Quick Summary
- LLY shares declined approximately 2% following the release of weekly GLP-1 prescription figures
- Foundayo registered 3,707 prescriptions during week two, increasing from 1,390 in the initial week
- Oral Wegovy from Novo Nordisk achieved 18,410 prescriptions during its comparable second week
- Total prescriptions for Mounjaro, Zepbound, and Foundayo decreased 0.3% from the previous week
- Eli Lilly continues holding approximately 59% of weekly new prescription market share in GLP-1s
Eli Lilly experienced a roughly 2% stock decline on Thursday following the release of prescription data for its GLP-1 medication lineup — with Foundayo’s performance drawing particular investor scrutiny.
The pharmaceutical giant’s new oral weight loss medication, Foundayo, generated 3,707 total prescriptions during its second week of market availability. While this represents growth from the 1,390 prescriptions recorded in week one, the figure falls considerably short of Novo Nordisk’s oral Wegovy benchmark of 18,410 prescriptions during its corresponding second week in January.
RBC Capital Markets analyst Trung Huynh offered frank commentary on the situation. “While we believe comparisons early into launch should be considered immaterial, Foundayo’s uptake this week is likely to be received negatively,” he stated.
J.P. Morgan’s Chris Schott acknowledged the slower trajectory compared to Wegovy, though he characterized this outcome as expected. Wegovy entered the market with established momentum and stronger brand awareness before Lilly’s competing pill became available.
Foundayo received regulatory approval on April 1, 2026. Prescriptions became available through LillyDirect almost right away, with shipments commencing April 6. Wider distribution through retail pharmacies and telehealth platforms launched on April 9.
Eli Lilly has cautioned investors against drawing definitive conclusions from initial weekly data. Company representatives have emphasized that early figures may miss certain pharmacy partners and should be “best interpreted over time rather than as a complete count.”
Injectable Portfolio Demonstrates Stability
Lilly’s injectable medications showed more consistent performance. Mounjaro reached 758,400 total prescriptions for the week ending April 17, advancing from 749,500 in the preceding week. New Mounjaro prescriptions totaled 367,900, compared to 361,700 previously.
Zepbound experienced modest softness. Total prescriptions declined to 615,300 from 632,500, while new prescriptions rose slightly to 350,600 from 346,400.
Across all three products, Lilly’s Mounjaro, Zepbound, and Foundayo combination reached 1,377,400 prescriptions — representing a 0.3% decrease from the previous week’s 1,381,000.
Company Retains 59% Market Position
Despite the weekly decline, Eli Lilly preserved its position within the broader GLP-1 marketplace. The pharmaceutical company maintained approximately 59% of weekly new prescription market share, matching the prior week’s percentage.
The GLP-1 category overall sustained its expansion, advancing roughly 32% on a year-over-year basis.
Morgan Stanley analysts expressed greater confidence regarding the injectable portfolio. “We see ~6% upside to ’26 M+Z ests,” the firm noted, referencing 2026 projections for Mounjaro and Zepbound.
Morgan Stanley continues monitoring both medications as critical product cycles for Lilly, with particular attention to their influence on overall category expansion and competitive positioning moving forward.
While Eli Lilly shares fell approximately 2%, Novo Nordisk’s U.S.-traded stock climbed roughly 2% on identical prescription data — a divergent market reaction that highlights how investors interpreted the Foundayo versus Wegovy comparison.
Lilly’s injectable medications continue representing the foundation of its GLP-1 business, with Mounjaro and Zepbound data demonstrating consistent week-over-week advancement through April 17.
