Mounjaro is Eli Lilly's branded tirzepatide for type-2 diabetes — the diabetes twin of Zepbound. The drug carries the same active ingredient as Zepbound, and the SURPASS Phase 3 program established it as a high-efficacy GLP-1/GIP option for glycemic control.
Key reads on this site: Mounjaro real-world data presented at OMA 2026 and elsewhere tracking with SURPASS-1 through SURPASS-5, the SURMOUNT-5 head-to-head against semaglutide that confirms the dual-agonist edge in obesity (and translates to T2D weight outcomes), and the kidney and HFpEF readouts that have broadened the cardiometabolic case.
Mounjaro became the world's #1 best-selling drug in Q1 2026 ($8.66B vs Keytruda's $7.9B), and the combined Mounjaro+Zepbound franchise now holds about 54.8% of US GLP-1 prescription share — up from 47% a year earlier. Q1 2026 YoY growth was 125% for Mounjaro and 80% for Zepbound, with Lilly raising 2026 revenue guidance to $82-85B.
Mounjaro sits alongside Zepbound on the FDA's April 30, 2026 proposal to exclude tirzepatide from the 503B bulks list. Stories here cover the trial data, payer coverage, market share, and the compounding fight.
Morningstar issued a pre-earnings note ahead of Eli Lilly's April 30 Q1 2026 report raising fair value to $870 from $770 following 2025 results and management guidance. Analysts project 27% top-line growth in 2026 and 20% in 2027, with double-digit growth through end of decade. Mounjaro/Zepbound represented 56% of total sales in 2025, projected to exceed 60% in 2026 with patent protection through 2036. The Q1 print will be the first read on Foundayo launch trajectory after the disappointing 1,390 / 3,707 prescription weeks 1-2.
The first definitive Phase 3B head-to-head trial of Lilly's tirzepatide versus Novo Nordisk's semaglutide in 750 patients with obesity over 72 weeks showed tirzepatide produced 21.6% mean weight loss vs semaglutide's 15.4%. 36.2% of tirzepatide patients achieved ≥25% weight loss vs 19.4% on semaglutide. Results published April 20 give Lilly a clear comparative data point in the GLP-1 market share battle.
CNBC reports Eli Lilly's Indian GLP-1 market share fell from 61% to 56% in March as 26 generic semaglutide brands from 13 companies entered the market following patent expiry. Novo Nordisk held steady at 25% after slashing Ozempic prices 38% and Wegovy prices 48%, while Lilly's Mounjaro remains priced 10x above the cheapest generics.
Tirzepatide (Mounjaro) Indian sales fell to ₹114 crore in March from ₹135 crore in February, while semaglutide sales rose to ₹59 crore. Semaglutide's GLP-1 segment share jumped to 33% from 25% as dozens of generics flood the market.
Biopharma acquisitions surged in Q1 2026 with 14 deals over $500M. Eli Lilly earned $65.2 billion in 2025, roughly half from Mounjaro and Zepbound, fueling an industry-wide M&A wave.
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%.