Forget Weight Loss Drugs: Here's An Even Better Reason to Invest in Eli Lilly

Eli Lilly (NYSE: LLY) is currently the leader in the weight loss market. Sales of the company's anti-obesity medicine, Zepbound, are growing fast. It also recently launched Foundayo, an oral GLP-1 drug that should help expand its addressable market. And Eli Lilly has several other highly promising candidates in this field. The projected rapid growth of the weight-loss drug market is a strong reason to consider the stock.

However, investors should keep in mind that other, newer anti-obesity therapies will enter the market. Even if they aren't as good as Eli Lilly's, they will at least disrupt the company's pricing power. Thankfully, Eli Lilly is well equipped to deal with these challenges over the medium term, partly thanks to an underappreciated (in my view) aspect of its business. Here's why Eli Lilly is a buy beyond its current growth pillars.

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Eli Lilly isn't a one-trick pony

Eli Lilly's tirzepatide, the compound marketed as Zepbound and also approved for Type 2 diabetes (where it is sold under the brand name Mounjaro), is setting industry records. It is already one of the best-selling compounds in the world, despite being approved for the first time not that long ago -- in 2022, to be exact. That highlights the strong demand for medicines in this niche, as well as the company's breakthroughs -- tirzepatide was the first dual GLP-1/GIP agonist approved by regulatory authorities. It's only natural that Eli Lilly should focus much of its efforts in this area.

However, the company has other products in its portfolio that, for many other pharmaceutical companies, would be key growth drivers. Consider the company's cancer treatment, Verzenio. Last year, this medicine generated $5.7 billion in sales, representing an 8% year-over-year increase. Taltz, an immunosuppressant, racked up $3.6 billion in sales, 9% higher than the previous fiscal year. Eli Lilly has other, newer products that analysts expect will eventually generate over $1 billion in annual sales. The list includes Ebglyss, an eczema treatment, Jaypirca, a cancer medicine, and Kisunla, a treatment for Alzheimer's disease.

These medicines span three therapeutic areas: Oncology, immunology, and neuroscience. Eli Lilly's ability to develop blockbuster drugs across multiple fields can help mitigate the impact of competition in its core therapeutic areas.

It's important to note that this is exactly what the company's biggest rival, Novo Nordisk, failed at. The Denmark-based pharmaceutical giant once dominated the weight-loss market. But once it lost ground to Eli Lilly, Novo Nordisk's financial results worsened, and its shares fell off a cliff. That's partly because Novo Nordisk generates almost all its revenue from its diabetes or weight-loss products while being far less diversified than Eli Lilly.

Eli Lilly is still diversifying

Eli Lilly has doubled down on its diversification plans in recent years, notably by acquiring smaller biotechs or signing licensing deals. Most recently, the drugmaker announced it would acquire Kelonia Therapeutics, a privately held company, for $3.25 billion in cash, along with potential milestone payments, for a total equity value of up to $7 billion. This acquisition grants Eli Lilly access to Kelonia Therapeutics' innovative gene therapy platform, which has the potential to improve the treatment of some cancers.

This deal also strengthens Eli Lilly's genetic medicine platform, which it has improved in recent years through other acquisitions, including that of Verve Therapeutics in 2025. Meanwhile, the company is expanding its neuroscience pipeline through the acquisition of Centessa Pharmaceuticals -- a drugmaker focused on developing drugs for sleep-wake disorders -- and deepened its oncology pipeline through the buyout of Scorpion Therapeutics.

This list is not exhaustive. What does all of this tell us about Eli Lilly? The company is not only positioned to make more breakthroughs and dominate the weight-loss market even as new drugs start competing with its medicines, but it is also looking to make significant breakthroughs in other fields and drive top-line growth well after its current crop of therapies has lost patent exclusivity. Those are strong reasons to consider the stock.

Prosper Junior Bakiny has positions in Eli Lilly and Novo Nordisk. The Motley Fool has positions in and recommends Centessa Pharmaceuticals Plc. The Motley Fool recommends Novo Nordisk. The Motley Fool has a disclosure policy.