DR SAIRA BANO: Why I’ll be switching many of my patients to Reta as soon as I can – the new weight-loss drug is the only hope for those unable to get over the ‘Mounjaro plateau’

It is easy to forget how quickly the world of weight loss has changed. Five years ago there was no such thing as a truly effective treatment for obesity. All that doctors could offer was advice on diet and exercise, knowing, for many patients, it would make little lasting difference.

Then came the weight-loss jabs – Ozempic, Wegovy and Mounjaro – which transformed the field.

Finally we had treatments that could help patients lose substantial amounts of weight and, crucially, keep it off for as long as they continued taking them.

And the breakthroughs kept coming. This year the first of a new generation of weight-loss pills began to emerge, promising to make treatment easier for patients who dislike injections.

It’s a world I could scarcely have imagined just a few years ago.

For decades, obesity had proved extraordinarily difficult to treat, with even the most determined patients often regaining the weight they had worked so hard to lose.

Now, for the first time, we have medicines – collectively known as GLP-1s – capable of changing that.

And the next revolution could be around the corner: retatrutide.

Still undergoing clinical trials, the experimental drug has already been dubbed the ‘Godzilla’ of weight-loss jabs due to its potency, with early research suggesting it could help patients shed close to a third of their body weight.

It isn’t available in the UK yet, but in a bizarre twist, demand is so strong that thousands of Britons are buying black-market versions – sometimes with disastrous consequences (more on that later).

That means the drug already has a reputation, and many people view it with suspicion – including doctors who hear that their patients are injecting an illegal medicine. I understand that.

But I believe retatrutide – or Reta, as it is called online – could change the lives of countless people, particularly those who have not responded to Wegovy or Mounjaro, or who have simply stopped losing weight on them. This is what we call the ‘GLP-1 plateau’.

I work as a GP both in the NHS and privately, specialising in obesity, and have prescribed weight-loss jabs for three years. In that time I’ve treated about 20,000 patients, so I know what works and what doesn’t. And many are already asking me about Reta.

Most are women aged 35 to 60 who have been taking the highest dose of Mounjaro, 15mg, for a year or more. They have lost a considerable amount of weight but the scales have stopped moving – and many are still obese.

Others have lost a stone when they hoped to lose two. For an unfortunate few, the drugs have barely worked at all. This can be deeply distressing, particularly for women going through the perimenopause or menopause, when hormonal changes can make weight management harder. It is these patients who I believe could benefit most from retatrutide.

That doesn’t mean it is for everyone, and there are important things you should know.

First, it’s worth understanding why this drug is different. Wegovy mimics a gut hormone called GLP-1, which reduces appetite. Mounjaro targets GLP-1 and a second hormone, GIP, with an even greater effect. Retatrutide adds a third: glucagon, which may increase the amount of energy the body burns, as well as reducing how much patients eat.

The results have been remarkable. In a trial published in May involving more than 2,300 adults, those taking the highest dose lost about 28 per cent of their body weight over 80 weeks – equivalent to roughly five stone for someone starting at 18 stone.

Those taking Wegovy typically lose 15 per cent of body weight, and those on Mounjaro 20 per cent.

It is a staggering advance. The big question for my patients is whether retatrutide can break the weight-loss plateau.

And there is good reason to think it might.

As people lose weight their bodies adapt by burning fewer calories, making further weight loss ever harder. Retatrutide’s action on glucagon may help counter this.

Crucially, in trials, those on retatrutide showed little sign of weight loss levelling off, even after 80 weeks.

For those who have already hit that plateau, the drug cannot come soon enough. Many have spent their lives struggling with their weight and believed these injections would finally be the answer. They’ve watched celebrities and social media influencers undergo transformations and spent thousands on treatment, only to find their own results fall far short.

These are the patients I would consider offering retatrutide when it is approved, and those with an especially big amount of weight to lose.

One of my patients has lost six stone. It has been life-changing. But she is still obese, with an elevated risk of heart disease and certain cancers. Naturally, she wonders why others have lost so much more. For someone like her, retatrutide could make a big difference.

But there are reasons to be cautious. In the trial, a quarter of those taking the highest dose experienced vomiting, while more than four in ten suffered nausea. One in nine on that dose gave up because of side effects.

I already see patients vomiting on current jabs. So if you only need to shift a few pounds, this is not for you.

I’d also urge everyone to avoid the black market. Retatrutide is not approved anywhere in the world, and factories in Britain churning out fake injection pens have already been raided.

I see many NHS patients who tell me they are taking retatrutide. One turned out to have been injecting the diabetes drug insulin.

I expect retatrutide to arrive towards the end of next year. When it does, patients will start on a low dose and slowly increase it – the same pathway we follow with Mounjaro and Wegovy.

And the same advice will apply. These drugs are not a magic wand. You must eat well and exercise regularly to protect muscle and keep the weight off.

Without these steps, you can try all the weight-loss drugs in the world and they won’t make much difference.

A drug can quieten your hunger, but it is the habits you build alongside it that determine whether the results last.

When retatrutide finally arrives, I know I will be giving it to many of my patients – and I expect to see some remarkable results.