A shake-up may be brewing in the market for GLP-1 diet drugs Friday, and it's making itself felt all across the field of companies selling (or hoping to sell) semaglutide and related drugs for treating diabetes and losing weight.

Stock prices for Novo Nordisk fell by about 3% at market open after the Biden administration selected its revolutionary drugs for mandatory price negotiations.

The US plans to slash the price it pays for the Novo Nordisk A/S blockbusters Ozempic and Wegovy, the latest drugs to be targeted under legislation that’s expected save the government more than $200 billion over a decade.