Pharmaceutical Giant Sees Shares Slip After Highly-Anticipated Foundayo Debut Fails to Impress Investors

Table of Contents Shares of Eli Lilly retreated roughly 2% Thursday following the release of weekly prescription figures for its GLP-1 medication lineup — with Foundayo’s performance falling notably short of investor expectations. Eli Lilly and Company, LLY The pharmaceutical giant’s newly launched oral weight management medication, Foundayo, generated 3,707 total prescriptions during its second week in the marketplace. While this represented growth from the initial week’s 1,390 prescriptions, it significantly underperformed the benchmark established by Novo Nordisk’s oral Wegovy formulation, which captured 18,410 prescriptions during its comparable second week in January. RBC Capital Markets analyst Trung Huynh delivered a straightforward 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 noted. J.P. Morgan’s Chris Schott acknowledged the slower trajectory compared to Wegovy but characterized it as expected. Wegovy benefited from earlier market entry and established brand awareness before Lilly’s competing product became available. Regulatory approval for Foundayo arrived on April 1, 2026. Prescription availability through LillyDirect commenced almost instantly, with product shipments beginning April 6. Widespread availability through retail pharmacies and telehealth platforms launched on April 9. The company has cautioned stakeholders against overinterpreting initial weekly data. Lilly emphasized that early figures may not reflect all participating pharmacy partners and should be “best interpreted over time rather than as a complete count.” Lilly’s established injectable offerings showed more consistent performance. Mounjaro reached 758,400 total prescriptions during the week ending April 17, advancing from 749,500 in the previous period. New Mounjaro prescriptions totaled 367,900, compared with 361,700 the week prior. Zepbound experienced modest softness. Total prescriptions decreased to 615,300 from 632,500, although new prescriptions increased slightly to 350,600 from 346,400. Across all three products, Lilly’s Mounjaro, Zepbound, and Foundayo portfolio reached 1,377,400 prescriptions — representing a 0.3% decline from the previous week’s 1,381,000. Notwithstanding the sequential decline, Lilly preserved its competitive standing within the expanding GLP-1 marketplace. The pharmaceutical company maintained approximately 59% of weekly new prescription market share, consistent with the preceding week. The GLP-1 therapeutic category as a whole continued its expansion trajectory, demonstrating roughly 32% year-over-year growth. Morgan Stanley analysts expressed a more constructive perspective regarding the injectable portfolio. “We see ~6% upside to ’26 M+Z ests,” the firm stated, referencing 2026 projections for Mounjaro and Zepbound. Morgan Stanley continues monitoring both medications as critical product franchises for Lilly, concentrating on their influence over category expansion and competitive positioning in coming periods. While Lilly’s equity declined approximately 2%, Novo Nordisk’s U.S.-traded shares gained roughly 2% on identical prescription information — a contrasting market response highlighting how investors interpreted the Foundayo-Wegovy performance gap. Lilly’s injectable therapies constitute the foundation of its GLP-1 franchise, with Mounjaro and Zepbound figures continuing to demonstrate consistent sequential advancement through April 17.