It’s a tale of two drugmakers in the red-hot obesity drug market. 

Both Novo Nordisk and Eli Lilly are grappling with lower prices in the U.S., but their 2026 outlooks are diverging sharply: While Novo is bracing for a sales decline, Lilly sees revenue jumping again thanks to its blockbuster medicines. 

The split in guidance – despite similar headwinds – underscores the strength of Lilly’s position in the obesity and diabetes drug market, underpinned by its more effective injections and early foray into direct-to-consumer sales, among other factors. While Novo Nordisk effectively made the drugs mainstream, Lilly has since taken a clear edge in market share — and the forecasts show it will likely only extend its advantage this year.

“The difference in sales momentum and market share trend was visible throughout 2025, but the dichotomy between the two companies’ prospects was accentuated within this 24-hour period in which Novo guided below consensus and Lilly guided above consensus expectations,”  Leerink Partners analyst David Risinger told CNBC on Wednesday. 

“That really solidified an investor’s mind that Lilly is going to be the dominant player in obesity going forward,” he added. 

This year, all eyes will be on how Lilly’s upcoming obesity pill, orforglipron, fares against Novo’s own oral Wegovy drug, which has had an explosive U.S. launch this year.

In an interview on CNBC’s “Squawk Box” on Wednesday, Lilly CEO Dave Ricks said 20 million to 25 million patients are currently taking both companies’ medicines. But he said the total addressable market of patients in the obesity space is “gigantic.” 

Lilly similarly pointed to a “global pricing decline in the low- to mid- teens [percentages] this year.” That comes after the landmark “most favored nation” deals both companies struck with President Donald Trump in November to slash obesity and diabetes drug costs, along with their recent efforts to further reduce direct-to-consumer prices for their treatments. 

The agreements with Trump are expected to take a bite out of both companies’ sales, but eventually increase volumes of prescriptions for their drugs. Still, Lilly is bullish about other factors that will help offset that pricing pressure. 

That includes continued worldwide demand for its obesity drug Zepbound and diabetes counterpart Mounjaro and the expected launch of its GLP-1 pill for obesity in the second quarter, pending U.S. approval. Lilly also pointed to government Medicare coverage of obesity treatments starting for the first time by at least July, one of the winning features of the drug pricing deals with Trump. 

Lilly’s Ricks told CNBC that coverage will open up access to 40 million new Medicare beneficiaries, “and that could be quite expansive to volume.”

Overall, Risinger called Lilly’s guidance “very encouraging” and said the “price per volume trade-off is playing out well” for the company.

He said tirzepatide, the active ingredient in Zepbound and Mounjaro, is “superior” in its effectiveness and tolerability compared to semaglutide, the ingredient in Novo’s obesity and diabetes drugs. That was proven in a head-to-head clinical trial conducted by Lilly in 2024, and prescription trends show that the company’s drugs are preferred among prescribers.  

“I think that’s what is driving Lilly’s market share gain” relative to Novo, Risinger said. 

Another factor that sets Lilly and Novo apart is patent exclusivity. While Novo said expiring patents in some international markets pose a challenge, Lilly’s Ricks said tirzepatide should be protected into “the back half of the 2030s” in major markets. 

Risinger noted that Lilly is still working to drive global uptake for tirzepatide, which won U.S. approval for obesity in 2023.