Lilly Shares Fall on Slight GLP-1 Rx Softness

Key Moments

Eli Lilly (NYSE:LLY) stock declined 2% as recent weekly GLP-1 prescription trends showed modest week-over-week pressure.
Total combined prescriptions for Mounjaro, Trulicity, Zepbound, and Foundayo slipped 0.3% to 1,503,100 for the week of April 17, 2026.

Mixed Weekly Trends Pressure Eli Lilly Stock

Investing.com — Shares of Eli Lilly and Company (NYSE:LLY) fell 2% after the latest weekly prescription data reflected a mixed picture across the company’s GLP-1 portfolio, according to IQVIA figures cited by Morgan Stanley.

Detailed Weekly Prescription Performance

For the week of April 17, 2026, Mounjaro generated approximately 758,400 total prescriptions and 367,900 new prescriptions. This compared with 749,500 total prescriptions and 361,700 new prescriptions in the prior week.

Zepbound recorded 615,300 total prescriptions and 350,600 new prescriptions for the same week, versus 632,500 total and 346,400 new prescriptions in the previous week.

Product	Week	Total Prescriptions	New Prescriptions
Mounjaro	Week of April 17, 2026	758,400	367,900
Mounjaro	Prior week	749,500	361,700
Zepbound	Week of April 17, 2026	615,300	350,600
Zepbound	Prior week	632,500	346,400

Franchise and Category-Level Metrics

Across Eli Lilly’s GLP-1 portfolio, combined prescriptions for Mounjaro, Trulicity, Zepbound, and Foundayo totaled 1,503,100 for the current week, compared with 1,508,000 a week earlier, a decline of 0.3%.

The combined total for Mounjaro, Zepbound, and Foundayo alone reached 1,377,400 prescriptions, slightly below 1,381,000 in the previous week, also a 0.3% decrease.

Eli Lilly’s overall GLP-1 franchise – including Mounjaro, Trulicity, and Zepbound – held approximately 59% weekly new prescription market share, unchanged from the prior week. The broader GLP-1 market grew about 32% year-over-year.

Foundayo Launch Tracking Behind Oral Wegovy

Foundayo, which received approval on April 1, 2026 and was launched on April 9, 2026, reached roughly 3,700 total and new prescriptions in its second week on the market.

This compares with approximately 18,400 total and new prescriptions for oral Wegovy in its second week following a January 5, 2026 launch.

Product	Milestone	Timing	Prescriptions in 2nd Week
Foundayo	Approval	April 1, 2026	~3,700 total and new
Foundayo	Launch	April 9, 2026	~3,700 total and new
Oral Wegovy	Launch	January 5, 2026	~18,400 total and new

Analyst View on Mounjaro and Zepbound

“We see ~6% upside to ’26 M+Z ests,” Morgan Stanley analysts commented, referring to Mounjaro and Zepbound estimates for 2026.

The firm indicated that it is tracking the launches of Mounjaro for type 2 diabetes and Zepbound for obesity as key product cycles for Eli Lilly, with particular attention on how these assets influence growth in the GLP-1 category and the company’s market share dynamics.