The duopoly dominating the multi-billion-dollar GLP-1 weight-loss market has moved from pharmacy shelves to the federal courtroom. Novo Nordisk A/S (NYSE:NVO) filed a lawsuit in U.S. District Court in New Jersey against Eli Lilly and Company (NYSE:LLY) on July 21, accusing its primary rival of false advertising and unfair competition regarding television and digital campaigns for Zepbound and Mounjaro. While both pharmaceutical giants continue to deliver massive top-line growth, a look at their underlying fundamentals shows that one company is clearly pulling ahead in execution, clinical trials, and market expansion.

The Lawsuit: Misleading Ads vs. Scientific Evidence

Novo Nordisk A/S (NYSE:NVO)’s legal action centers on commercial advertisements aired during major broadcasts and social media platforms. Novo Nordisk claims that Eli Lilly’s promotional campaigns intentionally use outdated trial data to pit the highest approved doses of Lilly’s tirzepatide (Zepbound/Mounjaro) against lower, older doses of Novo’s semaglutide (Wegovy/Ozempic). Novo argues these ads create consumer confusion by omitting Novo’s recently approved higher-dose versions, demanding a permanent injunction to pull the ads and force Lilly to launch a corrective campaign.

Eli Lilly and Company (NYSE:LLY) fired back immediately, stating that its commercials are “truthful,” “transparent,” and grounded in direct scientific evidence. A spokesperson for Eli Lilly emphasized that the claims stem from the SURMOUNT-5 trial, which is a rigorous head-to-head clinical study directly comparing tirzepatide against semaglutide. Lilly asserted that rather than competing on product merits, Novo Nordisk is attempting to censor published trial results. Lilly confirmed it plans to defend itself “vigorously” in court.

Q1 2026 Financial Comparison: Lilly Takes the Lead

Both companies remain highly profitable, but Eli Lilly is currently demonstrating significantly faster top-line growth and stronger forward momentum based on their Q1 2026 financial results.

Eli Lilly and Company (NYSE:LLY)

Eli Lilly delivered exceptional growth in its Q1 2026 results, with revenue increasing 56% year-over-year to $19.8 billion. The growth was primarily driven by a 65% increase in sales volume, led by strong demand for its blockbuster GLP-1 medicines, Mounjaro and Zepbound.

The company also reported a significant improvement in profitability, with net income reaching $7.4 billion, or $8.26 per share, compared with $2.8 billion, or $3.06 per share, in Q1 2025. Non-GAAP EPS surged 156% to $8.55, reflecting strong operating leverage and robust commercial execution.

Supported by accelerating demand, Eli Lilly raised its full-year 2026 revenue guidance by $2 billion, increasing its expected revenue range to $82.0 billion–$85.0 billion. The company also lifted its non-GAAP EPS outlook to $35.50–$37.00, signaling continued confidence in its growth trajectory.

Novo Nordisk A/S (NYSE:NVO)

Novo Nordisk delivered solid headline growth in Q1 2026, but its results reflected a more complex operating environment. Net sales increased 32% year-over-year in constant exchange rates (CER) to DKK 96.82 billion ($13.8 billion). However, this growth was significantly impacted by a $4.2 billion non-recurring provision reversal related to the U.S. 340B Drug Pricing Program. Excluding this one-time benefit, adjusted sales declined 4% at CER due to lower realized prices in the U.S., despite continued volume growth in GLP-1 products.

Reported operating profit increased 65% in constant exchange rates to DKK 59.62 billion, although adjusted operating profit declined 6% at CER to DKK 32.86 billion, highlighting ongoing pricing and margin pressures.

Commercially, Novo Nordisk continued to advance its obesity franchise with the successful U.S. launch of the Wegovy oral pill, which generated DKK 2.26 billion in Q1 revenue. The company also received FDA approval for Wegovy HD (7.2 mg injection), which demonstrated nearly 21% mean weight loss in clinical trials, strengthening its long-term competitive position in the obesity treatment market.

Comparison: Which Company Is Doing Better?

Comparing the two companies, Eli Lilly is currently demonstrating stronger overall performance and momentum.

Eli Lilly’s dual GIP/GLP-1 mechanism, tirzepatide, has consistently shown higher weight-loss outcomes in clinical data compared with standard semaglutide-based treatments. This clinical advantage is translating directly into financial performance, with the company delivering 56% organic revenue growth in Q1 2026 and increasing its full-year revenue guidance by $2 billion.

Novo Nordisk, while continuing to expand its obesity treatment portfolio through the launch of oral Wegovy and the approval of Wegovy HD, has faced greater pricing pressures in the U.S. market. After excluding the impact of the non-recurring 340B accounting adjustment, the company’s underlying quarterly performance showed a 4% decline in adjusted revenue and a 6% decline in adjusted operating profit at constant exchange rates.

Insider Monkey Hedge Fund Data Analysis

Institutional data from Insider Monkey shows institutional positioning diverging between the two rivals. Eli Lilly maintained strong top-tier hedge fund backing, with 132 hedge funds holding shares in Q1 2026 compared to 137 funds in Q4 2025. Among the prominent holders, HealthInvest Partners AB (managed by Anders Hallberg and Carl Bennet) holds 29,821 shares valued at $35.77 million (representing 9.62% of their portfolio despite a 25% trim), while Bourgeon Capital (managed by John Zaro) increased its position by 5% to 24,426 shares valued at $29.30 million (4.31% of portfolio).

Novo Nordisk displays a significantly smaller hedge fund footprint, with holding concentration staying flat at 55 hedge funds in both Q1 2026 and Q4 2025. Notable institutional positions include Taproot Management (led by David Lin and Jason Beverage).

Conclusion

The legal feud between Novo Nordisk A/S (NYSE:NVO) and Eli Lilly and Company (NYSE:LLY) reflects how high the stakes are in the metabolic market. While Novo Nordisk continues to produce stellar profits and dominant global volume, Eli Lilly is currently winning the momentum battle thanks to higher efficacy data, faster U.S. commercial traction, and higher hedge fund conviction. As supply bottlenecks ease for both players, future outperformance will depend less on legal squabbles over advertising disclaimers and more on who can deliver next-generation oral formulations to patients first.

READ NEXT: 33 Stocks That Should Double in 3 Years and 15 Stocks That Will Make You Rich in 10 Years 

Disclosure: None. Follow Insider Monkey on Google News.