Eli Lilly's Trajectory: Projecting 10 Years Ahead

Eli Lilly (NYSE: LLY) is currently performing exceptionally well, a fact recognized by Wall Street. The stock's price-to-earnings (P/E) ratio, while high at 50, is below its five-year average of 54. In comparison, the S&P 500 index has a P/E ratio of 28.5. Before investing in Lilly shares, it's crucial to consider potential developments over the next decade.

Drivers of Eli Lilly's Current Success

The primary driver behind Eli Lilly's success is the performance of its GLP-1 drugs, Mounjaro (for diabetes) and Zepbound (for weight loss), which currently dominate the market. This success has significantly impacted the company's financials, with Mounjaro's sales increasing by 109% year-over-year in the third quarter of 2025. Zepbound's performance was even more impressive, with a 185% increase in sales.

The substantial sales growth has understandably generated excitement among investors. Overall sales for the company increased by 54%, reflecting the strong demand for weight loss and related medications in the pharmaceutical industry. Health tracking apps like Shotlee can help monitor the effectiveness of such medications, providing valuable insights for users and healthcare providers.

However, this very success should also raise concerns for investors.

Competition and Market Dynamics

While Eli Lilly is experiencing success with its GLP-1 medications, Novo Nordisk was the first to introduce them to the market. Eli Lilly's medications have simply gained more popularity, allowing the company to overtake Novo Nordisk as the market leader in the weight loss sector. Potential investors in Eli Lilly stock should consider the risk of the company being dethroned.

This is a valid concern, as Pfizer (NYSE: PFE) is actively working to enter the GLP-1 market after an internal candidate failed. Pfizer has already acquired a company with a promising GLP-1 drug candidate and has established a distribution agreement with another company, hoping their GLP-1 candidate proves successful. Should either of these medications gain approval and demonstrate superior outcomes compared to Mounjaro and Zepbound, Eli Lilly could find itself in Novo Nordisk's former position. As the current industry leader, Eli Lilly faces competition from numerous companies vying for its position.

Patent Expiration and Long-Term Outlook

The 10-year timeframe is crucial because it approximates the remaining patent protection period for Mounjaro and Zepbound. The significant investment required to develop and market new drugs grants manufacturers exclusive selling rights. However, this patent protection is limited in duration. Upon expiration, generic drug manufacturers can produce and sell copies of the medication at lower prices. This typically results in a substantial decrease in revenue for the original product, a phenomenon known as a patent cliff.