Would you inject yourself once a week to lose weight?

Three years ago, Alex Guevara, a 47-year-old paramedic practitioner based in Milton Keynes, decided that it was time to take drastic action to address his spiralling weight.

“I was very large and very unwell,” says Guevara. “Most paramedics are overweight. It’s an awful job – mentally, physically and emotionally – and lifestyle and environment are everything when it comes to obesity. I had sleep apnoea, severe depression and bad asthma.”

Guevara had heard about an emerging class of anti-obesity medications. These were regular injections containing versions of a hormone called GLP-1, which acts on the brain to create a feeling of fullness and dissuade us from eating. He decided to pay for a private prescription of Ozempic, a drug which provides a form of the GLP-1 hormone called semaglutide.

Like many, Guevara experienced swift and dramatic results, losing four stone. “It was completely life changing,” he says. “All those health conditions resolved.”

Since then, the profile of anti-obesity drugs has soared. Last year, the National Institute of Health and Care Excellence (NICE) made the landmark decision to make another semaglutide drug called Wegovy, available on the NHS to the most overweight patients, defined as those with a body mass index over 35, who also have at least one weight-related health condition.

Manufactured by the Danish pharma company Novo Nordisk, which also makes Ozempic, Wegovy has yielded impressive results in clinical trials. In a study known as STEP 1, more than half of participants lost at least 10 per cent of their body weight after six months. This month, Jeremy Clarkson revealed he has been taking Ozempic in order to prevent diabetes. Last year, Elon Musk even publicly credited Wegovy for his recent chiselled appearance.

More weight-loss drugs are on the way. Pfizer and AstraZeneca have their own products in development, while American pharma company Eli Lilly is waiting to see if NICE approve its drug tirzepatide, which is also based on GLP-1. Last year, a clinical trial suggested that tirzepatide may be even more effective than Wegovy with nearly two thirds of participants losing 20 per cent of their body weight on average.

With obesity rates spiralling in the UK, many specialists have welcomed the arrival of these products. Some 28 per cent of adults are now categorised as obese, placing them at an increased risk of diabetes, cardiovascular disease and some cancers. “These new therapies are hugely important for patients as they provide a choice of options for medical treatment of severe obesity that was previously lacking,” says Professor Akheel Syed, consultant endocrinologist at the Salford Royal NHS Foundation University Teaching Trust.

For while bariatric surgery – which makes your stomach smaller, meaning you feel full with less food – has long been one of the gold standard solutions for tackling obesity, it is not always appealing to patients, and can lead to complications. Specialists also point out that the NHS simply does not have the capacity to offer the procedure to everyone who meets the criteria.

“At the moment the NHS is only doing about 5,000-6,000 of those operations a year, and we probably have more than a million people who would be eligible,” says Professor John Wilding, a cardiovascular and metabolic medicine expert at the University of Liverpool who ran the pivotal STEP trial for Wegovy. “We're never going to get through that lot in a thousand years at the current rate, so we have to think about what other options are available.”

But anti-obesity drugs also come with their own costs. The field of weight-loss medicines has long been ridden with safety issues, from popular diet pill phentermine (which can cause heart palpitations, high blood pressure and insomnia) to lorcaserin (a drug once touted as “the holy grail” in the fight against obesity until regulators pulled it from the market in 2020 over fears that it increased cancer risk).

The newer drugs also come with their own, not-insignificant issues. Facebook groups show that users of GLP-1-based medications like Ozempic, Wegovy and tirzepatide regularly complain of prolonged morning sickness. Guevara says that, when using Ozempic, he experienced nausea, bowel changes and heartburn. In rare cases, users may even carry risk of pancreatitis, acute kidney injury and anxiety: one trial participant developed panic attacks after stopping Wegovy. A heightened risk of thyroid cancer has been seen in lab animals.

Such risks have provoked concerns. Suzanne Robotti, a consumer representative on the US Food and Drug Administration (FDA) advisory panel, posted a blog where she described her concerns about Wegovy being approved for weight loss, calling the side effect profile “scary”.

Novo Nordisk representatives told the Telegraph that semaglutide drugs had a “consistent safety profile”, and the most common side effects seen in clinical trials were mild-to-moderate gastrointestinal events.

