Cigna will cap how much insurance can spend on weight loss drugs as it tries to expand coverage

Cigna on Thursday said it will limit how much health plans and employers spend on weight loss drugs each year in a bid to expand insurance coverage for those highly popular treatments.

The move comes as many insurers mull whether they should cover those drugs or drop them from their plans altogether due to their high costs. Americans have flocked to the treatments, along with similar diabetes drugs, despite their hefty list prices of roughly $1,000 per month or up to $15,000 per year.

The effort by insurance giant Cigna could make weight loss treatments more accessible. Most insurance plans cover diabetes treatments.

Cigna's pharmacy benefits management unit will limit spending increases for weight loss and diabetes drugs to a maximum of 15% annually, a company spokesperson told CNBC. Currently, some health plans are seeing spending on the drugs rise 40% to 50% annually, according to the spokesperson. 

As part of that effort, Cigna's Evernorth unit struck agreements with drugmakers Novo Nordisk and Eli Lilly, the spokesperson said. Cigna did not provide further details on what those agreements look like.

A spokesperson for Eli Lilly on Thursday said employers should "prioritize solutions that facilitate access to comprehensive and patient-centered" obesity care, given how the condition affects people around the world.

A Novo Nordisk spokesperson on Thursday said the company works with all payers "as part of our commitment to expand patient access to anti-obesity medicines." They deferred CNBC to Cigna for details on the insurance spending cap.

The company called the effort the health-care industry's "first financial guarantee" for coverage of the drugs, which are also known as GLP-1s. Those medicines treat weight loss and