Weight-loss jabs such as Wegovy could be made for just $3 a month, according to new analysis, potentially making the treatment available to millions in poorer countries as patents expire.

More than a billion people live with obesity worldwide, with rates rising fast in lower-income nations as they shift to westernised diets and more sedentary lifestyles.

The World Health Organization designated semaglutide – sold to treat obesity under the brand name Wegovy, and diabetes under the brand name Ozempic – as an essential medicine in September last year.

But global health leaders warned at the time that high prices were limiting access.

New research, published as a pre-print, suggests that semaglutide could be mass produced for $3 (about £2.35) for a monthly dose in its injectable form.