Novo Nordisk shares slipped after researchers boosted Eli Lilly’s weight loss drugs

Ozempic and Wegovy maker Novo Nordisk (NYSE:NVO) saw its shares drop nearly 2% on Monday, after a new study showed that Eli Lilly's (NYSE:LLY) weight loss treatments outperformed those made by its Danish rival.

The analysis, published in JAMA Internal Medicine, compared the weight loss effects of tirzepatide (Zepbound) and semaglutide (Wegovy) in 18,000 overweight and obese adults over a year.

The study found that adults taking tirzepatide lost more weight at three, six, and twelve months compared to those taking semaglutide.

Specifically, the study claimed tirzepatide users were 76% more likely to lose at least 5% of their body weight, 154% more likely to lose 10%, and 224% more likely to lose 15%.

Nevertheless, it was not a “head to head” controlled trial, rather researchers compared health data and ‘weight loss trajectories’ of patients taking the respective drugs, and, also adjusted the findings to account for individual risk factors.

Novo Nordisk, in comments published by Reuters, said a direct clinical trial would be necessary for a fair comparison.

Both Novo Nordisk and Eli Lilly are the key players in the fast growing weight-loss drug market, which analysts predict could reach $150 billion in annual sales by the early 2030s.

Both sets of weight loss drugs are experiencing ongoing supply shortages, due to high demand worldwide.