Are weight loss jabs like Mounjaro and Wegovy still the answer to Britain's obesity crisis?

The NHS drive to rollout weight loss jabs is being questioned after what is believed to be the first confirmed death linked to the drugs.

Nurse Susan McGowan, 58, took two injections of Mounjaro - one of a new generation appetite suppressing drugs being prescribed for obesity - . In recent years I have covered numerous medical conferences around the world at which were presented new trial results showing the remarkable weight loss power of these DIY weekly or fortnightly injections. Known as GLP-1 agonists, Mounjaro, Wegovy and Ozempic slow digestion and reduce appetite by mimicking hormones which regulate hunger and feelings of fullness. They are designed to act like one of these hormones, known as glucagon-like peptide 1 (GLP-1).

Experts were amazed when Mounjaro, also known by its proper name tirzepatide, helped users lose a fifth of their body weight in trials and outperformed previous jabs. Now ever more powerful versions of these drugs are in the research pipeline.

But having spoken to dozens of leading experts on GLP-1s, it is clear they come with an element of risk. Firstly, like all drugs, there is the risk of side effects. The vast, vast majority of these side effects are not life threatening but are just very unpleasant. They can include nausea, vomiting, diarrhoea, constipation, stomach pain, bloating, flatulence, heartburn and indigestion.

Don’t take my word for it, take that of our esteemed ex-Prime Minister Boris Johnson, who admitted taking Ozempic and “losing four or five pounds a week” before “it started to go wrong”. Uncontrollable vomiting meant he had to stop taking it. More recently Tory leadership loser Robert Jenrick also admitted taking Ozempic for weight loss but said he "didn't particularly enjoy it" and gave up.

The problem is, even if you lose a lot of weight, simply taking these drugs is not a long term solution. Alongside this has to come drastic changes to your lifestyle which usually require some serious support. People who are dangerously overweight usually have eating and activity habits which are seriously ingrained since childhood. They require coaching support to develop a different relationship with food.

If done correctly, users can ditch processed junk food and develop a passion for home cooking tasty dishes using whole foods - all while the GLP-1s discourage them from overeating. As they shed the pounds users can regain the confidence to do exercise; be it walking, running, or joining a gym or sports team. There is some evidence to suggest that the dosage of GLP-1 drugs can then be tapered down and some users can even come off them altogether. This is all a best case scenario.

The problem is that without this tailored support from clinicians and dietary experts then users of GLP-1s do not tend to transform their lifestyles. They simply eat less of the poor diet they have always ate.

Users will still lose a lot of weight initially - but importantly they lose muscle mass as well as fat. If they stop the injections because the side effects become too much, or they can no longer afford what is an expensive treatment, then they pile the fat back on. But muscle muscle mass does not return. This leaves people much weaker and with less muscle with which to burn calories. This means losing weight in future will be much harder.

NHS leaders know this and are grappling with how to fund the essential support people taking these weight loss jabs will need. It is far from certain whether remote monitoring and the occasional video call via an app - currently being trialled - will be enough to help people make the necessary lifestyle changes.

And then there is the problem, as with all new medications, that we simply do not know the long term consequences of mimicking our hormones which regulate hunger. Many experts who are in favour of GLP-1 argue that the dangerously obese patients who need these drugs will not live long enough to find out if they don’t take them.

For Mounjaro public data is only available up to May this year however between January and May 2024 there were 208 reports of it on the NHS yellow card scheme, including 31 serious reactions and one suspected death of a man in his sixties. The most popular GLP-1 agonist is semaglutide, known by the brand names Wegovy and Ozempic [although Ozempic is only prescribed on the NHS for diabetes, not obesity]. There have been 23 suspected UK deaths linked to semaglutide via the yellow card scheme since 2019.

There are risks of rare adverse reactions with any drugs. The greater risk with weight loss jabs is that people have to stop taking them and then end up fatter, weaker and live shorter lives as a result.