The wildly popular weight loss drug Ozempic could be made for less than $5 a month even though Danish pharmaceutical company Novo Nordisk charges about $1,000 for the shot in the United States, according to a study.

The study, published in the JAMA Network Open on Wednesday, found that a month's supply of the drug could be profitably manufactured for an estimated 89 cents to $4.73.

Novo Nordisk charges about $935.77 for a month's supply, but the company's website says the price can be lower depending on discounts and rebates.

The study from researchers at Yale University, King's College Hospital in London and Doctors Without Borders concluded that GLP-1s present in drugs like Ozempic and Wegovy "can likely be manufactured for prices far below current prices, enabling wider access."

"The profit margin is immense," Melissa Barber, a public health economist at Yale and one of the study's authors, told Fortune. "There should be a conversation in policy about what is a fair price."

Ozempic, which was approved by the FDA in 2017 for adults with type 2 diabetes, has become a sensation in helping people lose weight because of its active ingredient, semaglutide.

While Ozempic is not approved for weight loss, Novo Nordisk's Wegovy, which also contains semaglutide, is, according to University of California Davis Health.

Novo Nordisk's sales of Ozempic and Wegovy last year exceeded $18 billion, Fortune reported.

Sen. Bernie Sanders seized on the report to call on the drug maker to lower the price of Ozempic and Wegovy, saying the "outrageously high price has the potential to bankrupt Medicare, the American people and our entire healthcare system."

"A prescription drug is not safe or effective for a patient who cannot afford it," said Sanders, the chairman of the Senate Health, Education, Labor and Pensions Committee.

The company, in a statement to CNBC, said it had spent nearly $5 billion on research and development last year and will spend more than $6 billion to meet demand for GLP-1s.

Novo Nordisk also said that 75% of its gross earnings go to rebates and discounts to ensure patients have access to its drugs.