risk: Up to 58 per cent reduced risk of heart attack in those with previous heart failure.
Former politician Nadine Dorries lost three stone on Mounjaro, but confessed in her Daily Mail column that the jabs made her hair fall out and left her with bald patches
REDUCTION IN DRINKING AND SMOKING
A widely reported and unexpected side-effect of fat jabs is growing evidence that, due to the effect they have on reward pathways in the brain, those taking GLP-1 drugs often find themselves cutting down on alcohol and tobacco.
Professor Yeo says: ‘There are no official studies into this but anecdotally doctors are finding that around 50 per cent of their patients on GLP-1 drugs are drinking and smoking less or not at all.’
Decreased Risk: Up to 50 per cent cut in alcohol and tobacco.
ALZHEIMER’S
Danish company Novo Nordisk, the makers of Ozempic and Wegovy, saw its share price drop by 12 per cent last month when data showed the drugs had ‘no significant’ benefit when it came to slowing down the onset of Alzheimer’s.
However, it’s a different story for Liraglutide (sold in the UK as Saxenda). A study by Professor Paul Edison for Imperial College London took 169 patients with mild to moderate Alzheimer’s and gave half Liraglutide and the rest a placebo.
Brain scans after a year showed the GLP-1 drug slowed brain loss volume by half. Those taking the drug also had 18 per cent improvement in cognition.
Decreased Risk: Potential 50 per cent decline in brain cell loss.
THE BAD
FOOT DROP
Also known as ‘slimmer’s paralysis’, foot drop is a rare and temporary condition where rapid weight loss causes the foot to droop, making walking difficult.
Last month orthopaedic surgeon Tim Sinnett reported seeing a ‘handful’ of such cases, stating that he expected the figure to rise.
‘Although losing weight is generally beneficial for the feet and ankles, in terms of reducing the force on the joints, the speed of the weight loss appears to be causing the nerves to malfunction,’ he said.
Cases have been linked to Tirzepatide (Mounjaro) and that’s likely to be because it is the GLP-1 that delivers the fastest weight loss.
Professor Yeo says: ‘I have not heard of foot drop, but it sounds to me that it must be due to loss of lean mass and cannot be considered a drug-specific issue.’
Risk: Negligible.
HAIR LOSS
Data on those experiencing hair loss after taking GLP-1 drugs has been conflicting. Clinical trials by Novo Nordisk found hair loss affects around 10 per cent of users while Eli Lilly (producers of Mounjaro) put the figure at 5.7 per cent.
A study of one million people presented to the European Academy of Dermatology and Venerology found those on GLP-1 drugs had a ‘significantly higher’ risk of developing hair loss.
Experts put this down to rapid weight loss, which puts the body into physiological stress leading to telogen effluvium (shedding). In most cases the hair loss is reversible.
Risk: Up to 10 per cent
Singer Robbie Williams has revealed that he is experiencing blurred vision and blames his use of weight loss injections
IMPAIRED VISION
Singer Robbie Williams recently revealed he is experiencing blurred vision and blames his use of weight-loss injections.
‘I want to warn people to do their research,’ he said. ‘I was an early adopter of the jabs and I’ve noticed that my eyesight’s not good.’
He went on to say he was unable to make out players on a football field and had to change his glasses prescription.
Earlier this year The European Medicines Agency (EMA) recommended updating GLP-1 product information to include NAION (Non-Arteritic Anterior Ischemic Optic Neuropathy), a sudden loss of vision, as a rare side-effect thought to affect one in 10,000 users.
Risk: Negligible.
MALNUTRITION
Fat jab users can expect to lose up to 20 per cent of their body weight. Appetite suppression fluctuates with individuals reducing their calorie intake by anything up to 40 per cent. This can lead to an inadequate intake of protein and micronutrients.
A US study of 461,300 adults on GLP-1s (most with type 2 diabetes) found 12 per cent experienced nutritional deficiencies within six months of use and 22 per cent within 12 months of use. Vitamins A and D are the most commonly deficient, with calcium the most common mineral deficiency.
Risk: Up to 22 per cent in those with diabetes.
Sharon Osbourne, pictured in November with daughter Kelly, has spoken publicly about experiencing significant muscle loss after using Ozempic
MUSCLE MASS LOSS
Our lean muscle mass protects our joints and spine from impact, reduces our risk of falls and keeps our metabolism fired up. A report by medical journal The Lancet looked at data from GLP-1 users and found lean mass loss (fat-free mass) accounted for between 25 to 39 per cent of total weight loss.
