TLDR
- Shares of LLY declined approximately 2% following lackluster prescription trends for its newest GLP-1 product
- Foundayo’s second week saw 3,707 prescriptions, representing growth from week one’s 1,390
- Comparative data shows Novo Nordisk’s oral Wegovy achieved 18,410 second-week prescriptions
- Total prescriptions for Mounjaro, Zepbound, and Foundayo declined 0.3% on a weekly basis
- The company retains approximately 59% of new weekly prescriptions in the GLP-1 space
Shares of Eli Lilly retreated roughly 2% Thursday following the release of prescription data for its GLP-1 medication lineup — with Foundayo’s performance falling short of investor expectations.
The pharmaceutical giant’s newly launched oral weight management medication, Foundayo, registered 3,707 total prescriptions during its second week of availability. While this represents substantial growth from the initial week’s 1,390 prescriptions, it pales in comparison to the benchmark established by Novo Nordisk’s oral Wegovy, which captured 18,410 prescriptions during its comparable second week in January.
RBC Capital Markets analyst Trung Huynh offered a frank assessment of 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 analyst Chris Schott acknowledged the slower trajectory compared to Wegovy but suggested this outcome was predictable. He noted that Wegovy enjoyed both a first-mover advantage and established brand awareness when Lilly’s competing product entered the market.
Foundayo received regulatory approval on April 1, 2026. Prescriptions became available through LillyDirect nearly immediately, with initial shipments commencing April 6. Wider distribution through retail pharmacies and telehealth platforms began April 9.
The company has cautioned investors against drawing definitive conclusions from preliminary weekly data. Lilly has emphasized that early figures may not reflect all pharmacy distribution channels and should be “best interpreted over time rather than as a complete count.”
Injectable Products Show Resilience
The injectable segment of Lilly’s GLP-1 lineup demonstrated greater consistency. Mounjaro registered 758,400 total prescriptions during the week ending April 17, climbing from 749,500 the previous week. New Mounjaro prescriptions totaled 367,900, compared to 361,700 in the prior period.
Zepbound experienced modest weakness. Total prescriptions decreased to 615,300 from 632,500, although new prescriptions grew slightly to 350,600 from 346,400.
Across all three products — Mounjaro, Zepbound, and Foundayo — Lilly recorded 1,377,400 total prescriptions, representing a marginal 0.3% decline from the previous week’s 1,381,000.
Competitive Position Remains Intact
Notwithstanding the sequential decline, Lilly preserved its competitive standing in the GLP-1 marketplace. The pharmaceutical company maintained approximately 59% of weekly new prescription market share, consistent with the preceding week.
The GLP-1 category as a whole demonstrated continued expansion, increasing roughly 32% on a year-over-year basis.
Morgan Stanley analysts adopted a more bullish perspective regarding the injectable products. “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 launches for Lilly, emphasizing their potential influence on overall category expansion and competitive positioning in coming quarters.
While Lilly’s shares declined approximately 2%, Novo Nordisk’s U.S.-traded shares advanced roughly 2% on identical prescription data — a divergent market response that highlights how investors interpreted the Foundayo versus Wegovy performance gap.
Lilly’s injectable medications continue serving as the foundation of its GLP-1 franchise, with Mounjaro and Zepbound data demonstrating consistent sequential expansion through April 17.
