• The U.S. Senate will investigate the price of Novo Nordisk's popular weight loss and diabetes drugs Ozempic and Wegovy.
• Sen. Bernie Sanders asked Novo Nordisk's CEO in a letter how the price of the drugs is determined and about the amount the pharmaceutical company spends on research and development.
• Before insurance, Novo Nordisk charges about $1,000 per month for Ozempic and roughly $1,350 a month for Wegovy. A study last month said that Ozempic could be manufactured for less than $5 a month.

The U.S. Senate has launched an investigation into the high price of Novo Nordisk's popular weight loss and diabetes drugs Ozempic and Wegovy in the United States.

The investigation into the Danish drugmaker was announced by Sen. Bernie Sanders, the Vermont Independent who chairs the Health, Education, Labor and Pensions (HELP) Committee.

"The scientists at Novo Nordisk deserve great credit for developing these drugs that have the potential to be a game changer for millions of Americans struggling with type 2 diabetes and obesity," Sanders said in a Wednesday letter to CEO Lars Fruergaard Jørgensen.

"As important as these drugs are, they will not do any good for the millions of patients who cannot afford them," wrote Sanders.

Sanders also laid out in stark terms the dilemma facing American insurers, including the government, given how high the costs are for the potentially life-changing drugs. "If the prices for these products are not substantially reduced they also have the potential to bankrupt Medicare, Medicaid, and our entire health care system," he wrote.

Sanders noted that Novo Nordisk charges far less for the same drugs in other countries. The company "charges $969 in the United States for one month of Ozempic but just $155 in Canada and just $59 in Germany."

Wegovy, which is even more expensive than Ozempic, is subject to similarly disparate pricing overseas, wrote Sanders. A study last month said that Ozempic could be manufactured for less than $5 a month.

The powerful progressive senator also made a simple request of the drug company CEO: "Will Novo Nordisk substantially reduce both the list price and the net price of both Ozempic and Wegovy?"

Sanders asked Jørgensen in his letter how the price of the drugs is determined and to make clear the amount the pharmaceutical company spends on research and development. He gave Novo Nordisk until May 8 to answer a series of questions about the drug's pricing.

Novo Nordisk declined to provide production costs to CNBC following the release of the study and noted that it spent $5 billion on research and development in 2023 and will spend more than $6 billion this year to boost manufacturing for GLP-1s.

In a statement to CNBC Wednesday in response to the letter, Novo Nordisk said the company agrees with Sanders that access to the drugs is important but highlighted the complexities of the healthcare industry.

"It's easy to oversimplify the science that goes into understanding disease and developing and producing new treatments, as well as the intricacies of U.S. and global healthcare systems. However, the public debate doesn't always take into account this extremely complex reality," the company said.