DR SAIRA BANO: Why I Expect to Move Many Patients Onto Reta Soon - The New Weight-Loss Drug May Help Those Stuck at the Mounjaro Plateau

It is easy to forget how fast the weight-loss landscape has changed. Not long ago, doctors had little more to offer people with obesity than standard advice on diet and exercise, even though for many patients that brought only limited long-term results.

Then the injectable medicines arrived — Ozempic, Wegovy and Mounjaro — and the field was transformed.

For the first time, patients could achieve substantial weight loss and, just as importantly, keep it off while continuing treatment.

Progress has not stopped there. More recently, the first of a new generation of weight-loss tablets has begun to appear, offering an option for people who do not like injections.

It is a world that would have seemed unimaginable only a few years ago.

For decades, obesity was exceptionally hard to treat, and even the most disciplined patients often regained the weight they had lost.

Now we have medicines — known collectively as GLP-1s — that can change that picture.

The next major advance may already be on the horizon: retatrutide.

The experimental drug is still in clinical trials, but its potency has already earned it the nickname the “Godzilla” of weight-loss injections. Early research suggests it could help some patients lose close to a third of their body weight.

It is not yet available in the UK, but demand has become so intense that thousands of Britons are reportedly turning to black-market versions, sometimes with serious consequences.

That has given the drug a reputation before it has even reached the market, and it is understandable that some doctors are wary when patients mention using an illegal medicine.

Even so, I believe retatrutide — often shortened online to Reta — could transform the lives of many people, especially those who have had little response to Wegovy or Mounjaro, or who have found their weight loss has simply stopped. This is what is often described as the “GLP-1 plateau”.

I work as a GP in both the NHS and private practice, specialising in obesity, and I have prescribed weight-loss injections for three years. In that time I have treated around 20,000 patients, so I have seen first-hand what helps and what does not. Many patients are already asking me about Reta.

Most are women aged between 35 and 60 who have been on the highest Mounjaro dose, 15mg, for a year or more. They have lost a significant amount of weight, but the numbers on the scales have stalled — and many remain obese.

Others have lost only a stone when they hoped to lose two. For some, the medicines have barely worked at all. That can be deeply upsetting, particularly for women in perimenopause or menopause, when hormonal shifts can make weight control harder. These are the patients I think could benefit most from retatrutide.

That does not mean it is suitable for everyone, and there are several important points to understand.

The drug is different because of the way it works. Wegovy copies a gut hormone called GLP-1, which reduces appetite. Mounjaro acts on GLP-1 and a second hormone, GIP, producing an even stronger effect. Retatrutide adds a third hormone, glucagon, which may both increase energy expenditure and reduce food intake.

The findings so far have been striking. In a trial published in May involving more than 2,300 adults, those on the highest dose lost about 28 per cent of their body weight over 80 weeks — roughly five stone for someone who started at 18 stone.

By comparison, people taking Wegovy typically lose about 15 per cent of body weight, while those on Mounjaro lose around 20 per cent.

It is an extraordinary development. The key question for many of my patients is whether retatrutide can overcome the weight-loss plateau.

There is reason to think it might.

As weight falls, the body adapts by burning fewer calories, which makes further loss more difficult. Retatrutide’s effect on glucagon may help offset that response.

Just as importantly, trial participants on retatrutide showed little evidence of their weight loss slowing down, even after 80 weeks.

For people who have already reached that plateau, the drug cannot come soon enough. Many have spent years battling their weight and believed these injections would finally provide the answer. They have watched celebrities and social media influencers undergo dramatic transformations and spent large sums on treatment, only to find that their own results are far more modest.

These are the patients I would most likely consider for retatrutide once it is approved, along with those who still have a very large amount of weight to lose.

One of my patients has lost six stone. That has transformed her life. But she is still obese, and her risk of heart disease and certain cancers remains elevated. Understandably, she wonders why others have lost so much more. For someone like her, retatrutide could make a major difference.

However, there are reasons to be cautious. In the trial, a quarter of people on the highest dose vomited, more than four in ten felt nauseous, and one in nine stopped treatment because of side effects.

I already see patients vomiting on the current injections. So if you only want to lose a few pounds, this is not the drug for you.

I would also strongly advise everyone to stay away from the black market. Retatrutide is not approved anywhere in the world, and factories in Britain making counterfeit injection pens have already been raided.

Some NHS patients have told me they are taking retatrutide, but in one case the patient was actually injecting insulin, a diabetes medicine.

I expect retatrutide to become available towards the end of next year. When it does, patients will begin on a low dose and gradually increase it, in the same way we introduce Mounjaro and Wegovy.

The same advice will apply too: these medicines are not a miracle cure. You still need to eat well and exercise regularly to preserve muscle and keep the weight off.

Without those changes, even the most effective weight-loss drug will do little in the long run.

Medication can reduce hunger, but lasting success depends on the habits you build alongside it.

When retatrutide finally arrives, I know I will be prescribing it to many of my patients — and I expect the results to be remarkable.