Eli Lilly’s Two-Front Victory: A Trillion-Dollar Valuation and a Pharmacy Benefit Win Reshape the Obesity Landscape

Eli Lilly has barrelled past a historic threshold, becoming the first pharmaceutical company to reach a market capitalisation of $1 trillion. The milestone, punctuated by a 1.9% share price advance to roughly $1,085, was quickly followed by another coup: CVS Caremark is reopening its commercial formularies to the company’s blockbuster weight-loss drugs, reversing a year-old snub that had tilted the playing field toward Novo Nordisk.

The pharmacy benefit manager will add Zepbound (tirzepatide) as an “additional preferred option” from October 2026. The move comes after CVS had dropped the drug from most lists last year, citing a more favourable deal with Novo’s Wegovy. Now Eli Lilly is back in the fold, and the impact looks substantial. CVS estimates that 25 to 30 million Americans are affected by the change, and the company projects savings of 10% to 15% in its obesity-spend category. Patients with commercial insurance could pay as little as $25 a month, depending on their plan, while Medicare Part D recipients can expect copays of around $50 from July 2026.

A Triple-Agonist That Mimics Surgery

Of even greater long-term significance is the data emerging from Lilly’s pipeline. The Phase 3 TRIUMPH-1 trial of retatrutide—a triple agonist targeting GLP-1, GIP and glucagon receptors—delivered weight loss that rivals bariatric surgery. Participants on the highest 12 mg dose shed an average of 28.3% of their body weight over 80 weeks, and more than 45% lost at least 30%. That compares with the 15% to 22% range typical of current GLP-1 therapies.

The potency, however, comes with side effects: 42% of the high-dose group experienced nausea, 33% diarrhoea and 25% vomiting. The dropout rate hit 11%, against 4.1% in the lowest dose cohort. Still, analysts see the risk-reward profile as compelling enough to maintain a consensus “Strong Buy” rating, with price targets clustering between $1,227 and $1,240. Eli Lilly plans to file for regulatory approval of retatrutide later this year, though a commercial launch remains several years away.

Near-Term Dependables: Mounjaro and Zepbound

The immediate growth engine remains the tirzepatide franchise. In the first quarter, Eli Lilly generated $19.8 billion in revenue, an increase of 55.5% from the prior year. The combined quarterly sales of Mounjaro (for diabetes) and Zepbound (for obesity) surpassed $12 billion. The company now commands roughly 60% of the US obesity-drug market, even as Novo Nordisk keeps up the pressure.

Should investors sell immediately? Or is it worth buying Eli Lilly?

The strong cash flow is funding an aggressive expansion beyond metabolism. Eli Lilly is spending up to $3.83 billion to acquire three vaccine developers: Curevo, LimmaTech Biologics and The Vaccine Company. Curevo brings a shingles candidate called Amezosvatein, which in Phase 2 testing generated an immune response comparable to established vaccines while triggering roughly half the rate of moderate-to-severe side effects. LimmaTech is targeting antibiotic-resistant pathogens, and The Vaccine Company focuses on the Epstein-Barr virus. The new infectious-disease unit will be led by Dr. Peter Marks, the former head of the FDA’s vaccine division.

Meanwhile, Eli Lilly is pumping another $4.5 billion into two manufacturing sites in Indiana, bringing its total investment in the state since 2020 to more than $21 billion. This is a direct response to surging demand for Zepbound and the next-generation oral therapy, Foundayo.

Foundayo: The Pill That Changes the Game

Foundayo (orforglipron) is the first approved oral GLP-1 therapy, a once-daily pill that requires no food or drink restrictions. In the ATTAIN-1 registration trial, patients on the highest dose lost an average of 12.4% of their body weight over 72 weeks, with similar results in those over 65. Starting this June, a block on market access for Foundayo is being lifted, meaning many commercially insured patients will now face only a $25 monthly copay. The drug also stands to gain Medicare Part D coverage from July 2026.

The combination of Foundayo’s convenience and the improved formulary access at CVS could rapidly expand Eli Lilly’s addressable patient pool. Management now expects full-year 2026 revenue to land between $82 billion and $85 billion. With the global obesity drug market forecast to more than double to $200 billion by 2030, Lilly’s manufacturing blitz and pipeline depth suggest the company is building for a long run at the top.