3 Things Investors Need to Know Ahead of Eli Lilly's Q3 Earnings Report

Eli Lilly's stock saw substantial gains, primarily fueled by the exceptional performance of its tirzepatide franchise (Mounjaro/Zepbound), which more than tripled sales to $16.47 billion last year and drove total revenue up 32%. Despite tirzepatide sales growing 121% year-over-year in the first half of 2025, the stock recently declined 10.7% amid investor concerns. The company faces significant challenges, including declining sales from older drugs like Trulicity, a high valuation at 35.8 times forward earnings, potential loss of market exclusivity for Trulicity by 2027, and a revised lower outlook for the global anti-obesity drug market, all of which could impede its ability to sustain rapid growth.

Analysis

Eli Lilly's stock experienced a significant surge of 147.5% from late 2022 to mid-2024, primarily driven by its tirzepatide franchise (Mounjaro/Zepbound), which saw sales more than triple to $16.47 billion in 2024 and contributed to a 32% increase in total revenue. Despite a 121% year-over-year growth in tirzepatide sales during the first half of 2025, the stock has recently declined by 10.7% since June 2024, reflecting investor concerns ahead of its Q3 earnings announcement.

While tirzepatide's success has propelled growth, offsetting declining sales from older drugs like Trulicity and Jardiance, the company's Q2 revenue still climbed an outstanding 38% year-over-year. However, the sustainability of this rapid growth is questioned, especially given Goldman Sachs' reduced 2030 global anti-obesity drug sales estimate from $130 billion to $95 billion. Furthermore, tirzepatide's tolerability issues, causing some patients to opt for competitors like Novo Nordisk's Wegovy, present a competitive challenge.

The company trades at a rich 35.8 times forward-looking earnings, demanding continued exceptional growth to justify its valuation. Significant risks include the potential loss of Trulicity's U.S. market exclusivity by 2027, which could pressure Mounjaro sales through biosimilar competition, and the overall maturation of the GLP-1 market, making past rapid growth rates difficult to replicate. Investors face considerable risk if tirzepatide sales falter or growth normalizes to industry averages.

Key Decisions for Investors

• Investors should closely monitor Eli Lilly's Q3 earnings for tirzepatide sales performance and management's updated outlook on the anti-obesity market.
• Evaluate the sustainability of the company's high growth rate against its premium 35.8x forward earnings multiple, considering the revised market size estimates and competitive landscape.
• Assess the long-term impact of potential patent expirations for Trulicity and the broader GLP-1 market maturation on future revenue streams.