A weight- loss win? The jabs leading a revolution

Obesity was once medicine's Cinderella subject with some questioning whether the condition should even be viewed as a biological disorder. But the arrival of a new class of appetite-suppressing drugs such as Ozempic and Wegovy has transformed obesity treatment into the most scientifically exciting and commercially lucrative area of healthcare.

- By Hannah Devlin, Nicola Davis and Jane Clinton

These drugs lead to dramatic weight loss, are shifting perceptions and, according to a series of results announced at the European Congress on Obesity (ECO) in Málaga this month, promise health benefits that extend far beyond weight management.

“It’s been an extraordinary week,” said Prof Susan Jebb, a public health nutrition scientist at the University of Oxford, who has researched obesity treatments since the 1980s and presented the findings at the ECO meeting. “Obesity has been [in the background] for so long and it’s been such a slog. These drugs have energised the field and it has happened so fast.”

First developed to help lower blood sugar levels as a diabetes treatment, it was quickly apparent that Novo Nordisk’s drug semaglutide (the active ingredient in Ozempic and Wegovy jabs) has a dramatic effect on weight. The drug works by mimicking a hormone, GLP-1, which is released in the gut when we eat and acts on receptors around the body, including the brain.

Eli Lilly’s rival product, Mounjaro, contains the active ingredient tirzepatide. This emulates GLP-1 as well as a second hormone producing even more impressive results, according to the first head-to-head trial in which participants lost an average of 20% of their body weight after 72 weeks.

The benefits of being at a healthy weight are substantial, with one study suggesting weight-loss jabs could reduce the risk of 42 diseases including heart disease, cancer, clotting disorders, Alzheimer’s, chronic kidney disease, addiction and psychiatric conditions. There is evidence these benefits go beyond what might be expected due to the drugs’ metabolic effects.

“We know that almost every aspect of health is better if you’re a healthy weight,” said Jebb. “What we haven’t really nailed is whether those effects are independent of weight. There may be weight independent effects. My reading is that the jury is still out.”