Excessive weight loss accompanied by a lack of exercise (particularly resistance training) and poor protein intake are contributory factors.
Muscle loss is due to the effects of weight loss rather than the drugs themselves.
Risk: An average of 30 per cent of total weight lost can be lean mass/muscle.
GALLBLADDER DISEASE
Gallbladder issues including gallstones and inflammation of the gallbladder may increase in some individuals on GLP-1s.
A review of 76 clinical trials found a slightly increased risk of gallbladder disease when fat jabs were taken at high doses for an extended period. Semaglutide (Ozempic and Wegovy) and Liraglutide (Saxenda and Victoza) were found to carry a higher risk than Tirzepatide (Mounjaro).
Professor Yeo says: ‘Some of us are susceptible to gallstones and some are not. If you are susceptible and then you suddenly lose a lot of weight very quickly, making your gallbladder work much harder, then you will be more likely to get stones.’
Risk: 0.8 per cent.
Claudia pictured in the summer, halfway through her weight-loss journey
PANCREATITIS
Data from the MHRA (Medicines and Healthcare Products Regulatory Agency) show 574 reported cases of acute and chronic pancreatitis (sudden inflammation of the pancreas) including fatalities.
It is not known if genetics are a factor in these cases.
The MHRA said: ‘Sometimes genes can influence the side-effects an individual experiences when taking a medicine, so in the context of the increasing usage of these medicines and the reports of acute pancreatitis we have received, we are exploring this further.’
In controlled trials no significant increase has been found of acute pancreatitis in those on GLP-1 drugs compared to those on a placebo. The Mounjaro patient information leaflet lists acute pancreatitis as an ‘uncommon’ side-effect that may affect up to 1 in 100 people.
Risk: 1 per cent.
HEADACHES/MIGRAINE
Since GLP-1 drugs affect multiple systems in the body, including digestion, blood sugar regulation and hydration levels, this can lead to the onset of headaches.
Symptoms are most likely when you’re first introduced to the drugs or with a dose increase.
However, a study by the Headache Centre of the University of Naples on obese long-term migraine sufferers found the drugs to be beneficial. Participants reported that their monthly migraine days were cut by more than half.
Risk: Approx 10 per cent.
OZEMPIC FACE/BODY
So called ‘Ozempic Face’ happens when fat jab users notice increased facial wrinkles (due to fat loss), sunken or dark circles around the eyes, sagging skin around the jaw and neck (jowls) and uneven fat distribution.
Professor Yeo says: ‘We cannot control where we lose weight from – for some it will come from the limbs but for others it will come off the face first. It’s an individual response and not drug-specific.’
Fast weight loss on GLP-1s can also lead to ‘Ozempic boobs’ and ‘Ozempic bum’.
DEATH
The MHRA has so far recorded 111 deaths in the UK as ‘an adverse drug reaction with a fatal outcome’ when GLP-1s were in use.
However, it states that ‘a report does not necessarily mean that a death was caused by the medicine, only that the reporter has a suspicion it may have been’.
Half of those recorded were diabetic which, on its own, places the user in a high-risk category.
Conversely, data shows that those taking GLP-1 have a lower overall risk of all-cause mortality (dying of any cause) since weight loss significantly reduces the chances of heart disease, stroke and obesity-related cancers.
Risk: Negligible.
…AND THE UGLY
Actress and comedian Amy Schumer has spoken openly about experiencing severe nausea and vomiting while taking weight-loss injections, specifically Ozempic and Wegovy
GASTROINTESTINAL PROBLEMS
The most common side-effect experienced by GLP-1 users, and one that can be attributed to the drug rather than weight loss, is an upset stomach which might lead to vomiting (actress Amy Schumer has spoken of her nausea while on a weight-loss drug) or diarrhoea.
Professor Yeo says: ‘The likelihood of these types of side-effects increases with higher doses.’
Many users, after learning which foods they can and can’t tolerate on the medication, will be able to manage and reduce symptoms.
Risk: 20 per cent.
So, if you are overweight, are the risks that come with fat jabs worth it?
‘My view is that if you have a metabolic disease such as diabetes or obesity, then that is always going to be a bigger risk to you in the short, medium and long term than whatever subtle increase in risk for very specific conditions that you may, rarely, get with GLP-1 drugs,’ says Professor Yeo. ‘I believe the pros outweigh the cons quite significantly.’
Main image of Claudia Connell: Photography, Ed Miles; Hair and make-up, Bethany Rich; Styling, Liz Hemmings
