Ozempic Maker Novo Nordisk Seeks Injunction Against Eli Lilly in Dispute Over Weight-Loss Ads -- 2nd Update

By Adam Whittaker

Novo Nordisk said it is asking a U.S. court to preliminarily halt rival Eli Lilly from advertising weight-loss drugs, days after accusing the Indianapolis drugmaker of using deceptive ads to mislead consumers in a lawsuit.

Friday's preliminary injunction request escalates legal proceedings initiated earlier this week by Novo Nordisk that accuse Eli Lilly of using outdated studies to promote its branded GLP-1 drugs, Mounjaro and Zepbound. Novo Nordisk said the motion, to be filed on Aug. 17 in New Jersey, would ask the court to stop Eli Lilly from advertising the drugs while the lawsuit proceeds.

Eli Lilly on Friday defended its advertising, saying head-to-head clinical trials are the strongest evidence for comparing medicines. "We stand behind the science and our advertising, and we will oppose this motion vigorously," a company spokesperson said.

Novo Nordisk, through its drugs Ozempic and Wegovy, and Eli Lilly are competing to control the nearly $80 billion weight-loss drug market. How much weight a drug helps patients lose is a key determinant of market success, and studies comparing the weight-loss effects of one drug compared with a rival one are hotly watched.

On Tuesday, Novo Nordisk accused Eli Lilly of using outdated studies to promote Mounjaro--aimed at diabetes sufferers--and Zepbound as helping consumers lose significantly more weight on average than the Danish company's own drugs. It said Eli Lilly's studies compare the highest injectable doses of the U.S. drugmaker's medicines against lower doses of Novo Nordisk's injectable medicines for obesity and type-2 diabetes.

Novo Nordisk said Friday that since it filed the lawsuit, Lilly hasn't removed the advertisements, which it described as "confusing and deceiving."

Novo Nordisk has now received approval for a higher dose of its injectable Wegovy drug. This means that Eli Lilly's campaign, which relies on data comparing 10/15 mg of Zepbound vs 1.7/2.4 mg of Wegovy, is out of date, Novo Nordisk said.

"This ad is especially misleading because there is no head-to-head clinical trial comparing the highest doses of these two medicines," Novo Nordisk said.

Lilly said Novo Nordisk hasn't tested its highest doses of semaglutide against the U.S. company's weight-loss medicines in any clinical trials. "Instead, it is using a lawsuit to advance comparisons it has never put to the test," it said.

Write to Adam Whittaker at adam.whittaker@wsj.com

(END) Dow Jones Newswires

July 24, 2026 08:31 ET (12:31 GMT)