The GLP-1 market-share story moved decisively in Lilly's direction across 2025-2026. As of mid-2026, Eli Lilly's tirzepatide franchise (Mounjaro for T2D, Zepbound for obesity) holds about 54.8% of the US GLP-1 prescription share, up from 47% a year earlier; Mounjaro overtook Ozempic as the world's #1 best-selling drug in Q1 2026 ($8.66B vs Keytruda's $7.9B), and Lilly's Q1 2026 revenue grew 56% with 125% YoY growth for Mounjaro and 80% for Zepbound. The company raised 2026 guidance to $82-85B.
Novo Nordisk's response anchors on the Wegovy pill (oral semaglutide 25 mg) US launch January 5, 2026: 3M US prescriptions in five months, 65% of new GLP-1 prescriptions in the US, 82% to GLP-1-naive patients, and a $355M first quarter for the pill alone. Novo lifted 2026 guidance from a 5-13% to a 4-12% currency-adjusted decline, but the stock dropped 42% over the prior year against Lilly's 40% gain. The oral GLP-1 share war is the most-watched daily data point: by week ending June 5, oral Wegovy reached 33% of total Wegovy prescriptions while Lilly's Foundayo (orforglipron) had ~11,700 weekly scripts in Week 7 versus oral Wegovy's 67,000 in the same week.
Stories here cover IQVIA weekly trackers, analyst notes, and the share-shift narrative. See [[lilly]], [[novo-nordisk]], [[wegovy-pill]], and [[oral-glp-1]] for adjacent threads.
Coverage week of June 15-19 distilled the post-ADA market share story: Eli Lilly's tirzepatide franchise (Mounjaro for T2D, Zepbound for obesity) now holds 54.8% of US GLP-1 prescription share versus 47% a year earlier, with Q1 2026 YoY growth of 125% for Mounjaro and 80% for Zepbound and full-year revenue guidance raised to $82-85B. Novo Nordisk lifted its own 2026 guidance to a 4-12% currency-adjusted decline (improved from 5-13%) on Wegovy pill momentum (3M US scripts in five months, 65% of new prescriptions, 82% to GLP-1-naive patients), but Novo's stock has declined 42% over the past year against Lilly's 40% gain — the share-shift signal the ADA cycle crystallized. Lilly's seven additional retatrutide Phase 3 readouts across 2026 (TRIUMPH-7 chronic low-back pain, TRIUMPH-8 general obesity, TRIUMPH-9 obesity without T2D, plus OSA, MASLD, and cardiometabolic outcomes) extend the franchise gap.
Fierce Pharma's Oral GLP-1 Tracker reported the first weekly decline in Wegovy pill prescriptions since the January 5, 2026 launch: scripts dropped from ~143,000 to ~137,000 in the week ending May 8. Total Wegovy (injectable + pill) scripts climbed 1.3% w/w to ~446,000, taking obesity GLP-1 market share to 40.5%. Eli Lilly's Foundayo posted Week 5 IQVIA prescriptions of 10,248, up 40% w/w from Week 4's 7,335 — the steepest weekly growth in the launch series, attributed to mid-May commercial access activation at two of the three largest US PBMs. The cumulative US Wegovy pill user count crossed 1 million per Novo CEO Doustdar's May 14 commentary; the Wegovy injectable continues to be the largest US GLP-1 single-product line. The Wegovy pill plateau and Foundayo acceleration narrow the trajectory gap that has defined the oral-GLP-1 race since April.
Even with the first weekly Wegovy pill prescription decline since launch (~143K to ~137K week-ending May 8), the total Wegovy franchise (injectable + pill) climbed 1.3% week-over-week to approximately 446,000 prescriptions per the Fierce Pharma IQVIA tracker. Market share in the US obesity GLP-1 segment ticked up 0.1 percentage points to 40.5%. The injectable Wegovy 2.4 mg and Wegovy HD 7.2 mg formulations remain Novo's commercial anchor; the pill is the growth narrative. The 1.3% w/w injectable Wegovy growth aligns with Novo's H2 2026 international expansion plans and the EU approval expected before year-end. The data also confirms Zepbound (tirzepatide for obesity) continues to grow share faster than Wegovy on an absolute volume basis — the head-to-head dynamic that Cantor Fitzgerald and Barclays both cited in their May 5 LLY price target raises.
Analysts expect Novo's aggressive cuts to capture the lion's share of India's GLP-1 market in 12-18 months. Eli Lilly's Mounjaro currently dominates with ~79% share vs Novo's ~21%.