‘Godzilla’ slimming shot is even better than Ozempic: study shows metabolism-boosting retatrutide helps users lose a quarter of their weight in less than a year

A new slimming shot can help people lose a quarter of their body weight, making it the most effective method yet.

Trials of the drug – dubbed the ‘Godzilla’ of appetite suppressants – have helped people lose an average of 24 percent of their body weight in less than a year.

Unlike other drugs, retatrutide not only suppresses appetite, but also speeds up metabolism.

This helped it outperform the Wegovy, Ozempic and Mounjaro jabs, which are currently sold in the millions around the world.

Research shows it helped obese people lose an average of 4.3kg in just 48 weeks.

The results were even starker in women, who lost 28.5 percent of their body weight, compared to 21.2 percent in men.

Presenting their findings at the European Obesity Congress in Venice, Dr Ania Jastreboff, director of the Yale Obesity Research Center, said: ‘The results are striking.

‘A phase two study did not see this degree of weight reduction in this time frame.’

Weight loss shots currently prescribed by the NHS and sold privately slow digestion and reduce appetite by mimicking hormones that regulate hunger and feelings of fullness.

They are designed to work like one of these hormones, known as glucagon-like peptide 1 (GLP-1).

The two best-selling drugs are called Wegovy or Ozempic and both contain the same main ingredient semaglutide, in different doses.

Originally designed to tackle type 2 diabetes, it was repurposed for obesity and studies found the stronger dosage form could help users lose 15 percent of their body weight in 68 weeks.

Mounjaro followed, who not only mimicked GLP-1 but also targeted a hormone called GIP to boost its effect on appetite suppression.

Studies have shown that it can help obese people lose 22.5 percent of their body weight in 72 weeks, at the highest dose of 15 mg.

Although approved, the phase 2 trials of retatrutide show that the impact on weight loss could be the largest yet.

The study of 338 obese people, published in the New England Journal of Medicine, found that participants lost 24 percent of their body weight over a 48-week period.

Experts believe that longer treatment with the drug can help users lose as much as 30 percent.

More obese participants lost an even greater percentage of their body weight: 26.5 percent in 48 weeks. Unusually, 100 percent of trial participants lost at least 5 percent.

In addition to GLP-1 and GIP hormones, retatrutide targets a third hormone known as glucagon, which prompts the body to burn more fat when we exercise.”

Professor Alex Miras, an obesity expert at the University of Ulster, said: ‘It’s basically Mounjaro, but turbocharged.

‘What glucagon does is it increases energy expenditure, so the amount of energy you burn.

‘So there are two mechanisms; reducing food intake and increasing energy expenditure. Until now, all medicines were only aimed at reducing food intake.’

Like all previous GLP-1 drugs, retatrutide has led to side effects such as nausea, diarrhea and constipation.

Larger trials are now underway with results in 2026, when it could be approved for use by the NHS.

Professor Naveed Sattar from the University of Glasgow, who has worked on trials of other weight loss jabs, said: ‘Five or 10 years ago we would never have imagined drugs that would cause this kind of weight loss.

‘The trial suggests that retatrutide is still not at its peak, so more weight loss is likely to occur.

‘If we give this drug any longer, I think it could reach almost 30 percent of a person’s body weight.

‘That’s a lot of damn weight. The question is whether this can be done safely and large trials are planned to test that.’

Nadia Ahmad, Ely Lilly’s Associate Vice President for Obesity, said: ‘We are very excited about the level of weight loss that retatrutide has achieved by activating three receptors, making it different from those currently on the market.’