Eli Lilly Shares Surge on Weight-Loss Drug Momentum. Is It Time to Buy the Stock?

The share price of Eli Lilly (NYSE: LLY) jumped last week after the drugmaker reported strong sales of its GLP-1 weight-loss drugs and issued upbeat 2026 guidance. The stock is now up more than 30% over the past year.

Let's take a closer look at Eli Lilly's latest results and prospects to see if the stock's momentum can continue.

Weight-loss drug sales surge

Lilly's GLP-1 drugs continue to be the company's biggest growth driver. In Q4, sales of Mounjaro surged 110% to $7.4 billion, while Zepbound revenue soared 123% from $1.9 billion a year ago to $4.3 billion. Its third-largest drug, Verzenio (treats breast cancer), saw sales rise 3% to $1.6 billion.

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Mounjaro and Zepbound have the same active ingredient, tirzepatide, but the Food and Drug Administration (FDA) has approved them for different use cases. Mounjaro is approved to help lower the blood glucose levels in adults with type 2 diabetes, while Zepbound is approved to treat weight loss in obese adults or overweight adults who have at least one related ailment, like high cholesterol. That said, both drugs are mostly prescribed off-label to help people lose weight.

Overall, Lilly grew its Q4 revenue by 43% to $19.29 billion, while adjusted earnings per share (EPS) jumped 42% to $7.54. The results cruised past analyst expectations, as compiled by LSEG, for adjusted EPS of $6.67 on sales of $17.96 billion.

Looking ahead, the company guided for 2026 revenue of between $80 billion and $83 billion, representing 25% growth at the midpoint. It forecasted adjusted EPS to range from $33.50 to $35. Its projections were well ahead of the consensus, which was looking for EPS of $33.23 on sales of $77.72 billion.

Lilly's robust outlook for 2026 stems from the expected strong continued demand for both Mounjaro and Zepbound, which could be bolstered by the drugs being covered by Medicare later this year. Meanwhile, the company expects its next big GLP-1 blockbuster drug, orforglipron, to be approved for obesity in Q2.

Given that orforglipron is a pill taken orally instead of by injection, Lilly has a big opportunity to greatly expand the already huge market for GLP-1 drugs, as many people don't like jabbing themselves with needles. Orforglipron also doesn't need specialized injection pens or cold storage and transport, so it should be able to be ramped up more quickly than earlier injectable drugs.

Is Lilly stock a buy?

Lilly is a dominant player in the GLP-1 weight-loss market, and the approval of orforglipron should be a big growth driver in the coming years. The drug will be introduced in the U.S. this year and a few other markets, and then rolled out more broadly to other international markets in 2027.

The stock currently trades at a forward price-to-earnings (P/E) ratio of 33 times 2026 analyst estimates, but that drops to below 27 times based on the 2027 consensus. Given the company's strong GLP-1 growth and its potential with orforglipron, I think the stock's momentum can continue and that it's not too late to buy the stock.

Geoffrey Seiler has no position in any of the stocks mentioned. The Motley Fool recommends London Stock Exchange Group Plc. The Motley Fool has a disclosure policy.