Eli Lilly & Co. is asking people who took copies of its blockbuster weight loss drug to give the company access to their medical records as it continues to build a case against businesses selling the compounded drugs.

Novo Nordisk and Eli Lilly are offering discounts to encourage more insurance coverage of the medicines, which carry price tags of over $1,000 a month.

The letter is the latest sign that the battle between the brand-name drug manufacturers and the companies that make and sell the compounded versions has intensified.

U.S. pharmaceutical giant Eli Lilly named a new chief financial officer on Monday during a critical time for the company's exploding weight-loss drug market.

Roche presented early-stage data on its obesity injection and pill at EASD. Meanwhile, Oura enters into metabolic health market with acquisition of Veri.

As weight-loss treatments dominate the pharmaceutical market, Swiss drugmaker Novartis AG (SWX: NOVN) is choosing a different path. While competitors like Eli Lilly and Novo Nordisk race to capture the booming weight-loss drug market,

Swiss pharmaceutical giant Novartis said Wednesday that it does not plan to enter into the "frenzy" of weight loss drugs.

The weight-loss market is heating up as a number of companies are looking for a way to upend the dominance of market leaders Novo Nordisk and Eli Lilly by introducing GLP-1 pills.

As Eli Lilly and Novo Nordisk continue to dominate the lucrative weight-loss drug market, smaller competitors are gearing up to release their own treatments, aiming to challenge the two industry leaders.