Danish pharmaceutical giant Novo Nordisk says about 13 million Australians are living with obesity or are overweight, potentially making half the population candidates for its weight-loss drugs Ozempic and Wegovy.

The federal government is reluctant to reimburse the so-called GLP-1 drugs for weight loss, but Novo Nordisk says many Australians would be willing to pay the out-of-pocket costs for its blockbuster medicines, which can be up to $460 a month.