'Game-changer': Semaglutide promises to avoid weight loss pills troubled history, but do they work?
With more and more people living with obesity, finding an effective and safe drug to aid weight loss is something that scientists have been questing for over half a century.
In the past, drugs approved for weight loss have had a troubled history, with several withdrawn because of serious side effects.
Now a drug called semaglutide (also known as Wegovy) - described by some experts as a "game-changer" - is being considered by NHS watchdog NICE for use in the NHS, with a final decision about how it'll be rolled out next month.
The results from a trial of just under 2000 people funded by Novo Nordisk, the manufacturer of Wegovy, look like a promising first step, with average weight loss being around 15%.
It shows that people lost more weight with semaglutide alongside supervised weight loss coaching than those on the trial who relied on support alone.
Taken by weekly injection, the drug is effectively a modified gut hormone.
Natural hormones are released in the gut when we eat, which informs the body and the brain that we're full. Semaglutide works in the same way.
But it lasts longer in the body, reducing our appetite over time.
NICE's current recommendations for the drug are that, with a few exceptions, only adults living with obesity with a BMI of at least 35 and one weight-related health condition can qualify for it.
But under current plans, it won't be as simple as popping to your GP to ask for a prescription. And those looking to buy the drug online may not get the desired effects.
Professor Barbara McGowan, a consultant endocrinologist and one of the scientists who led the trial, was surprised by the big weight loss effects of the drug.
"We've never seen that before with one medication," she says.
But simply getting a prescription will not be enough. The lifestyle changes in the trial were a key part of treatment.
"They [trial participants] were advised to reduce their calorie intake by 500 calories per day, as well as exercise, 150 minutes per week. So about 30 minutes per day, for five days," she says. Healthcare professionals were also checking in - which may also impact weight loss.
In the NHS in England and Wales, current plans for the drug are to be prescribed for two years as part of specialist weight loss management services - so-called tier-three services.
But local areas decide what they will offer patients and these services are not available everywhere.
Dr Stephanie De Giorgio is a GP in Kent. She has written papers on weight loss funded by Novo Nordisk. She says the drugs are a useful tool but says they're not going to be suitable for everyone and have to be prescribed by people who understand them. She is, however, critical of the patchy nature of weight management services.
"It's massively variable across the whole country and that's just not okay that wouldn't be okay with cancer. It wouldn't be okay with heart disease and yet it's considered okay with this," she says.
This week, the government announced that it is reducing funding for weight management services by £100million. It says it needs to balance the books to pay for its living with covid strategy - such as targeted vaccination and testing ongoing pandemic surveillance.
There are still some unknowns with semaglutide - such as what happens after two years of taking it, including its long term effectiveness in keeping weight off and if there is a reduction in any illnesses associated with obesity.
Some on the trial re-gained weight once the study was over. And, in some cases, there were side effects, including nausea, gastrointestinal problems, gallstones and acute pancreatitis.
Mr Ahmed Ahmed, a bariatric surgeon in London, prescribes drugs to help weight loss and suggests none so far have made any significant impact on obesity rates.
"We are all excited about semaglutide, and we really hope that it's going to make a big difference, but that remains to be seen," he says.
"Surgery offers the most significant weight loss and also the most long term and sustained weight loss than any other treatment," he says.
We do not know how semaglutide compares to bariatric surgery in either the short or long term.
But bariatric surgery is invasive, and access is limited. In the UK, there are 6,000 operations a year compared to France, where it is estimated they carry out 60,000.
Mr Ahmed has received public funding to conduct a less invasive trial. It involves sending hormones into the top of the stomach via a catheter.
"What we think is going to happen when you block the blood supply to that part of the stomach is that the grenin levels will drop. And your hunger levels, as a consequence, will reduce," Mr Ahmed says.
But the trial is only in its early stages, and there's much to learn about its effectiveness.
Medical and surgical interventions are only part of the solution.
Weight management specialist suggests 'neither medication nor surgery alone can address' obesity
Professor Paul Gately, an obesity and exercise specialist, runs a weight management service and says some of his patients have highly complex needs, which neither medication nor surgery alone can address.
"We know people need that sort of social, mental health support, and some physical help around their diet, around their physical activity," he says.
And some experts say putting all our hope in medical or surgical interventions detracts from focusing on how the world around us impacts our weight. Obesity is an immensely complex health problem, often with root causes in people's social environment and poverty.
Since the 1990s, successive governments have launched 14 separate strategies to tackle obesity with mixed success.
Dr Greg Fell, director of Public Health in Sheffield, says the answer lies in the environment.
"Whilst I will say…that we need to be personally responsible. We make choices in an environment. The environment is loaded towards helping us make the wrong choices,"
"It requires government intervention to change the environments in which we make choices."
Professor McGowan also says we need to think more broadly too.
"It's [semaglutide] not going to be a magic bullet. We need to also change our environment, our physical activity. You know, we need to look at government policies," she says, adding: "We need to tackle obesity in so many different ways. So I don't think that just one intervention is going to do it. It would be far too simple."
You can watch Fighting fat: A cure for obesity? on ITV on Thursday at 8.30pm or on the ITV Hub.
If you have been affected by issues raised in this article, for more information and support, you can go to:
Samaritans can be visited at their website or called on 116 123 for free if you need support with any on-going mental health problem.
The Mental Health Foundation can provide more information on preventative mental health support.
And, Mind provide resources to people currently dealing with a mental health problem.