Is the Weight-Loss Drug Market Really a Winner-Take-All Fight Between Novo Nordisk (NVO) and Eli Lilly (LLY)?

On August 13, 2026, Novo Nordisk A/S (NYSE:NVO) CEO Mike Doustdar told Reuters that investors are underestimating how much the obesity drug market will fragment as new treatments arrive. He pushed back on the idea that Novo and Eli Lilly and Company (NYSE:LLY) are locked in a zero-sum battle for the same shrinking pool of patients.

Why This Matters

Novo’s market value has fallen sharply since its 2024 peak, while Lilly’s has climbed past $1 trillion. Wall Street has largely framed the rivalry as one company winning at the other’s expense.

That raises the real question: is Doustdar’s segmentation thesis a genuine read on where the obesity market is headed, or is it the kind of thing a CEO says when his stock is losing?

Is the Weight-Loss Drug Market Really a Winner-Take-All Fight Between Novo Nordisk A/S (NVO) and Eli Lilly and Company (LLY)?

The Bull and Bear Case: Novo Nordisk

Doustdar said the market will not be “Coke versus Pepsi. It will be Coke and Pepsi and Fanta and Dr Pepper and Red Bull,” arguing patients will sort themselves across many differentiated GLP-1 options rather than one winner taking the whole category. He said Novo Nordisk A/S (NYSE:NVO)’s oral Wegovy pill already holds 90% share of the oral GLP-1 market, partly because its data shows better weight loss than Eli Lilly and Company (NYSE:LLY)’s Foundayo pill. Lily’s CEO compared his ambitions for the obesity portfolio to Novo’s insulin business, where it sells half the world’s insulin across 12 different brands rather than one dominant product.

Novo’s next-generation obesity drug CagriSema helped patients lose an average of 23% of their body weight in trials, trailing the more than 25% seen with Lilly’s Zepbound. Doustdar acknowledged the drug “has been written off pretty much by all investors.” The obesity market Novo Nordisk A/S (NYSE:NVO) and Lilly are fighting over is expected to be worth more than $100 billion a year by 2030, according to analyst estimates, which means even small share shifts carry enormous financial stakes.

The Bull and Bear Case: Eli Lilly

Eli Lilly and Company (NYSE:LLY)’s Zepbound already outperforms Novo’s CagriSema on weight-loss data. The company’s market capitalization has continued climbing past $1 trillion, a sign investors currently favor Lilly’s execution over Novo’s broader segmentation argument.

However, Doustdar’s insulin-market comparison is a warning as much as a defense: If new rivals split up the obesity market as Novo’s diabetes business did, they might quickly shrink Eli Lilly’s lead and show that its stock price is too high.

Insider Monkey’s Hedge Fund Data

Eli Lilly and Company (NYSE:LLY) was held by 132 hedge funds as of Q1 2026, down from 137 the prior quarter. Novo Nordisk A/S (NYSE:NVO) held steady at 55 holders.

Conclusion

Doustdar is betting the obesity market ends up looking like the soda aisle rather than a two-horse race. But for now, Lilly’s stock price says the market isn’t buying that argument yet.

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Disclosure: None. This article is originally published at Insider Monkey.