Unknown factors

However, others question whether we know enough yet about these medications in a wider population, especially over a longer timeframe. “The clinical trials evaluating these drugs will have strict inclusion and exclusion criteria,” says Andrew Hill, a pharmacological researcher at the University of Liverpool. “In a real-life setting, there could be people who do not tolerate these drugs as well. The clinical trials of anti-obesity drugs also typically only run for 18-to-24 months, but people could need to stay on them for years to maintain a low weight.”

At the moment Wegovy can only be prescribed on the NHS for two years, but Ozempic can be purchased privately on an ongoing basis. An additional concern is that temporary use of the drugs could encourage weight cycling, a process where individuals repeatedly lose and then regain weight in a continuous pattern which has been linked to a heightened risk of mental health problems.

Novo Nordisk says that it advises patients to follow a reduced-calorie diet and a plan of increased physical activity when ceasing injections, while proponents of the drugs point out that remaining obese has its own health risks, from heart disease to stroke, type 2 diabetes and several types of cancer. “There’s still a lot of debate among obesity experts as to whether you’re better to at least be a lower weight for at least some of the time, rather than none of the time,” says Wilding.

Short-term fix

But while GLP-1 drugs are undoubtedly effective at achieving weight loss, psychologists have questioned whether turning to them is simply ignoring the factors within our society which are driving the obesity epidemic, from the obesogenic food environment to inadequate social support systems.

Eleanor Bryant, associate professor in health and eating behaviour psychology at the University of Bradford, described them as a “short-term, surface-level fix”, and that psychological support remains “highly neglected” in obesity management.

“The underlying problematic behaviours, patterns and issues which are leading to obesity, are not being addressed,” she says. “Using the drugs alone will not teach an individual how to regulate their own eating behaviour in a healthy way, meaning they will be back to square one when their body acclimatises to the drug.”

With the NHS choosing to invest heavily in pharmacological solutions, questions are also being raised about how closely the pharmaceutical industry is entwined with UK obesity care. Novo Nordisk has employed leading UK obesity specialists as consultants as well as sponsoring a variety of initiatives and programmes across both the Association for the Study of Obesity as well as the Obesity Specialist Group of the British Dietetic Association.

The company is also paying £154,299 towards a new GP Obesity Leadership Programme, in partnership with the Royal College of GPs (RCGP), with the aim of developing a national network of GPs which ensures “key insights into best practice are shared at both local and national levels”.

Martin Marshall, chair of the RCGP, told the Telegraph that the programme content is decided entirely by the RCGP, while Novo Nordisk supplied a statement saying that its collaborations with healthcare professionals and authorities are strictly regulated.

However Nicholas DeVito, a researcher working in health policy and transparency at the University of Oxford, said that there could be a potential for conflict of interest. If the programme happened to cover pharmaceutical interventions in obesity care, it would likely result in more GPs prescribing anti-obesity drugs to their patients.

“Maybe the RCGP has some guardrails in place for this kind of industry collaboration, but big educational programmes like that can act as somewhat sneaky vectors of influence,” he says. “You’re providing a service, ostensibly some kind of educational initiative, dressed up in goodwill, that just so happens to focus on your products. A real win-win for the company.”

While academics have their concerns, the anti-obesity drug market is only going to get bigger. Novo Nordisk is already working on an oral version of semaglutide, as well as investigating a combination therapy of semaglutide with another weight-lowering compound called cagrilintide.

From Guevara’s perspective, the rise of such medications can only be a positive development. He subsequently regained a stone and a half, after stopping Ozempic due to the cost of paying £150 per week for a private prescription, but is now back on the drug and looking to shed further pounds with the help of a low-calorie diet. Such is his belief that they represent the way forward for treating obesity that he has since set up Facebook groups which now provide support for around 150,000 people attempting to lose weight with semaglutide.

“In my view, no one who actually understands these medications currently has any concerns about their risk-versus-benefit profile,” he says. “Losing 10 per cent of your body weight is sufficient to avoid diabetes and all its horrors down the line, as well as the 13 obesity-related cancers. Almost everyone I have spoken to, unanimously says that they will take the theoretical risks in order to be healthier right now.”