The inside story of the race to develop Ozempic – the world's first truly effective and safe obesity drug – and its potentially revolutionary effects on public health, and our deeper culture and values.

Weight loss medications like Ozempic and Wegovy were born from a breakthrough in type 2 diabetes treatment, tricking users into feeling full. But these drugs are proving so transformative that entire industries are being disrupted. Fast food giants, supermarkets, dialysis kit makers and beer companies, all of which rely on a steady stream of obese customers, are feeling the squeeze. Ozempic's creator, the Danish company Novo Nordisk, has metamorphosed into a behemoth with a market capitalisation of almost half a trillion dollars. Countless celebrities, from Oprah Winfrey to Elon Musk sing Ozempic's praises.

The story of obesity drugs, however, goes far beyond billion dollar profits. Their invention is set to change the world in profound ways and crystallises difficult questions about inequality and morality. Off the Scale is not a parable of good versus evil, but a deeply human narrative that lays bare some of our deepest impulses and fears. There are heroes who work for one of the largest pharmaceutical companies in the world, and there are ordinary people who, in their quest to become thin, are taking vital drugs intended for people who are morbidly obese.

As the popularity of Ozempic continues to grow, one question looms in the minds of investors, healthcare workers and politicians: are these drugs too good to be true? Aimee Donnellan marshals the evidence to forecast the future of these drugs—and examines what their explosive popularity tells us about our ideals of beauty, the lengths to which people will go in order to become thin, the current state of healthcare, and the workings of the pharmaceutical industry.